diff --git a/lfs.c b/lfs.c
index e2f90ee..1ff4f90 100644
--- a/lfs.c
+++ b/lfs.c
@@ -6,6 +6,70 @@
  */
 #include "lfs.h"
 
+
+/// Configuration mapping ///
+#ifdef LFS_STATICCFG
+// direct config towards user defines
+#define LFS_CFG_READ(lfs, block, off, buffer, size) \
+    ((void)lfs, lfs_read(block, off, buffer, size))
+#define LFS_CFG_PROG(lfs, block, off, buffer, size) \
+    ((void)lfs, lfs_prog(block, off, buffer, size))
+#define LFS_CFG_ERASE(lfs, block) \
+    ((void)lfs, lfs_erase(block))
+#define LFS_CFG_SYNC(lfs) \
+    ((void)lfs, lfs_sync())
+#define LFS_CFG_READ_SIZE(lfs)          ((void)lfs, LFS_READ_SIZE)
+#define LFS_CFG_PROG_SIZE(lfs)          ((void)lfs, LFS_PROG_SIZE)
+#define LFS_CFG_BLOCK_SIZE(lfs)         ((void)lfs, LFS_BLOCK_SIZE)
+#define LFS_CFG_BLOCK_COUNT(lfs)        ((void)lfs, LFS_BLOCK_COUNT)
+#define LFS_CFG_BLOCK_CYCLES(lfs)       ((void)lfs, LFS_BLOCK_CYCLES)
+#define LFS_CFG_CACHE_SIZE(lfs)         ((void)lfs, LFS_CACHE_SIZE)
+#define LFS_CFG_LOOKAHEAD_SIZE(lfs)     ((void)lfs, LFS_LOOKAHEAD_SIZE)
+#define LFS_CFG_READ_BUFFER(lfs)        ((void)lfs, LFS_READ_BUFFER)
+#define LFS_CFG_PROG_BUFFER(lfs)        ((void)lfs, LFS_PROG_BUFFER)
+#define LFS_CFG_LOOKAHEAD_BUFFER(lfs)   ((void)lfs, LFS_LOOKAHEAD_BUFFER)
+#define LFS_CFG_NAME_MAX(lfs)           ((void)lfs, LFS_NAME_MAX)
+#define LFS_CFG_FILE_MAX(lfs)           ((void)lfs, LFS_FILE_MAX)
+#define LFS_CFG_ATTR_MAX(lfs)           ((void)lfs, LFS_ATTR_MAX)
+#else
+// direct config towards dynamic lfs_config struct
+#define LFS_CFG_READ(lfs, block, off, buffer, size) \
+    lfs->cfg->read(lfs->cfg, block, off, buffer, size)
+#define LFS_CFG_PROG(lfs, block, off, buffer, size) \
+    lfs->cfg->prog(lfs->cfg, block, off, buffer, size)
+#define LFS_CFG_ERASE(lfs, block) \
+    lfs->cfg->erase(lfs->cfg, block)
+#define LFS_CFG_SYNC(lfs) \
+    lfs->cfg->sync(lfs->cfg)
+#define LFS_CFG_READ_SIZE(lfs)          lfs->cfg->read_size
+#define LFS_CFG_PROG_SIZE(lfs)          lfs->cfg->prog_size
+#define LFS_CFG_BLOCK_SIZE(lfs)         lfs->cfg->block_size
+#define LFS_CFG_BLOCK_COUNT(lfs)        lfs->cfg->block_count
+#define LFS_CFG_BLOCK_CYCLES(lfs)       lfs->cfg->block_cycles
+#define LFS_CFG_CACHE_SIZE(lfs)         lfs->cfg->cache_size
+#define LFS_CFG_LOOKAHEAD_SIZE(lfs)     lfs->cfg->lookahead_size
+#define LFS_CFG_READ_BUFFER(lfs)        lfs->cfg->read_buffer
+#define LFS_CFG_PROG_BUFFER(lfs)        lfs->cfg->prog_buffer
+#define LFS_CFG_LOOKAHEAD_BUFFER(lfs)   lfs->cfg->lookahead_buffer
+#define LFS_CFG_NAME_MAX(lfs)           lfs->cfg->name_max
+#define LFS_CFG_FILE_MAX(lfs)           lfs->cfg->file_max
+#define LFS_CFG_ATTR_MAX(lfs)           lfs->cfg->attr_max
+#endif
+
+#ifdef LFS_FILE_STATICCFG
+// direct config towards user defines
+#define LFS_FILE_CFG_BUFFER(file)       LFS_FILE_BUFFER
+#define LFS_FILE_CFG_ATTRS(file)        LFS_FILE_ATTRS
+#define LFS_FILE_CFG_ATTR_COUNT(file)   LFS_FILE_ATTR_COUNT
+#else
+// direct config towards dynamic lfs_config struct
+#define LFS_FILE_CFG_BUFFER(file)       file->cfg->buffer
+#define LFS_FILE_CFG_ATTRS(file)        file->cfg->attrs
+#define LFS_FILE_CFG_ATTR_COUNT(file)   file->cfg->attr_count
+#endif
+
+
+/// Internal littlefs constants ///
 #define LFS_BLOCK_NULL ((lfs_block_t)-1)
 #define LFS_BLOCK_INLINE ((lfs_block_t)-2)
 
@@ -19,7 +83,7 @@ static inline void lfs_cache_drop(lfs_t *lfs, lfs_cache_t *rcache) {
 
 static inline void lfs_cache_zero(lfs_t *lfs, lfs_cache_t *pcache) {
     // zero to avoid information leak
-    memset(pcache->buffer, 0xff, lfs->cfg->cache_size);
+    memset(pcache->buffer, 0xff, LFS_CFG_CACHE_SIZE(lfs));
     pcache->block = LFS_BLOCK_NULL;
 }
 
@@ -28,8 +92,8 @@ static int lfs_bd_read(lfs_t *lfs,
         lfs_block_t block, lfs_off_t off,
         void *buffer, lfs_size_t size) {
     uint8_t *data = buffer;
-    if (block >= lfs->cfg->block_count ||
-            off+size > lfs->cfg->block_size) {
+    if (block >= LFS_CFG_BLOCK_COUNT(lfs) ||
+            off+size > LFS_CFG_BLOCK_SIZE(lfs)) {
         return LFS_ERR_CORRUPT;
     }
 
@@ -70,11 +134,11 @@ static int lfs_bd_read(lfs_t *lfs,
             diff = lfs_min(diff, rcache->off-off);
         }
 
-        if (size >= hint && off % lfs->cfg->read_size == 0 &&
-                size >= lfs->cfg->read_size) {
+        if (size >= hint && off % LFS_CFG_READ_SIZE(lfs) == 0 &&
+                size >= LFS_CFG_READ_SIZE(lfs)) {
             // bypass cache?
-            diff = lfs_aligndown(diff, lfs->cfg->read_size);
-            int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
+            diff = lfs_aligndown(diff, LFS_CFG_READ_SIZE(lfs));
+            int err = LFS_CFG_READ(lfs, block, off, data, diff);
             if (err) {
                 return err;
             }
@@ -86,16 +150,16 @@ static int lfs_bd_read(lfs_t *lfs,
         }
 
         // load to cache, first condition can no longer fail
-        LFS_ASSERT(block < lfs->cfg->block_count);
+        LFS_ASSERT(block < LFS_CFG_BLOCK_COUNT(lfs));
         rcache->block = block;
-        rcache->off = lfs_aligndown(off, lfs->cfg->read_size);
+        rcache->off = lfs_aligndown(off, LFS_CFG_READ_SIZE(lfs));
         rcache->size = lfs_min(
                 lfs_min(
-                    lfs_alignup(off+hint, lfs->cfg->read_size),
-                    lfs->cfg->block_size)
+                    lfs_alignup(off+hint, LFS_CFG_READ_SIZE(lfs)),
+                    LFS_CFG_BLOCK_SIZE(lfs))
                 - rcache->off,
-                lfs->cfg->cache_size);
-        int err = lfs->cfg->read(lfs->cfg, rcache->block,
+                LFS_CFG_CACHE_SIZE(lfs));
+        int err = LFS_CFG_READ(lfs, rcache->block,
                 rcache->off, rcache->buffer, rcache->size);
         LFS_ASSERT(err <= 0);
         if (err) {
@@ -138,9 +202,9 @@ static int lfs_bd_cmp(lfs_t *lfs,
 static int lfs_bd_flush(lfs_t *lfs,
         lfs_cache_t *pcache, lfs_cache_t *rcache, bool validate) {
     if (pcache->block != LFS_BLOCK_NULL && pcache->block != LFS_BLOCK_INLINE) {
-        LFS_ASSERT(pcache->block < lfs->cfg->block_count);
-        lfs_size_t diff = lfs_alignup(pcache->size, lfs->cfg->prog_size);
-        int err = lfs->cfg->prog(lfs->cfg, pcache->block,
+        LFS_ASSERT(pcache->block < LFS_CFG_BLOCK_COUNT(lfs));
+        lfs_size_t diff = lfs_alignup(pcache->size, LFS_CFG_PROG_SIZE(lfs));
+        int err = LFS_CFG_PROG(lfs, pcache->block,
                 pcache->off, pcache->buffer, diff);
         LFS_ASSERT(err <= 0);
         if (err) {
@@ -177,7 +241,7 @@ static int lfs_bd_sync(lfs_t *lfs,
         return err;
     }
 
-    err = lfs->cfg->sync(lfs->cfg);
+    err = LFS_CFG_SYNC(lfs);
     LFS_ASSERT(err <= 0);
     return err;
 }
@@ -187,16 +251,16 @@ static int lfs_bd_prog(lfs_t *lfs,
         lfs_block_t block, lfs_off_t off,
         const void *buffer, lfs_size_t size) {
     const uint8_t *data = buffer;
-    LFS_ASSERT(block == LFS_BLOCK_INLINE || block < lfs->cfg->block_count);
-    LFS_ASSERT(off + size <= lfs->cfg->block_size);
+    LFS_ASSERT(block == LFS_BLOCK_INLINE || block < LFS_CFG_BLOCK_COUNT(lfs));
+    LFS_ASSERT(off + size <= LFS_CFG_BLOCK_SIZE(lfs));
 
     while (size > 0) {
         if (block == pcache->block &&
                 off >= pcache->off &&
-                off < pcache->off + lfs->cfg->cache_size) {
+                off < pcache->off + LFS_CFG_CACHE_SIZE(lfs)) {
             // already fits in pcache?
             lfs_size_t diff = lfs_min(size,
-                    lfs->cfg->cache_size - (off-pcache->off));
+                    LFS_CFG_CACHE_SIZE(lfs) - (off-pcache->off));
             memcpy(&pcache->buffer[off-pcache->off], data, diff);
 
             data += diff;
@@ -204,7 +268,7 @@ static int lfs_bd_prog(lfs_t *lfs,
             size -= diff;
 
             pcache->size = lfs_max(pcache->size, off - pcache->off);
-            if (pcache->size == lfs->cfg->cache_size) {
+            if (pcache->size == LFS_CFG_CACHE_SIZE(lfs)) {
                 // eagerly flush out pcache if we fill up
                 int err = lfs_bd_flush(lfs, pcache, rcache, validate);
                 if (err) {
@@ -221,7 +285,7 @@ static int lfs_bd_prog(lfs_t *lfs,
 
         // prepare pcache, first condition can no longer fail
         pcache->block = block;
-        pcache->off = lfs_aligndown(off, lfs->cfg->prog_size);
+        pcache->off = lfs_aligndown(off, LFS_CFG_PROG_SIZE(lfs));
         pcache->size = 0;
     }
 
@@ -229,8 +293,8 @@ static int lfs_bd_prog(lfs_t *lfs,
 }
 
 static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block) {
-    LFS_ASSERT(block < lfs->cfg->block_count);
-    int err = lfs->cfg->erase(lfs->cfg, block);
+    LFS_ASSERT(block < LFS_CFG_BLOCK_COUNT(lfs));
+    int err = LFS_CFG_ERASE(lfs, block);
     LFS_ASSERT(err <= 0);
     return err;
 }
@@ -442,7 +506,7 @@ static int lfs1_traverse(lfs_t *lfs,
 static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
     lfs_t *lfs = (lfs_t*)p;
     lfs_block_t off = ((block - lfs->free.off)
-            + lfs->cfg->block_count) % lfs->cfg->block_count;
+            + LFS_CFG_BLOCK_COUNT(lfs)) % LFS_CFG_BLOCK_COUNT(lfs);
 
     if (off < lfs->free.size) {
         lfs->free.buffer[off / 32] |= 1U << (off % 32);
@@ -452,13 +516,13 @@ static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
 }
 
 static void lfs_alloc_ack(lfs_t *lfs) {
-    lfs->free.ack = lfs->cfg->block_count;
+    lfs->free.ack = LFS_CFG_BLOCK_COUNT(lfs);
 }
 
 // Invalidate the lookahead buffer. This is done during mounting and
 // failed traversals
 static void lfs_alloc_reset(lfs_t *lfs) {
-    lfs->free.off = lfs->seed % lfs->cfg->block_size;
+    lfs->free.off = lfs->seed % LFS_CFG_BLOCK_SIZE(lfs);
     lfs->free.size = 0;
     lfs->free.i = 0;
     lfs_alloc_ack(lfs);
@@ -473,7 +537,7 @@ static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
 
             if (!(lfs->free.buffer[off / 32] & (1U << (off % 32)))) {
                 // found a free block
-                *block = (lfs->free.off + off) % lfs->cfg->block_count;
+                *block = (lfs->free.off + off) % LFS_CFG_BLOCK_COUNT(lfs);
 
                 // eagerly find next off so an alloc ack can
                 // discredit old lookahead blocks
@@ -496,12 +560,12 @@ static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
         }
 
         lfs->free.off = (lfs->free.off + lfs->free.size)
-                % lfs->cfg->block_count;
-        lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size, lfs->free.ack);
+                % LFS_CFG_BLOCK_COUNT(lfs);
+        lfs->free.size = lfs_min(8*LFS_CFG_LOOKAHEAD_SIZE(lfs), lfs->free.ack);
         lfs->free.i = 0;
 
         // find mask of free blocks from tree
-        memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
+        memset(lfs->free.buffer, 0, LFS_CFG_LOOKAHEAD_SIZE(lfs));
         int err = lfs_fs_traverseraw(lfs, lfs_alloc_lookahead, lfs, true);
         if (err) {
             lfs_alloc_reset(lfs);
@@ -585,7 +649,7 @@ static int lfs_dir_getread(lfs_t *lfs, const lfs_mdir_t *dir,
         lfs_tag_t gmask, lfs_tag_t gtag,
         lfs_off_t off, void *buffer, lfs_size_t size) {
     uint8_t *data = buffer;
-    if (off+size > lfs->cfg->block_size) {
+    if (off+size > LFS_CFG_BLOCK_SIZE(lfs)) {
         return LFS_ERR_CORRUPT;
     }
 
@@ -628,9 +692,9 @@ static int lfs_dir_getread(lfs_t *lfs, const lfs_mdir_t *dir,
 
         // load to cache, first condition can no longer fail
         rcache->block = LFS_BLOCK_INLINE;
-        rcache->off = lfs_aligndown(off, lfs->cfg->read_size);
-        rcache->size = lfs_min(lfs_alignup(off+hint, lfs->cfg->read_size),
-                lfs->cfg->cache_size);
+        rcache->off = lfs_aligndown(off, LFS_CFG_READ_SIZE(lfs));
+        rcache->size = lfs_min(lfs_alignup(off+hint, LFS_CFG_READ_SIZE(lfs)),
+                LFS_CFG_CACHE_SIZE(lfs));
         int err = lfs_dir_getslice(lfs, dir, gmask, gtag,
                 rcache->off, rcache->buffer, rcache->size);
         if (err < 0) {
@@ -773,7 +837,8 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
 
     // if either block address is invalid we return LFS_ERR_CORRUPT here,
     // otherwise later writes to the pair could fail
-    if (pair[0] >= lfs->cfg->block_count || pair[1] >= lfs->cfg->block_count) {
+    if (pair[0] >= LFS_CFG_BLOCK_COUNT(lfs) ||
+            pair[1] >= LFS_CFG_BLOCK_COUNT(lfs)) {
         return LFS_ERR_CORRUPT;
     }
 
@@ -819,7 +884,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
             lfs_tag_t tag;
             off += lfs_tag_dsize(ptag);
             int err = lfs_bd_read(lfs,
-                    NULL, &lfs->rcache, lfs->cfg->block_size,
+                    NULL, &lfs->rcache, LFS_CFG_BLOCK_SIZE(lfs),
                     dir->pair[0], off, &tag, sizeof(tag));
             if (err) {
                 if (err == LFS_ERR_CORRUPT) {
@@ -836,9 +901,9 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
             // next commit not yet programmed or we're not in valid range
             if (!lfs_tag_isvalid(tag)) {
                 dir->erased = (lfs_tag_type1(ptag) == LFS_TYPE_CRC &&
-                        dir->off % lfs->cfg->prog_size == 0);
+                        dir->off % LFS_CFG_PROG_SIZE(lfs) == 0);
                 break;
-            } else if (off + lfs_tag_dsize(tag) > lfs->cfg->block_size) {
+            } else if (off + lfs_tag_dsize(tag) > LFS_CFG_BLOCK_SIZE(lfs)) {
                 dir->erased = false;
                 break;
             }
@@ -849,7 +914,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                 // check the crc attr
                 uint32_t dcrc;
                 err = lfs_bd_read(lfs,
-                        NULL, &lfs->rcache, lfs->cfg->block_size,
+                        NULL, &lfs->rcache, LFS_CFG_BLOCK_SIZE(lfs),
                         dir->pair[0], off+sizeof(tag), &dcrc, sizeof(dcrc));
                 if (err) {
                     if (err == LFS_ERR_CORRUPT) {
@@ -890,7 +955,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
             for (lfs_off_t j = sizeof(tag); j < lfs_tag_dsize(tag); j++) {
                 uint8_t dat;
                 err = lfs_bd_read(lfs,
-                        NULL, &lfs->rcache, lfs->cfg->block_size,
+                        NULL, &lfs->rcache, LFS_CFG_BLOCK_SIZE(lfs),
                         dir->pair[0], off+j, &dat, 1);
                 if (err) {
                     if (err == LFS_ERR_CORRUPT) {
@@ -923,7 +988,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                 tempsplit = (lfs_tag_chunk(tag) & 1);
 
                 err = lfs_bd_read(lfs,
-                        NULL, &lfs->rcache, lfs->cfg->block_size,
+                        NULL, &lfs->rcache, LFS_CFG_BLOCK_SIZE(lfs),
                         dir->pair[0], off+sizeof(tag), &temptail, 8);
                 if (err) {
                     if (err == LFS_ERR_CORRUPT) {
@@ -1264,7 +1329,7 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
     const uint32_t crc1 = commit->crc;
     // align to program units
     const lfs_off_t end = lfs_alignup(off1 + 2*sizeof(uint32_t),
-            lfs->cfg->prog_size);
+            LFS_CFG_PROG_SIZE(lfs));
 
     // create crc tags to fill up remainder of commit, note that
     // padding is not crced, which lets fetches skip padding but
@@ -1486,9 +1551,9 @@ static int lfs_dir_compact(lfs_t *lfs,
         // cleanup delete, and we cap at half a block to give room
         // for metadata updates.
         if (end - begin < 0xff &&
-                size <= lfs_min(lfs->cfg->block_size - 36,
-                    lfs_alignup(lfs->cfg->block_size/2,
-                        lfs->cfg->prog_size))) {
+                size <= lfs_min(LFS_CFG_BLOCK_SIZE(lfs) - 36,
+                    lfs_alignup(LFS_CFG_BLOCK_SIZE(lfs)/2,
+                        LFS_CFG_PROG_SIZE(lfs)))) {
             break;
         }
 
@@ -1502,7 +1567,7 @@ static int lfs_dir_compact(lfs_t *lfs,
             // if we fail to split, we may be able to overcompact, unless
             // we're too big for even the full block, in which case our
             // only option is to error
-            if (err == LFS_ERR_NOSPC && size <= lfs->cfg->block_size - 36) {
+            if (err == LFS_ERR_NOSPC && size <= LFS_CFG_BLOCK_SIZE(lfs) - 36) {
                 break;
             }
             return err;
@@ -1519,8 +1584,8 @@ static int lfs_dir_compact(lfs_t *lfs,
     // 1. block_cycles = 1, which would prevent relocations from terminating
     // 2. block_cycles = 2n, which, due to aliasing, would only ever relocate
     //    one metadata block in the pair, effectively making this useless
-    if (lfs->cfg->block_cycles > 0 &&
-            (dir->rev % ((lfs->cfg->block_cycles+1)|1) == 0)) {
+    if (LFS_CFG_BLOCK_CYCLES(lfs) > 0 &&
+            (dir->rev % ((LFS_CFG_BLOCK_CYCLES(lfs)+1)|1) == 0)) {
         if (lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) == 0) {
             // oh no! we're writing too much to the superblock,
             // should we expand?
@@ -1531,7 +1596,7 @@ static int lfs_dir_compact(lfs_t *lfs,
 
             // do we have extra space? littlefs can't reclaim this space
             // by itself, so expand cautiously
-            if ((lfs_size_t)res < lfs->cfg->block_count/2) {
+            if ((lfs_size_t)res < LFS_CFG_BLOCK_COUNT(lfs)/2) {
                 LFS_DEBUG("Expanding superblock at rev %"PRIu32, dir->rev);
                 int err = lfs_dir_split(lfs, dir, attrs, attrcount,
                         source, begin, end);
@@ -1572,7 +1637,7 @@ static int lfs_dir_compact(lfs_t *lfs,
                 .crc = 0xffffffff,
 
                 .begin = 0,
-                .end = lfs->cfg->block_size - 8,
+                .end = LFS_CFG_BLOCK_SIZE(lfs) - 8,
             };
 
             // erase block to write to
@@ -1663,7 +1728,7 @@ static int lfs_dir_compact(lfs_t *lfs,
             }
 
             // successful compaction, swap dir pair to indicate most recent
-            LFS_ASSERT(commit.off % lfs->cfg->prog_size == 0);
+            LFS_ASSERT(commit.off % LFS_CFG_PROG_SIZE(lfs) == 0);
             lfs_pair_swap(dir->pair);
             dir->count = end - begin;
             dir->off = commit.off;
@@ -1722,7 +1787,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
     for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
         if (dir != &f->m && lfs_pair_cmp(f->m.pair, dir->pair) == 0 &&
                 f->type == LFS_TYPE_REG && (f->flags & LFS_F_INLINE) &&
-                f->ctz.size > lfs->cfg->cache_size) {
+                f->ctz.size > LFS_CFG_CACHE_SIZE(lfs)) {
             int err = lfs_file_outline(lfs, f);
             if (err) {
                 return err;
@@ -1780,7 +1845,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
             .crc = 0xffffffff,
 
             .begin = dir->off,
-            .end = lfs->cfg->block_size - 8,
+            .end = LFS_CFG_BLOCK_SIZE(lfs) - 8,
         };
 
         // traverse attrs that need to be written out
@@ -1836,7 +1901,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
         }
 
         // successful commit, update dir
-        LFS_ASSERT(commit.off % lfs->cfg->prog_size == 0);
+        LFS_ASSERT(commit.off % LFS_CFG_PROG_SIZE(lfs) == 0);
         dir->off = commit.off;
         dir->etag = commit.ptag;
         // and update gstate
@@ -2191,7 +2256,7 @@ int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir) {
 /// File index list operations ///
 static int lfs_ctz_index(lfs_t *lfs, lfs_off_t *off) {
     lfs_off_t size = *off;
-    lfs_off_t b = lfs->cfg->block_size - 2*4;
+    lfs_off_t b = LFS_CFG_BLOCK_SIZE(lfs) - 2*4;
     lfs_off_t i = size / b;
     if (i == 0) {
         return 0;
@@ -2268,7 +2333,7 @@ static int lfs_ctz_extend(lfs_t *lfs,
             noff = noff + 1;
 
             // just copy out the last block if it is incomplete
-            if (noff != lfs->cfg->block_size) {
+            if (noff != LFS_CFG_BLOCK_SIZE(lfs)) {
                 for (lfs_off_t i = 0; i < noff; i++) {
                     uint8_t data;
                     err = lfs_bd_read(lfs,
@@ -2379,26 +2444,18 @@ static int lfs_ctz_traverse(lfs_t *lfs,
 
 
 /// Top level file operations ///
-int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
-        const char *path, int flags,
-        const struct lfs_file_config *cfg) {
-    LFS_TRACE("lfs_file_opencfg(%p, %p, \"%s\", %x, %p {"
-                 ".buffer=%p, .attrs=%p, .attr_count=%"PRIu32"})",
-            (void*)lfs, (void*)file, path, flags,
-            (void*)cfg, cfg->buffer, (void*)cfg->attrs, cfg->attr_count);
-
+static int lfs_file_opencommon(lfs_t *lfs, lfs_file_t *file,
+        const char *path, int flags) {
     // deorphan if we haven't yet, needed at most once after poweron
     if ((flags & 3) != LFS_O_RDONLY) {
         int err = lfs_fs_forceconsistency(lfs);
         if (err) {
-            LFS_TRACE("lfs_file_opencfg -> %d", err);
             return err;
         }
     }
 
     // setup simple file details
     int err;
-    file->cfg = cfg;
     file->flags = flags | LFS_F_OPENED;
     file->pos = 0;
     file->off = 0;
@@ -2461,14 +2518,16 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         lfs_ctz_fromle32(&file->ctz);
     }
 
+#if !defined(LFS_FILE_STATICCFG) || LFS_FILE_ATTR_COUNT > 0
     // fetch attrs
-    for (unsigned i = 0; i < file->cfg->attr_count; i++) {
+    for (unsigned i = 0; i < LFS_FILE_CFG_ATTR_COUNT(file); i++) {
         if ((file->flags & 3) != LFS_O_WRONLY) {
             lfs_stag_t res = lfs_dir_get(lfs, &file->m,
                     LFS_MKTAG(0x7ff, 0x3ff, 0),
-                    LFS_MKTAG(LFS_TYPE_USERATTR + file->cfg->attrs[i].type,
-                        file->id, file->cfg->attrs[i].size),
-                        file->cfg->attrs[i].buffer);
+                    LFS_MKTAG(
+                        LFS_TYPE_USERATTR + LFS_FILE_CFG_ATTRS(file)[i].type,
+                        file->id, LFS_FILE_CFG_ATTRS(file)[i].size),
+                        LFS_FILE_CFG_ATTRS(file)[i].buffer);
             if (res < 0 && res != LFS_ERR_NOENT) {
                 err = res;
                 goto cleanup;
@@ -2476,7 +2535,7 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         }
 
         if ((file->flags & 3) != LFS_O_RDONLY) {
-            if (file->cfg->attrs[i].size > lfs->attr_max) {
+            if (LFS_FILE_CFG_ATTRS(file)[i].size > lfs->attr_max) {
                 err = LFS_ERR_NOSPC;
                 goto cleanup;
             }
@@ -2484,12 +2543,13 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
             file->flags |= LFS_F_DIRTY;
         }
     }
+#endif
 
     // allocate buffer if needed
-    if (file->cfg->buffer) {
-        file->cache.buffer = file->cfg->buffer;
+    if (LFS_FILE_CFG_BUFFER(file)) {
+        file->cache.buffer = LFS_FILE_CFG_BUFFER(file);
     } else {
-        file->cache.buffer = lfs_malloc(lfs->cfg->cache_size);
+        file->cache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
         if (!file->cache.buffer) {
             err = LFS_ERR_NOMEM;
             goto cleanup;
@@ -2506,7 +2566,7 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         file->flags |= LFS_F_INLINE;
         file->cache.block = file->ctz.head;
         file->cache.off = 0;
-        file->cache.size = lfs->cfg->cache_size;
+        file->cache.size = LFS_CFG_CACHE_SIZE(lfs);
 
         // don't always read (may be new/trunc file)
         if (file->ctz.size > 0) {
@@ -2522,14 +2582,12 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         }
     }
 
-    LFS_TRACE("lfs_file_opencfg -> %d", 0);
     return 0;
 
 cleanup:
     // clean up lingering resources
     file->flags |= LFS_F_ERRED;
     lfs_file_close(lfs, file);
-    LFS_TRACE("lfs_file_opencfg -> %d", err);
     return err;
 }
 
@@ -2537,12 +2595,30 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags) {
     LFS_TRACE("lfs_file_open(%p, %p, \"%s\", %x)",
             (void*)lfs, (void*)file, path, flags);
+#ifndef LFS_FILE_STATICCFG
     static const struct lfs_file_config defaults = {0};
-    int err = lfs_file_opencfg(lfs, file, path, flags, &defaults);
+    file->cfg = &defaults;
+#endif
+    int err = lfs_file_opencommon(lfs, file, path, flags);
     LFS_TRACE("lfs_file_open -> %d", err);
     return err;
 }
 
+#if !defined(LFS_FILE_STATICCFG)
+int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
+        const char *path, int flags,
+        const struct lfs_file_config *cfg) {
+    LFS_TRACE("lfs_file_opencfg(%p, %p, \"%s\", %x, %p {"
+                 ".buffer=%p, .attrs=%p, .attr_count=%"PRIu32"})",
+            (void*)lfs, (void*)file, path, flags,
+            (void*)cfg, cfg->buffer, (void*)cfg->attrs, cfg->attr_count);
+    file->cfg = cfg;
+    int err = lfs_file_opencommon(lfs, file, path, flags);
+    LFS_TRACE("lfs_file_opencfg -> %d", err);
+    return err;
+}
+#endif
+
 int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
     LFS_TRACE("lfs_file_close(%p, %p)", (void*)lfs, (void*)file);
     LFS_ASSERT(file->flags & LFS_F_OPENED);
@@ -2558,7 +2634,7 @@ int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
     }
 
     // clean up memory
-    if (!file->cfg->buffer) {
+    if (!LFS_FILE_CFG_BUFFER(file)) {
         lfs_free(file->cache.buffer);
     }
 
@@ -2620,7 +2696,7 @@ static int lfs_file_relocate(lfs_t *lfs, lfs_file_t *file) {
         }
 
         // copy over new state of file
-        memcpy(file->cache.buffer, lfs->pcache.buffer, lfs->cfg->cache_size);
+        memcpy(file->cache.buffer, lfs->pcache.buffer, LFS_CFG_CACHE_SIZE(lfs));
         file->cache.block = lfs->pcache.block;
         file->cache.off = lfs->pcache.off;
         file->cache.size = lfs->pcache.size;
@@ -2773,7 +2849,7 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
         err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
                 {LFS_MKTAG(type, file->id, size), buffer},
                 {LFS_MKTAG(LFS_FROM_USERATTRS, file->id,
-                    file->cfg->attr_count), file->cfg->attrs}));
+                    LFS_FILE_CFG_ATTR_COUNT(file)), LFS_FILE_CFG_ATTRS(file)}));
         if (err) {
             file->flags |= LFS_F_ERRED;
             LFS_TRACE("lfs_file_sync -> %d", err);
@@ -2818,7 +2894,7 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
     while (nsize > 0) {
         // check if we need a new block
         if (!(file->flags & LFS_F_READING) ||
-                file->off == lfs->cfg->block_size) {
+                file->off == LFS_CFG_BLOCK_SIZE(lfs)) {
             if (!(file->flags & LFS_F_INLINE)) {
                 int err = lfs_ctz_find(lfs, NULL, &file->cache,
                         file->ctz.head, file->ctz.size,
@@ -2836,10 +2912,10 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
         }
 
         // read as much as we can in current block
-        lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->off);
+        lfs_size_t diff = lfs_min(nsize, LFS_CFG_BLOCK_SIZE(lfs) - file->off);
         if (file->flags & LFS_F_INLINE) {
             int err = lfs_dir_getread(lfs, &file->m,
-                    NULL, &file->cache, lfs->cfg->block_size,
+                    NULL, &file->cache, LFS_CFG_BLOCK_SIZE(lfs),
                     LFS_MKTAG(0xfff, 0x1ff, 0),
                     LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0),
                     file->off, data, diff);
@@ -2849,7 +2925,7 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
             }
         } else {
             int err = lfs_bd_read(lfs,
-                    NULL, &file->cache, lfs->cfg->block_size,
+                    NULL, &file->cache, LFS_CFG_BLOCK_SIZE(lfs),
                     file->block, file->off, data, diff);
             if (err) {
                 LFS_TRACE("lfs_file_read -> %d", err);
@@ -2913,7 +2989,7 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
     if ((file->flags & LFS_F_INLINE) &&
             lfs_max(file->pos+nsize, file->ctz.size) >
             lfs_min(0x3fe, lfs_min(
-                lfs->cfg->cache_size, lfs->cfg->block_size/8))) {
+                LFS_CFG_CACHE_SIZE(lfs), LFS_CFG_BLOCK_SIZE(lfs)/8))) {
         // inline file doesn't fit anymore
         int err = lfs_file_outline(lfs, file);
         if (err) {
@@ -2926,7 +3002,7 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
     while (nsize > 0) {
         // check if we need a new block
         if (!(file->flags & LFS_F_WRITING) ||
-                file->off == lfs->cfg->block_size) {
+                file->off == LFS_CFG_BLOCK_SIZE(lfs)) {
             if (!(file->flags & LFS_F_INLINE)) {
                 if (!(file->flags & LFS_F_WRITING) && file->pos > 0) {
                     // find out which block we're extending from
@@ -2962,7 +3038,7 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
         }
 
         // program as much as we can in current block
-        lfs_size_t diff = lfs_min(nsize, lfs->cfg->block_size - file->off);
+        lfs_size_t diff = lfs_min(nsize, LFS_CFG_BLOCK_SIZE(lfs) - file->off);
         while (true) {
             int err = lfs_bd_prog(lfs, &file->cache, &lfs->rcache, true,
                     file->block, file->off, data, diff);
@@ -3459,25 +3535,24 @@ int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type) {
 
 
 /// Filesystem operations ///
-static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
-    lfs->cfg = cfg;
+static int lfs_initcommon(lfs_t *lfs) {
     int err = 0;
 
     // validate that the lfs-cfg sizes were initiated properly before
     // performing any arithmetic logics with them
-    LFS_ASSERT(lfs->cfg->read_size != 0);
-    LFS_ASSERT(lfs->cfg->prog_size != 0);
-    LFS_ASSERT(lfs->cfg->cache_size != 0);
+    LFS_ASSERT(LFS_CFG_READ_SIZE(lfs) != 0);
+    LFS_ASSERT(LFS_CFG_PROG_SIZE(lfs) != 0);
+    LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) != 0);
 
     // check that block size is a multiple of cache size is a multiple
     // of prog and read sizes
-    LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->read_size == 0);
-    LFS_ASSERT(lfs->cfg->cache_size % lfs->cfg->prog_size == 0);
-    LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->cache_size == 0);
+    LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) % LFS_CFG_READ_SIZE(lfs) == 0);
+    LFS_ASSERT(LFS_CFG_CACHE_SIZE(lfs) % LFS_CFG_PROG_SIZE(lfs) == 0);
+    LFS_ASSERT(LFS_CFG_BLOCK_SIZE(lfs) % LFS_CFG_CACHE_SIZE(lfs) == 0);
 
     // check that the block size is large enough to fit ctz pointers
-    LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
-            <= lfs->cfg->block_size);
+    LFS_ASSERT(4*lfs_npw2(0xffffffff / (LFS_CFG_BLOCK_SIZE(lfs)-2*4))
+            <= LFS_CFG_BLOCK_SIZE(lfs));
 
     // block_cycles = 0 is no longer supported.
     //
@@ -3485,14 +3560,14 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     // metadata logs as a part of wear leveling. Suggested values are in the
     // range of 100-1000, or set block_cycles to -1 to disable block-level
     // wear-leveling.
-    LFS_ASSERT(lfs->cfg->block_cycles != 0);
+    LFS_ASSERT(LFS_CFG_BLOCK_CYCLES(lfs) != 0);
 
 
     // setup read cache
-    if (lfs->cfg->read_buffer) {
-        lfs->rcache.buffer = lfs->cfg->read_buffer;
+    if (LFS_CFG_READ_BUFFER(lfs)) {
+        lfs->rcache.buffer = LFS_CFG_READ_BUFFER(lfs);
     } else {
-        lfs->rcache.buffer = lfs_malloc(lfs->cfg->cache_size);
+        lfs->rcache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
         if (!lfs->rcache.buffer) {
             err = LFS_ERR_NOMEM;
             goto cleanup;
@@ -3500,10 +3575,10 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     }
 
     // setup program cache
-    if (lfs->cfg->prog_buffer) {
-        lfs->pcache.buffer = lfs->cfg->prog_buffer;
+    if (LFS_CFG_PROG_BUFFER(lfs)) {
+        lfs->pcache.buffer = LFS_CFG_PROG_BUFFER(lfs);
     } else {
-        lfs->pcache.buffer = lfs_malloc(lfs->cfg->cache_size);
+        lfs->pcache.buffer = lfs_malloc(LFS_CFG_CACHE_SIZE(lfs));
         if (!lfs->pcache.buffer) {
             err = LFS_ERR_NOMEM;
             goto cleanup;
@@ -3515,13 +3590,13 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs_cache_zero(lfs, &lfs->pcache);
 
     // setup lookahead, must be multiple of 64-bits, 32-bit aligned
-    LFS_ASSERT(lfs->cfg->lookahead_size > 0);
-    LFS_ASSERT(lfs->cfg->lookahead_size % 8 == 0 &&
-            (uintptr_t)lfs->cfg->lookahead_buffer % 4 == 0);
-    if (lfs->cfg->lookahead_buffer) {
-        lfs->free.buffer = lfs->cfg->lookahead_buffer;
+    LFS_ASSERT(LFS_CFG_LOOKAHEAD_SIZE(lfs) > 0);
+    LFS_ASSERT(LFS_CFG_LOOKAHEAD_SIZE(lfs) % 8 == 0 &&
+            (uintptr_t)LFS_CFG_LOOKAHEAD_BUFFER(lfs) % 4 == 0);
+    if (LFS_CFG_LOOKAHEAD_BUFFER(lfs)) {
+        lfs->free.buffer = LFS_CFG_LOOKAHEAD_BUFFER(lfs);
     } else {
-        lfs->free.buffer = lfs_malloc(lfs->cfg->lookahead_size);
+        lfs->free.buffer = lfs_malloc(LFS_CFG_LOOKAHEAD_SIZE(lfs));
         if (!lfs->free.buffer) {
             err = LFS_ERR_NOMEM;
             goto cleanup;
@@ -3529,20 +3604,20 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     }
 
     // check that the size limits are sane
-    LFS_ASSERT(lfs->cfg->name_max <= LFS_NAME_MAX);
-    lfs->name_max = lfs->cfg->name_max;
+    LFS_ASSERT(LFS_CFG_NAME_MAX(lfs) <= LFS_NAME_MAX);
+    lfs->name_max = LFS_CFG_NAME_MAX(lfs);
     if (!lfs->name_max) {
         lfs->name_max = LFS_NAME_MAX;
     }
 
-    LFS_ASSERT(lfs->cfg->file_max <= LFS_FILE_MAX);
-    lfs->file_max = lfs->cfg->file_max;
+    LFS_ASSERT(LFS_CFG_FILE_MAX(lfs) <= LFS_FILE_MAX);
+    lfs->file_max = LFS_CFG_FILE_MAX(lfs);
     if (!lfs->file_max) {
         lfs->file_max = LFS_FILE_MAX;
     }
 
-    LFS_ASSERT(lfs->cfg->attr_max <= LFS_ATTR_MAX);
-    lfs->attr_max = lfs->cfg->attr_max;
+    LFS_ASSERT(LFS_CFG_ATTR_MAX(lfs) <= LFS_ATTR_MAX);
+    lfs->attr_max = LFS_CFG_ATTR_MAX(lfs);
     if (!lfs->attr_max) {
         lfs->attr_max = LFS_ATTR_MAX;
     }
@@ -3568,51 +3643,34 @@ cleanup:
 
 static int lfs_deinit(lfs_t *lfs) {
     // free allocated memory
-    if (!lfs->cfg->read_buffer) {
+    if (!LFS_CFG_READ_BUFFER(lfs)) {
         lfs_free(lfs->rcache.buffer);
     }
 
-    if (!lfs->cfg->prog_buffer) {
+    if (!LFS_CFG_PROG_BUFFER(lfs)) {
         lfs_free(lfs->pcache.buffer);
     }
 
-    if (!lfs->cfg->lookahead_buffer) {
+    if (!LFS_CFG_LOOKAHEAD_BUFFER(lfs)) {
         lfs_free(lfs->free.buffer);
     }
 
     return 0;
 }
 
-int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_format(%p, %p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32", "
-                ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
-                ".lookahead_size=%"PRIu32", .read_buffer=%p, "
-                ".prog_buffer=%p, .lookahead_buffer=%p, "
-                ".name_max=%"PRIu32", .file_max=%"PRIu32", "
-                ".attr_max=%"PRIu32"})",
-            (void*)lfs, (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
-            cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
-            cfg->name_max, cfg->file_max, cfg->attr_max);
+static int lfs_formatcommon(lfs_t *lfs) {
     int err = 0;
     {
-        err = lfs_init(lfs, cfg);
+        err = lfs_initcommon(lfs);
         if (err) {
-            LFS_TRACE("lfs_format -> %d", err);
             return err;
         }
 
         // create free lookahead
-        memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
+        memset(lfs->free.buffer, 0, LFS_CFG_LOOKAHEAD_SIZE(lfs));
         lfs->free.off = 0;
-        lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size,
-                lfs->cfg->block_count);
+        lfs->free.size = lfs_min(8*LFS_CFG_LOOKAHEAD_SIZE(lfs),
+                LFS_CFG_BLOCK_COUNT(lfs));
         lfs->free.i = 0;
         lfs_alloc_ack(lfs);
 
@@ -3626,8 +3684,8 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
         // write one superblock
         lfs_superblock_t superblock = {
             .version     = LFS_DISK_VERSION,
-            .block_size  = lfs->cfg->block_size,
-            .block_count = lfs->cfg->block_count,
+            .block_size  = LFS_CFG_BLOCK_SIZE(lfs),
+            .block_count = LFS_CFG_BLOCK_COUNT(lfs),
             .name_max    = lfs->name_max,
             .file_max    = lfs->file_max,
             .attr_max    = lfs->attr_max,
@@ -3660,12 +3718,21 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
 
 cleanup:
     lfs_deinit(lfs);
-    LFS_TRACE("lfs_format -> %d", err);
     return err;
 }
 
-int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_mount(%p, %p {.context=%p, "
+#if defined(LFS_STATICCFG)
+int lfs_format(lfs_t *lfs) {
+    LFS_TRACE("lfs_format(%p)", (void*)lfs);
+    int err = lfs_formatcommon(lfs);
+    LFS_TRACE("lfs_format -> %d", err);
+    return err;
+}
+#endif
+
+#if !defined(LFS_STATICCFG)
+int lfs_formatcfg(lfs_t *lfs, const struct lfs_config *cfg) {
+    LFS_TRACE("lfs_formatcfg(%p, %p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32", "
@@ -3681,9 +3748,16 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
             cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
             cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
             cfg->name_max, cfg->file_max, cfg->attr_max);
-    int err = lfs_init(lfs, cfg);
+    lfs->cfg = cfg;
+    int err = lfs_formatcommon(lfs);
+    LFS_TRACE("lfs_formatcfg -> %d", err);
+    return err;
+}
+#endif
+
+static int lfs_mountcommon(lfs_t *lfs) {
+    int err = lfs_initcommon(lfs);
     if (err) {
-        LFS_TRACE("lfs_mount -> %d", err);
         return err;
     }
 
@@ -3691,7 +3765,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs_mdir_t dir = {.tail = {0, 1}};
     lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(dir.tail)) {
-        if (cycle >= lfs->cfg->block_count/2) {
+        if (cycle >= LFS_CFG_BLOCK_COUNT(lfs)/2) {
             // loop detected
             err = LFS_ERR_CORRUPT;
             goto cleanup;
@@ -3799,14 +3873,48 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
     // setup free lookahead
     lfs_alloc_reset(lfs);
 
-    LFS_TRACE("lfs_mount -> %d", 0);
+    LFS_TRACE("lfs_mountcfg -> %d", 0);
     return 0;
 
 cleanup:
     lfs_unmount(lfs);
+    LFS_TRACE("lfs_mountcfg -> %d", err);
+    return err;
+}
+
+#if defined(LFS_STATICCFG)
+int lfs_mount(lfs_t *lfs) {
+    LFS_TRACE("lfs_mount(%p)", (void*)lfs);
+    int err = lfs_mountcommon(lfs);
     LFS_TRACE("lfs_mount -> %d", err);
     return err;
 }
+#endif
+
+#if !defined(LFS_STATICCFG)
+int lfs_mountcfg(lfs_t *lfs, const struct lfs_config *cfg) {
+    LFS_TRACE("lfs_mountcfg(%p, %p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
+                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".block_size=%"PRIu32", .block_count=%"PRIu32", "
+                ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
+                ".lookahead_size=%"PRIu32", .read_buffer=%p, "
+                ".prog_buffer=%p, .lookahead_buffer=%p, "
+                ".name_max=%"PRIu32", .file_max=%"PRIu32", "
+                ".attr_max=%"PRIu32"})",
+            (void*)lfs, (void*)cfg, cfg->context,
+            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
+            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
+            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
+            cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
+            cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
+            cfg->name_max, cfg->file_max, cfg->attr_max);
+    lfs->cfg = cfg;
+    int err = lfs_mountcommon(lfs);
+    LFS_TRACE("lfs_mountcfg -> %d", err);
+    return err;
+}
+#endif
 
 int lfs_unmount(lfs_t *lfs) {
     LFS_TRACE("lfs_unmount(%p)", (void*)lfs);
@@ -3838,7 +3946,7 @@ int lfs_fs_traverseraw(lfs_t *lfs,
 
     lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(dir.tail)) {
-        if (cycle >= lfs->cfg->block_count/2) {
+        if (cycle >= LFS_CFG_BLOCK_COUNT(lfs)/2) {
             // loop detected
             return LFS_ERR_CORRUPT;
         }
@@ -3929,7 +4037,7 @@ static int lfs_fs_pred(lfs_t *lfs,
     pdir->tail[1] = 1;
     lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(pdir->tail)) {
-        if (cycle >= lfs->cfg->block_count/2) {
+        if (cycle >= LFS_CFG_BLOCK_COUNT(lfs)/2) {
             // loop detected
             return LFS_ERR_CORRUPT;
         }
@@ -3962,7 +4070,7 @@ static int lfs_fs_parent_match(void *data,
 
     lfs_block_t child[2];
     int err = lfs_bd_read(lfs,
-            &lfs->pcache, &lfs->rcache, lfs->cfg->block_size,
+            &lfs->pcache, &lfs->rcache, LFS_CFG_BLOCK_SIZE(lfs),
             disk->block, disk->off, &child, sizeof(child));
     if (err) {
         return err;
@@ -3979,7 +4087,7 @@ static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t pair[2],
     parent->tail[1] = 1;
     lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(parent->tail)) {
-        if (cycle >= lfs->cfg->block_count/2) {
+        if (cycle >= LFS_CFG_BLOCK_COUNT(lfs)/2) {
             // loop detected
             return LFS_ERR_CORRUPT;
         }
@@ -4421,7 +4529,7 @@ static int lfs1_dir_fetch(lfs_t *lfs,
         }
 
         if ((0x7fffffff & test.size) < sizeof(test)+4 ||
-            (0x7fffffff & test.size) > lfs->cfg->block_size) {
+            (0x7fffffff & test.size) > LFS_CFG_BLOCK_SIZE(lfs)) {
             continue;
         }
 
@@ -4600,11 +4708,10 @@ static int lfs1_moved(lfs_t *lfs, const void *e) {
 }
 
 /// Filesystem operations ///
-static int lfs1_mount(lfs_t *lfs, struct lfs1 *lfs1,
-        const struct lfs_config *cfg) {
+static int lfs1_mountcommon(lfs_t *lfs, struct lfs1 *lfs1) {
     int err = 0;
     {
-        err = lfs_init(lfs, cfg);
+        err = lfs_initcommont(lfs);
         if (err) {
             return err;
         }
@@ -4668,27 +4775,10 @@ static int lfs1_unmount(lfs_t *lfs) {
 }
 
 /// v1 migration ///
-int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_migrate(%p, %p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32", "
-                ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
-                ".lookahead_size=%"PRIu32", .read_buffer=%p, "
-                ".prog_buffer=%p, .lookahead_buffer=%p, "
-                ".name_max=%"PRIu32", .file_max=%"PRIu32", "
-                ".attr_max=%"PRIu32"})",
-            (void*)lfs, (void*)cfg, cfg->context,
-            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
-            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
-            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
-            cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
-            cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
-            cfg->name_max, cfg->file_max, cfg->attr_max);
+static int lfs_migratecommon(lfs_t *lfs) {
     struct lfs1 lfs1;
-    int err = lfs1_mount(lfs, &lfs1, cfg);
+    int err = lfs1_mountcommon(lfs, &lfs1);
     if (err) {
-        LFS_TRACE("lfs_migrate -> %d", err);
         return err;
     }
 
@@ -4872,8 +4962,8 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
         lfs_superblock_t superblock = {
             .version     = LFS_DISK_VERSION,
-            .block_size  = lfs->cfg->block_size,
-            .block_count = lfs->cfg->block_count,
+            .block_size  = LFS_CFG_BLOCK_SIZE(lfs),
+            .block_count = LFS_CFG_BLOCK_COUNT(lfs),
             .name_max    = lfs->name_max,
             .file_max    = lfs->file_max,
             .attr_max    = lfs->attr_max,
@@ -4905,8 +4995,41 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
 cleanup:
     lfs1_unmount(lfs);
-    LFS_TRACE("lfs_migrate -> %d", err);
     return err;
 }
 
+#if defined(LFS_STATICCFG)
+int lfs_migrate(lfs_t *lfs) {
+    LFS_TRACE("lfs_migrate(%p)", (void*)lfs);
+    int err = lfs_migratecommon(lfs);
+    LFS_TRACE("lfs_migrate -> %d", err);
+    return err;
+}
+#endif
+
+#if !defined(LFS_STATICCFG)
+int lfs_migratecfg(lfs_t *lfs, const struct lfs_config *cfg) {
+    LFS_TRACE("lfs_migratecfg(%p, %p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
+                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".block_size=%"PRIu32", .block_count=%"PRIu32", "
+                ".block_cycles=%"PRIu32", .cache_size=%"PRIu32", "
+                ".lookahead_size=%"PRIu32", .read_buffer=%p, "
+                ".prog_buffer=%p, .lookahead_buffer=%p, "
+                ".name_max=%"PRIu32", .file_max=%"PRIu32", "
+                ".attr_max=%"PRIu32"})",
+            (void*)lfs, (void*)cfg, cfg->context,
+            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
+            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
+            cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
+            cfg->block_cycles, cfg->cache_size, cfg->lookahead_size,
+            cfg->read_buffer, cfg->prog_buffer, cfg->lookahead_buffer,
+            cfg->name_max, cfg->file_max, cfg->attr_max);
+    lfs->cfg = cfg;
+    int err = lfs_migratecommon(lfs);
+    LFS_TRACE("lfs_migratecfg -> %d", err);
+    return err;
+}
+#endif
+
 #endif
diff --git a/lfs.h b/lfs.h
index 52e01b3..445c355 100644
--- a/lfs.h
+++ b/lfs.h
@@ -125,6 +125,7 @@ enum lfs_whence_flags {
 };
 
 
+#if !defined(LFS_STATICCFG)
 // Configuration provided during initialization of the littlefs
 struct lfs_config {
     // Opaque user provided context that can be used to pass
@@ -219,6 +220,99 @@ struct lfs_config {
     // LFS_ATTR_MAX when zero.
     lfs_size_t attr_max;
 };
+#else
+// Static configuration if LFS_STATICCFG is defined, there are defaults
+// for some of these, but some are required. For full documentation, see
+// the lfs_config struct above.
+
+// Block device operations
+int lfs_read(lfs_block_t block,
+        lfs_off_t off, void *buffer, lfs_size_t size);
+int lfs_prog(lfs_block_t block,
+        lfs_off_t off, const void *buffer, lfs_size_t size);
+int lfs_erase(lfs_block_t block);
+int lfs_sync(void);
+
+// Required configuration
+#ifndef LFS_READ_SIZE
+#error "LFS_STATICCFG requires LFS_READ_SIZE"
+#endif
+#ifndef LFS_PROG_SIZE
+#error "LFS_STATICCFG requires LFS_PROG_SIZE"
+#endif
+#ifndef LFS_BLOCK_SIZE
+#error "LFS_STATICCFG requires LFS_BLOCK_SIZE"
+#endif
+#ifndef LFS_BLOCK_COUNT
+#error "LFS_STATICCFG requires LFS_BLOCK_COUNT"
+#endif
+#ifndef LFS_BLOCK_CYCLES
+#error "LFS_STATICCFG requires LFS_BLOCK_CYCLES"
+#endif
+#ifndef LFS_CACHE_SIZE
+#error "LFS_STATICCFG requires LFS_CACHE_SIZE"
+#endif
+#ifndef LFS_LOOKAHEAD_SIZE
+#error "LFS_STATICCFG requires LFS_LOOKAHEAD_SIZE"
+#endif
+
+// Optional configuration
+#ifndef LFS_READ_BUFFER
+#define LFS_READ_BUFFER NULL
+#endif
+#ifndef LFS_PROG_BUFFER
+#define LFS_PROG_BUFFER NULL
+#endif
+#ifndef LFS_LOOKAHEAD_BUFFER
+#define LFS_LOOKAHEAD_BUFFER NULL
+#endif
+#ifndef LFS_NAME_MAX
+#define LFS_NAME_MAX 0
+#endif
+#ifndef LFS_FILE_MAX
+#define LFS_FILE_MAX 0
+#endif
+#ifndef LFS_ATTR_MAX
+#define LFS_ATTR_MAX 0
+#endif
+#endif
+
+#if !defined(LFS_FILE_STATICCFG)
+// Optional configuration provided during lfs_file_opencfg
+struct lfs_file_config {
+    // Optional statically allocated file buffer. Must be cache_size.
+    // By default lfs_malloc is used to allocate this buffer.
+    void *buffer;
+
+    // Optional list of custom attributes related to the file. If the file
+    // is opened with read access, these attributes will be read from disk
+    // during the open call. If the file is opened with write access, the
+    // attributes will be written to disk every file sync or close. This
+    // write occurs atomically with update to the file's contents.
+    //
+    // Custom attributes are uniquely identified by an 8-bit type and limited
+    // to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller
+    // than the buffer, it will be padded with zeros. If the stored attribute
+    // is larger, then it will be silently truncated. If the attribute is not
+    // found, it will be created implicitly.
+    struct lfs_attr *attrs;
+
+    // Number of custom attributes in the list
+    lfs_size_t attr_count;
+};
+#else
+// Static configuration if LFS_FILE_STATICCFG is defined. For full
+// documentation, see the lfs_file_config struct above.
+#ifndef LFS_FILE_BUFFER
+#define LFS_FILE_BUFFER NULL
+#endif
+#ifndef LFS_FILE_ATTRS
+#define LFS_FILE_ATTRS ((struct lfs_attr*)NULL)
+#endif
+#ifndef LFS_FILE_ATTR_COUNT
+#define LFS_FILE_ATTR_COUNT 0
+#endif
+#endif
 
 // File info structure
 struct lfs_info {
@@ -249,29 +343,6 @@ struct lfs_attr {
     lfs_size_t size;
 };
 
-// Optional configuration provided during lfs_file_opencfg
-struct lfs_file_config {
-    // Optional statically allocated file buffer. Must be cache_size.
-    // By default lfs_malloc is used to allocate this buffer.
-    void *buffer;
-
-    // Optional list of custom attributes related to the file. If the file
-    // is opened with read access, these attributes will be read from disk
-    // during the open call. If the file is opened with write access, the
-    // attributes will be written to disk every file sync or close. This
-    // write occurs atomically with update to the file's contents.
-    //
-    // Custom attributes are uniquely identified by an 8-bit type and limited
-    // to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller
-    // than the buffer, it will be padded with zeros. If the stored attribute
-    // is larger, then it will be silently truncated. If the attribute is not
-    // found, it will be created implicitly.
-    struct lfs_attr *attrs;
-
-    // Number of custom attributes in the list
-    lfs_size_t attr_count;
-};
-
 
 /// internal littlefs data structures ///
 typedef struct lfs_cache {
@@ -321,7 +392,9 @@ typedef struct lfs_file {
     lfs_off_t off;
     lfs_cache_t cache;
 
+#ifndef LFS_FILE_STATICCFG
     const struct lfs_file_config *cfg;
+#endif
 } lfs_file_t;
 
 typedef struct lfs_superblock {
@@ -364,7 +437,9 @@ typedef struct lfs {
         uint32_t *buffer;
     } free;
 
+#ifndef LFS_STATICCFG
     const struct lfs_config *cfg;
+#endif
     lfs_size_t name_max;
     lfs_size_t file_max;
     lfs_size_t attr_max;
@@ -377,16 +452,38 @@ typedef struct lfs {
 
 /// Filesystem functions ///
 
-// Format a block device with the littlefs
+#if defined(LFS_STATICCFG)
+// Format a block device with littlefs
+//
+// Requires a littlefs object. This clobbers the littlefs object, and does
+// not leave the filesystem mounted.
+//
+// Returns a negative error code on failure.
+int lfs_format(lfs_t *lfs);
+#endif
+
+#if !defined(LFS_STATICCFG)
+// Format a block device with littlefs with per-filesystem configuration
 //
 // Requires a littlefs object and config struct. This clobbers the littlefs
 // object, and does not leave the filesystem mounted. The config struct must
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int lfs_format(lfs_t *lfs, const struct lfs_config *config);
+int lfs_formatcfg(lfs_t *lfs, const struct lfs_config *config);
+#endif
 
-// Mounts a littlefs
+#if defined(LFS_STATICCFG)
+// Mounts littlefs
+//
+// Requires a littlefs object and static configuration.
+//
+// Returns a negative error code on failure.
+int lfs_mount(lfs_t *lfs);
+#endif
+
+#if !defined(LFS_STATICCFG)
+// Mounts a littlefs with per-filesystem configuration
 //
 // Requires a littlefs object and config struct. Multiple filesystems
 // may be mounted simultaneously with multiple littlefs objects. Both
@@ -394,7 +491,8 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *config);
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int lfs_mount(lfs_t *lfs, const struct lfs_config *config);
+int lfs_mountcfg(lfs_t *lfs, const struct lfs_config *config);
+#endif
 
 // Unmounts a littlefs
 //
@@ -468,7 +566,8 @@ int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
 int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags);
 
-// Open a file with extra configuration
+#if !defined(LFS_FILE_STATICCFG)
+// Open a file with per-file configuration
 //
 // The mode that the file is opened in is determined by the flags, which
 // are values from the enum lfs_open_flags that are bitwise-ored together.
@@ -481,6 +580,7 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
 int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags,
         const struct lfs_file_config *config);
+#endif
 
 // Close a file
 //
@@ -610,19 +710,34 @@ lfs_ssize_t lfs_fs_size(lfs_t *lfs);
 // Returns a negative error code on failure.
 int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 
-#ifdef LFS_MIGRATE
+#if defined(LFS_MIGRATE) && defined(LFS_STATICCFG)
 // Attempts to migrate a previous version of littlefs
 //
 // Behaves similarly to the lfs_format function. Attempts to mount
 // the previous version of littlefs and update the filesystem so it can be
 // mounted with the current version of littlefs.
 //
+// Requires a littlefs object. This clobbers the littlefs object, and does
+// not leave the filesystem mounted.
+//
+// Returns a negative error code on failure.
+int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
+#endif
+
+#if defined(LFS_MIGRATE) && !defined(LFS_STATICCFG)
+// Attempts to migrate a previous version of littlefs with per-filesystem
+// configuration
+//
+// Behaves similarly to the lfs_format function. Attempts to mount
+// the previous version of littlefs and update the filesystem so it can be
+// mounted with the current version of littlefs.
+//
 // Requires a littlefs object and config struct. This clobbers the littlefs
 // object, and does not leave the filesystem mounted. The config struct must
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
+int lfs_migratecfg(lfs_t *lfs, const struct lfs_config *cfg);
 #endif
 
 
diff --git a/tests/test_alloc.toml b/tests/test_alloc.toml
index fa92da5..711560f 100644
--- a/tests/test_alloc.toml
+++ b/tests/test_alloc.toml
@@ -9,12 +9,12 @@ code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
     lfs_file_t files[FILES];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "breakfast") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int n = 0; n < FILES; n++) {
         sprintf(path, "breakfast/%s", names[n]);
         lfs_file_open(&lfs, &files[n], path,
@@ -31,7 +31,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int n = 0; n < FILES; n++) {
         sprintf(path, "breakfast/%s", names[n]);
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
@@ -51,13 +51,13 @@ define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "breakfast") => 0;
     lfs_unmount(&lfs) => 0;
 
     for (int n = 0; n < FILES; n++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         sprintf(path, "breakfast/%s", names[n]);
         lfs_file_open(&lfs, &file, path,
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
@@ -70,7 +70,7 @@ code = '''
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int n = 0; n < FILES; n++) {
         sprintf(path, "breakfast/%s", names[n]);
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
@@ -92,14 +92,14 @@ code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
     lfs_file_t files[FILES];
 
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     for (int c = 0; c < CYCLES; c++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_mkdir(&lfs, "breakfast") => 0;
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int n = 0; n < FILES; n++) {
             sprintf(path, "breakfast/%s", names[n]);
             lfs_file_open(&lfs, &files[n], path,
@@ -116,7 +116,7 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int n = 0; n < FILES; n++) {
             sprintf(path, "breakfast/%s", names[n]);
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
@@ -129,7 +129,7 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int n = 0; n < FILES; n++) {
             sprintf(path, "breakfast/%s", names[n]);
             lfs_remove(&lfs, path) => 0;
@@ -146,15 +146,15 @@ define.CYCLES = [1, 10]
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
 
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     for (int c = 0; c < CYCLES; c++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_mkdir(&lfs, "breakfast") => 0;
         lfs_unmount(&lfs) => 0;
 
         for (int n = 0; n < FILES; n++) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mountcfg(&lfs, &cfg) => 0;
             sprintf(path, "breakfast/%s", names[n]);
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
@@ -167,7 +167,7 @@ code = '''
             lfs_unmount(&lfs) => 0;
         }
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int n = 0; n < FILES; n++) {
             sprintf(path, "breakfast/%s", names[n]);
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
@@ -180,7 +180,7 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int n = 0; n < FILES; n++) {
             sprintf(path, "breakfast/%s", names[n]);
             lfs_remove(&lfs, path) => 0;
@@ -192,8 +192,8 @@ code = '''
 
 [[case]] # exhaustion test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
     size = strlen("exhaustion");
     memcpy(buffer, "exhaustion", size);
@@ -216,7 +216,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
     size = strlen("exhaustion");
     lfs_file_size(&lfs, &file) => size;
@@ -229,8 +229,8 @@ code = '''
 [[case]] # exhaustion wraparound test
 define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / 3)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     lfs_file_open(&lfs, &file, "padding", LFS_O_WRONLY | LFS_O_CREAT);
     size = strlen("buffering");
@@ -263,7 +263,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "exhaustion", LFS_O_RDONLY);
     size = strlen("exhaustion");
     lfs_file_size(&lfs, &file) => size;
@@ -276,8 +276,8 @@ code = '''
 
 [[case]] # dir exhaustion test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // find out max file size
     lfs_mkdir(&lfs, "exhaustiondir") => 0;
@@ -328,8 +328,8 @@ in = "lfs.c"
 define.LFS_ERASE_CYCLES = 0xffffffff
 define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_READERROR'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     // first fill to exhaustion to find available space
     lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     strcpy((char*)buffer, "waka");
@@ -358,7 +358,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // remount to force an alloc scan
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // but mark the head of our file as a "bad block", this is force our
     // scan to bail early
@@ -393,7 +393,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // check that the disk isn't hurt
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "pacman", LFS_O_RDONLY) => 0;
     strcpy((char*)buffer, "waka");
     size = strlen("waka");
@@ -416,8 +416,8 @@ define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
 if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // find out max file size
     lfs_mkdir(&lfs, "exhaustiondir") => 0;
@@ -487,8 +487,8 @@ define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
 if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // create one block hole for half a directory
     lfs_file_open(&lfs, &file, "bump", LFS_O_WRONLY | LFS_O_CREAT) => 0;
@@ -510,7 +510,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // open hole
     lfs_remove(&lfs, "bump") => 0;
@@ -532,8 +532,8 @@ define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
 if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // fill completely with two files
     lfs_file_open(&lfs, &file, "exhaustion1",
@@ -560,7 +560,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // rewrite one file
     lfs_file_open(&lfs, &file, "exhaustion1",
@@ -597,8 +597,8 @@ define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
 if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // fill completely with two files
     lfs_file_open(&lfs, &file, "exhaustion1",
@@ -625,7 +625,7 @@ code = '''
 
     // remount to force reset of lookahead
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // rewrite one file with a hole of one block
     lfs_file_open(&lfs, &file, "exhaustion1",
diff --git a/tests/test_attrs.toml b/tests/test_attrs.toml
index db8d0c7..f57a491 100644
--- a/tests/test_attrs.toml
+++ b/tests/test_attrs.toml
@@ -1,14 +1,14 @@
 [[case]] # set/get attribute
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_setattr(&lfs, "hello", 'A', "aaaa",   4) => 0;
     lfs_setattr(&lfs, "hello", 'B', "bbbbbb", 6) => 0;
@@ -60,7 +60,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  9) => 9;
@@ -78,15 +78,15 @@ code = '''
 
 [[case]] # set/get root attribute
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_setattr(&lfs, "/", 'A', "aaaa",   4) => 0;
     lfs_setattr(&lfs, "/", 'B', "bbbbbb", 6) => 0;
@@ -137,7 +137,7 @@ code = '''
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  9) => 9;
@@ -155,15 +155,15 @@ code = '''
 
 [[case]] # set/get file attribute
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     struct lfs_attr attrs1[] = {
         {'A', buffer,    4},
@@ -238,7 +238,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(buffer, 0, sizeof(buffer));
     struct lfs_attr attrs3[] = {
         {'A', buffer,    4},
@@ -262,15 +262,15 @@ code = '''
 
 [[case]] # deferred file attributes
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_write(&lfs, &file, "hello", strlen("hello")) => strlen("hello");
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_setattr(&lfs, "hello/hello", 'B', "fffffffff",  9) => 0;
     lfs_setattr(&lfs, "hello/hello", 'C', "ccccc",      5) => 0;
 
diff --git a/tests/test_badblocks.toml b/tests/test_badblocks.toml
index 06967a6..2fed0f6 100644
--- a/tests/test_badblocks.toml
+++ b/tests/test_badblocks.toml
@@ -19,9 +19,9 @@ code = '''
         lfs_testbd_setwear(&cfg, badblock-1, 0) => 0;
         lfs_testbd_setwear(&cfg, badblock, 0xffffffff) => 0;
         
-        lfs_format(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int i = 1; i < 10; i++) {
             for (int j = 0; j < NAMEMULT; j++) {
                 buffer[j] = '0'+i;
@@ -46,7 +46,7 @@ code = '''
         }
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (int i = 1; i < 10; i++) {
             for (int j = 0; j < NAMEMULT; j++) {
                 buffer[j] = '0'+i;
@@ -93,9 +93,9 @@ code = '''
         lfs_testbd_setwear(&cfg, i+2, 0xffffffff) => 0;
     }
     
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
@@ -120,7 +120,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
@@ -166,9 +166,9 @@ code = '''
         lfs_testbd_setwear(&cfg, (2*i) + 2, 0xffffffff) => 0;
     }
     
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
@@ -193,7 +193,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < NAMEMULT; j++) {
             buffer[j] = '0'+i;
@@ -236,6 +236,6 @@ code = '''
     lfs_testbd_setwear(&cfg, 0, 0xffffffff) => 0;
     lfs_testbd_setwear(&cfg, 1, 0xffffffff) => 0;
 
-    lfs_format(&lfs, &cfg) => LFS_ERR_NOSPC;
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_formatcfg(&lfs, &cfg) => LFS_ERR_NOSPC;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
diff --git a/tests/test_dirs.toml b/tests/test_dirs.toml
index 270f4f8..218049a 100644
--- a/tests/test_dirs.toml
+++ b/tests/test_dirs.toml
@@ -1,7 +1,7 @@
 [[case]] # root
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -17,16 +17,16 @@ code = '''
 [[case]] # many directory creation
 define.N = 'range(0, 100, 3)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "dir%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -48,16 +48,16 @@ code = '''
 [[case]] # many directory removal
 define.N = 'range(3, 100, 11)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "removeme%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -75,14 +75,14 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "removeme%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -98,16 +98,16 @@ code = '''
 [[case]] # many directory rename
 define.N = 'range(3, 100, 11)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "test%03d", i);
         lfs_mkdir(&lfs, path) => 0;
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -125,7 +125,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         char oldpath[128];
         char newpath[128];
@@ -135,7 +135,7 @@ code = '''
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -158,10 +158,10 @@ code = '''
 define.N = [5, 11]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
@@ -237,9 +237,9 @@ code = '''
 [[case]] # file creation
 define.N = 'range(3, 100, 11)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "file%03d", i);
         lfs_file_open(&lfs, &file, path,
@@ -248,7 +248,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -270,9 +270,9 @@ code = '''
 [[case]] # file removal
 define.N = 'range(0, 100, 3)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "removeme%03d", i);
         lfs_file_open(&lfs, &file, path,
@@ -281,7 +281,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -299,14 +299,14 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "removeme%03d", i);
         lfs_remove(&lfs, path) => 0;
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -322,9 +322,9 @@ code = '''
 [[case]] # file rename
 define.N = 'range(0, 100, 3)'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "test%03d", i);
         lfs_file_open(&lfs, &file, path,
@@ -333,7 +333,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -351,7 +351,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         char oldpath[128];
         char newpath[128];
@@ -361,7 +361,7 @@ code = '''
     }
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -384,10 +384,10 @@ code = '''
 define.N = [5, 25]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
@@ -462,21 +462,21 @@ code = '''
 
 [[case]] # nested directories
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "potato") => 0;
     lfs_file_open(&lfs, &file, "burito",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "potato/baked") => 0;
     lfs_mkdir(&lfs, "potato/sweet") => 0;
     lfs_mkdir(&lfs, "potato/fried") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "potato") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -498,21 +498,21 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // try removing?
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "potato") => LFS_ERR_NOTEMPTY;
     lfs_unmount(&lfs) => 0;
 
     // try renaming?
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "potato", "coldpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "coldpotato", "warmpotato") => 0;
     lfs_rename(&lfs, "warmpotato", "hotpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "potato") => LFS_ERR_NOENT;
     lfs_remove(&lfs, "coldpotato") => LFS_ERR_NOENT;
     lfs_remove(&lfs, "warmpotato") => LFS_ERR_NOENT;
@@ -520,7 +520,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // try cross-directory renaming
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "coldpotato") => 0;
     lfs_rename(&lfs, "hotpotato/baked", "coldpotato/baked") => 0;
     lfs_rename(&lfs, "coldpotato", "hotpotato") => LFS_ERR_NOTEMPTY;
@@ -536,7 +536,7 @@ code = '''
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "hotpotato") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -558,7 +558,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
     
     // final remove
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
     lfs_remove(&lfs, "hotpotato/baked") => 0;
     lfs_remove(&lfs, "hotpotato") => LFS_ERR_NOTEMPTY;
@@ -568,7 +568,7 @@ code = '''
     lfs_remove(&lfs, "hotpotato") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -587,8 +587,8 @@ code = '''
 [[case]] # recursive remove
 define.N = [10, 100]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "prickly-pear") => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "prickly-pear/cactus%03d", i);
@@ -611,7 +611,7 @@ code = '''
     lfs_dir_close(&lfs, &dir) => 0;
     lfs_unmount(&lfs);
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOTEMPTY;
 
     lfs_dir_open(&lfs, &dir, "prickly-pear") => 0;
@@ -636,22 +636,22 @@ code = '''
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOENT;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "prickly-pear") => LFS_ERR_NOENT;
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # other error cases
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "potato") => 0;
     lfs_file_open(&lfs, &file, "burito",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     lfs_mkdir(&lfs, "potato") => LFS_ERR_EXIST;
     lfs_mkdir(&lfs, "burito") => LFS_ERR_EXIST;
@@ -696,7 +696,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // or on disk
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "/") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
@@ -718,8 +718,8 @@ code = '''
 [[case]] # directory seek
 define.COUNT = [4, 128, 132]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hello") => 0;
     for (int i = 0; i < COUNT; i++) {
         sprintf(path, "hello/kitty%03d", i);
@@ -728,7 +728,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     for (int j = 2; j < COUNT; j++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_dir_open(&lfs, &dir, "hello") => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
@@ -779,8 +779,8 @@ code = '''
 [[case]] # root seek
 define.COUNT = [4, 128, 132]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < COUNT; i++) {
         sprintf(path, "hi%03d", i);
         lfs_mkdir(&lfs, path) => 0;
@@ -788,7 +788,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     for (int j = 2; j < COUNT; j++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_dir_open(&lfs, &dir, "/") => 0;
         lfs_dir_read(&lfs, &dir, &info) => 1;
         assert(strcmp(info.name, ".") == 0);
diff --git a/tests/test_entries.toml b/tests/test_entries.toml
index 81e175f..c624559 100644
--- a/tests/test_entries.toml
+++ b/tests/test_entries.toml
@@ -10,8 +10,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 20
     sprintf(path, "hi0"); size = 20;
@@ -99,8 +99,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 20
     sprintf(path, "hi0"); size = 20;
@@ -188,8 +188,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 200
     sprintf(path, "hi0"); size = 200;
@@ -261,8 +261,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 200
     sprintf(path, "hi0"); size = 200;
@@ -350,8 +350,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 200
     sprintf(path, "hi0"); size = 200;
@@ -454,8 +454,8 @@ code = '''
     uint8_t wbuffer[1024];
     uint8_t rbuffer[1024];
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // write hi0 200
     sprintf(path, "hi0"); size = 200;
@@ -549,9 +549,9 @@ code = '''
 
 [[case]] # create too big
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(path, 'm', 200);
     path[200] = '\0';
 
@@ -574,9 +574,9 @@ code = '''
 
 [[case]] # resize too big
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     memset(path, 'm', 200);
     path[200] = '\0';
 
diff --git a/tests/test_evil.toml b/tests/test_evil.toml
index 920d3a0..c631799 100644
--- a/tests/test_evil.toml
+++ b/tests/test_evil.toml
@@ -9,10 +9,11 @@ define.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // change tail-pointer to invalid pointers
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
@@ -23,7 +24,7 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
 
 [[case]] # invalid dir pointer test
@@ -31,14 +32,15 @@ define.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // make a dir
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "dir_here") => 0;
     lfs_unmount(&lfs) => 0;
 
     // change the dir pointer to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our directory
@@ -57,7 +59,7 @@ code = '''
 
     // test that accessing our bad dir fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dir_here", &info) => 0;
     assert(strcmp(info.name, "dir_here") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -77,16 +79,17 @@ in = "lfs.c"
 define.SIZE = [10, 1000, 100000] # faked file size
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // make a file
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "file_here",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
     // change the file pointer to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our file
@@ -103,7 +106,7 @@ code = '''
 
     // test that accessing our bad file fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "file_here", &info) => 0;
     assert(strcmp(info.name, "file_here") == 0);
     assert(info.type == LFS_TYPE_REG);
@@ -125,9 +128,9 @@ define.SIZE = ['2*LFS_BLOCK_SIZE', '3*LFS_BLOCK_SIZE', '4*LFS_BLOCK_SIZE']
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // make a file
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "file_here",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
     for (int i = 0; i < SIZE; i++) {
@@ -137,7 +140,8 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
     // change pointer in CTZ skip-list to be invalid
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     // make sure id 1 == our file and get our CTZ structure
@@ -164,7 +168,7 @@ code = '''
 
     // test that accessing our bad file fails, note there's a number
     // of ways to access the dir, some can fail, but some don't
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "file_here", &info) => 0;
     assert(strcmp(info.name, "file_here") == 0);
     assert(info.type == LFS_TYPE_REG);
@@ -187,10 +191,11 @@ define.INVALSET = [0x3, 0x1, 0x2]
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // create an invalid gstate
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_fs_prepmove(&lfs, 1, (lfs_block_t [2]){
@@ -202,7 +207,7 @@ code = '''
     // test that mount fails gracefully
     // mount may not fail, but our first alloc should fail when
     // we try to fix the gstate
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "should_fail") => LFS_ERR_CORRUPT;
     lfs_unmount(&lfs) => 0;
 '''
@@ -213,10 +218,11 @@ code = '''
 in = "lfs.c"
 code = '''
     // create littlefs
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // change tail-pointer to point to ourself
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
@@ -225,20 +231,21 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
 
 [[case]] # metadata-pair threaded-list 2-length loop test
 in = "lfs.c"
 code = '''
     // create littlefs with child dir
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
     // find child
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_block_t pair[2];
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
@@ -255,20 +262,21 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
 
 [[case]] # metadata-pair threaded-list 1-length child loop test
 in = "lfs.c"
 code = '''
     // create littlefs with child dir
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
     // find child
-    lfs_init(&lfs, &cfg) => 0;
+    lfs.cfg = &cfg;
+    lfs_initcommon(&lfs) => 0;
     lfs_mdir_t mdir;
     lfs_block_t pair[2];
     lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
@@ -284,5 +292,5 @@ code = '''
     lfs_deinit(&lfs) => 0;
 
     // test that mount fails gracefully
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
diff --git a/tests/test_exhaustion.toml b/tests/test_exhaustion.toml
index 569611c..c339d45 100644
--- a/tests/test_exhaustion.toml
+++ b/tests/test_exhaustion.toml
@@ -11,14 +11,14 @@ define.LFS_BADBLOCK_BEHAVIOR = [
 ]
 define.FILES = 10
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "roadrunner") => 0;
     lfs_unmount(&lfs) => 0;
 
     uint32_t cycle = 0;
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
             sprintf(path, "roadrunner/test%d", i);
@@ -71,7 +71,7 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
         sprintf(path, "roadrunner/test%d", i);
@@ -96,11 +96,11 @@ define.LFS_BADBLOCK_BEHAVIOR = [
 ]
 define.FILES = 10
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     uint32_t cycle = 0;
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
             sprintf(path, "test%d", i);
@@ -153,7 +153,7 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
         sprintf(path, "test%d", i);
@@ -184,14 +184,14 @@ code = '''
                     (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
         }
 
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_mkdir(&lfs, "roadrunner") => 0;
         lfs_unmount(&lfs) => 0;
 
         uint32_t cycle = 0;
         while (true) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mountcfg(&lfs, &cfg) => 0;
             for (uint32_t i = 0; i < FILES; i++) {
                 // chose name, roughly random seed, and random 2^n size
                 sprintf(path, "roadrunner/test%d", i);
@@ -244,7 +244,7 @@ code = '''
 
 exhausted:
         // should still be readable
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
             sprintf(path, "roadrunner/test%d", i);
@@ -276,11 +276,11 @@ code = '''
                     (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
         }
 
-        lfs_format(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
 
         uint32_t cycle = 0;
         while (true) {
-            lfs_mount(&lfs, &cfg) => 0;
+            lfs_mountcfg(&lfs, &cfg) => 0;
             for (uint32_t i = 0; i < FILES; i++) {
                 // chose name, roughly random seed, and random 2^n size
                 sprintf(path, "test%d", i);
@@ -333,7 +333,7 @@ code = '''
 
 exhausted:
         // should still be readable
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // check for errors
             sprintf(path, "test%d", i);
@@ -358,14 +358,14 @@ define.CYCLES = 100
 define.FILES = 10
 if = 'LFS_BLOCK_CYCLES < CYCLES/10'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "roadrunner") => 0;
     lfs_unmount(&lfs) => 0;
 
     uint32_t cycle = 0;
     while (cycle < CYCLES) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
             sprintf(path, "roadrunner/test%d", i);
@@ -418,7 +418,7 @@ code = '''
 
 exhausted:
     // should still be readable
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (uint32_t i = 0; i < FILES; i++) {
         // check for errors
         sprintf(path, "roadrunner/test%d", i);
diff --git a/tests/test_files.toml b/tests/test_files.toml
index 565e665..eedcd96 100644
--- a/tests/test_files.toml
+++ b/tests/test_files.toml
@@ -1,8 +1,8 @@
 
 [[case]] # simple file test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "hello",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     size = strlen("Hello World!")+1;
@@ -11,7 +11,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "hello", LFS_O_RDONLY) => 0;
     lfs_file_read(&lfs, &file, buffer, size) => size;
     assert(strcmp((char*)buffer, "Hello World!") == 0);
@@ -23,10 +23,10 @@ code = '''
 define.SIZE = [32, 8192, 262144, 0, 7, 8193]
 define.CHUNKSIZE = [31, 16, 33, 1, 1023]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     srand(1);
@@ -41,7 +41,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE;
     srand(1);
@@ -62,10 +62,10 @@ define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
 define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
 define.CHUNKSIZE = [31, 16, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     srand(1);
@@ -80,7 +80,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
     srand(1);
@@ -96,7 +96,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // rewrite
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY) => 0;
     srand(2);
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
@@ -110,7 +110,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => lfs_max(SIZE1, SIZE2);
     srand(2);
@@ -144,10 +144,10 @@ define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
 define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
 define.CHUNKSIZE = [31, 16, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     srand(1);
@@ -162,7 +162,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
     srand(1);
@@ -178,7 +178,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // append
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY | LFS_O_APPEND) => 0;
     srand(2);
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
@@ -192,7 +192,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1 + SIZE2;
     srand(1);
@@ -221,10 +221,10 @@ define.SIZE1 = [32, 8192, 131072, 0, 7, 8193]
 define.SIZE2 = [32, 8192, 131072, 0, 7, 8193]
 define.CHUNKSIZE = [31, 16, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 
     // write
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     srand(1);
@@ -239,7 +239,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE1;
     srand(1);
@@ -255,7 +255,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // truncate
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_WRONLY | LFS_O_TRUNC) => 0;
     srand(2);
     for (lfs_size_t i = 0; i < SIZE2; i += CHUNKSIZE) {
@@ -269,7 +269,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // read
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => SIZE2;
     srand(2);
@@ -290,10 +290,10 @@ define.SIZE = [32, 0, 7, 2049]
 define.CHUNKSIZE = [31, 16, 65]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     err = lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY);
@@ -344,10 +344,10 @@ define = [
 ]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     err = lfs_file_open(&lfs, &file, "avacado", LFS_O_RDONLY);
@@ -406,9 +406,9 @@ code = '''
 [[case]] # many files
 define.N = 300
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // create N files of 7 bytes
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "file_%03d", i);
         lfs_file_open(&lfs, &file, path,
@@ -431,9 +431,9 @@ code = '''
 [[case]] # many files with power cycle
 define.N = 300
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // create N files of 7 bytes
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         sprintf(path, "file_%03d", i);
         lfs_file_open(&lfs, &file, path,
@@ -446,7 +446,7 @@ code = '''
         lfs_unmount(&lfs) => 0;
 
         char rbuffer[1024];
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
         lfs_file_read(&lfs, &file, rbuffer, size) => size;
         assert(strcmp(rbuffer, wbuffer) == 0);
@@ -459,10 +459,10 @@ code = '''
 define.N = 300
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     // create N files of 7 bytes
     for (int i = 0; i < N; i++) {
diff --git a/tests/test_interspersed.toml b/tests/test_interspersed.toml
index 87a0578..bf2027f 100644
--- a/tests/test_interspersed.toml
+++ b/tests/test_interspersed.toml
@@ -5,8 +5,8 @@ define.FILES = [4, 10, 26]
 code = '''
     lfs_file_t files[FILES];
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int j = 0; j < FILES; j++) {
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &files[j], path,
@@ -64,8 +64,8 @@ define.SIZE = [10, 100]
 define.FILES = [4, 10, 26]
 code = '''
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int j = 0; j < FILES; j++) {
         sprintf(path, "%c", alphas[j]);
         lfs_file_open(&lfs, &file, path,
@@ -77,7 +77,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "zzz", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     for (int j = 0; j < FILES; j++) {
         lfs_file_write(&lfs, &file, (const void*)"~", 1) => 1;
@@ -115,8 +115,8 @@ code = '''
 [[case]] # remove inconveniently test
 define.SIZE = [10, 100]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_t files[3];
     lfs_file_open(&lfs, &files[0], "e", LFS_O_WRONLY | LFS_O_CREAT) => 0;
     lfs_file_open(&lfs, &files[1], "f", LFS_O_WRONLY | LFS_O_CREAT) => 0;
@@ -180,10 +180,10 @@ code = '''
     lfs_file_t files[FILES];
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
 
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     for (int j = 0; j < FILES; j++) {
diff --git a/tests/test_move.toml b/tests/test_move.toml
index bb3b713..de62795 100644
--- a/tests/test_move.toml
+++ b/tests/test_move.toml
@@ -1,7 +1,7 @@
 [[case]] # move file
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -13,11 +13,11 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -57,8 +57,8 @@ code = '''
 
 [[case]] # noop move, yes this is legal
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "hi") => 0;
     lfs_rename(&lfs, "hi", "hi") => 0;
     lfs_mkdir(&lfs, "hi/hi") => 0;
@@ -74,8 +74,8 @@ code = '''
 [[case]] # move file corrupt source
 in = "lfs.c"
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -87,12 +87,12 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -108,7 +108,7 @@ code = '''
     cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
     cfg.sync(&cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -150,8 +150,8 @@ code = '''
 in = "lfs.c"
 if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -163,12 +163,12 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -185,7 +185,7 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -200,7 +200,7 @@ code = '''
     cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
     cfg.sync(&cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -242,8 +242,8 @@ code = '''
 in = "lfs.c"
 if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -255,12 +255,12 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -277,7 +277,7 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -293,11 +293,11 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // continue move
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -338,10 +338,10 @@ code = '''
 [[case]] # simple reentrant move file
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     err = lfs_mkdir(&lfs, "a");
     assert(!err || err == LFS_ERR_EXIST);
@@ -354,7 +354,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         // there should never exist _2_ hello files
         int count = 0;
         if (lfs_stat(&lfs, "a/hello", &info) == 0) {
@@ -384,7 +384,7 @@ code = '''
         assert(count <= 1);
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         if (lfs_stat(&lfs, "a/hello", &info) == 0 && info.size > 0) {
             lfs_rename(&lfs, "a/hello", "b/hello") => 0;
         } else if (lfs_stat(&lfs, "b/hello", &info) == 0) {
@@ -407,7 +407,7 @@ code = '''
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -447,8 +447,8 @@ code = '''
 
 [[case]] # move dir
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -459,11 +459,11 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -513,8 +513,8 @@ code = '''
 [[case]] # move dir corrupt source
 in = "lfs.c"
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -525,12 +525,12 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -546,7 +546,7 @@ code = '''
     cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
     cfg.sync(&cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -597,8 +597,8 @@ code = '''
 in = "lfs.c"
 if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -609,12 +609,12 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -631,7 +631,7 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -646,7 +646,7 @@ code = '''
     cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
     cfg.sync(&cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -697,8 +697,8 @@ code = '''
 in = "lfs.c"
 if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -709,12 +709,12 @@ code = '''
     lfs_mkdir(&lfs, "a/hi/ohayo") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
     // corrupt the source
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -731,7 +731,7 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // corrupt the destination
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "c") => 0;
     block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -747,11 +747,11 @@ code = '''
     cfg.sync(&cfg) => 0;
 
     // continue move
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hi", "c/hi") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -801,10 +801,10 @@ code = '''
 [[case]] # simple reentrant move dir
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     err = lfs_mkdir(&lfs, "a");
     assert(!err || err == LFS_ERR_EXIST);
@@ -817,7 +817,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     while (true) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         // there should never exist _2_ hi directories
         int count = 0;
         if (lfs_stat(&lfs, "a/hi", &info) == 0) {
@@ -843,7 +843,7 @@ code = '''
         assert(count <= 1);
         lfs_unmount(&lfs) => 0;
 
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         if (lfs_stat(&lfs, "a/hi", &info) == 0) {
             lfs_rename(&lfs, "a/hi", "b/hi") => 0;
         } else if (lfs_stat(&lfs, "b/hi", &info) == 0) {
@@ -868,7 +868,7 @@ code = '''
         lfs_unmount(&lfs) => 0;
     }
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "a") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(strcmp(info.name, ".") == 0);
@@ -917,8 +917,8 @@ code = '''
 
 [[case]] # move state stealing
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "a") => 0;
     lfs_mkdir(&lfs, "b") => 0;
     lfs_mkdir(&lfs, "c") => 0;
@@ -930,17 +930,17 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "a/hello", "b/hello") => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "b/hello", "c/hello") => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_rename(&lfs, "c/hello", "d/hello") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "a/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "b/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
     lfs_file_open(&lfs, &file, "c/hello", LFS_O_RDONLY) => LFS_ERR_NOENT;
@@ -954,12 +954,12 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_remove(&lfs, "b") => 0;
     lfs_remove(&lfs, "c") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "a", &info) => 0;
     lfs_stat(&lfs, "b", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "c", &info) => LFS_ERR_NOENT;
@@ -981,8 +981,8 @@ code = '''
 # Other specific corner cases
 [[case]] # create + delete in same commit with neighbors
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
     lfs_file_open(&lfs, &file, "/1.move_me",
@@ -1127,8 +1127,8 @@ code = '''
 # Other specific corner cases
 [[case]] # create + delete + delete in same commit with neighbors
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
     lfs_file_open(&lfs, &file, "/1.move_me",
@@ -1283,8 +1283,8 @@ code = '''
 
 [[case]] # create + delete in different dirs with neighbors
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     // littlefs keeps files sorted, so we know the order these will be in
     lfs_mkdir(&lfs, "/dir.1") => 0;
@@ -1523,8 +1523,8 @@ in = "lfs.c"
 define.RELOCATIONS = 'range(0x3+1)'
 define.LFS_ERASE_CYCLES = 0xffffffff
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     lfs_mkdir(&lfs, "/parent") => 0;
     lfs_mkdir(&lfs, "/parent/child") => 0;
@@ -1660,8 +1660,8 @@ in = "lfs.c"
 define.RELOCATIONS = 'range(0x7+1)'
 define.LFS_ERASE_CYCLES = 0xffffffff
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     lfs_mkdir(&lfs, "/parent") => 0;
     lfs_mkdir(&lfs, "/parent/child") => 0;
diff --git a/tests/test_orphans.toml b/tests/test_orphans.toml
index 241e273..e89f03c 100644
--- a/tests/test_orphans.toml
+++ b/tests/test_orphans.toml
@@ -2,8 +2,8 @@
 in = "lfs.c"
 if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "parent") => 0;
     lfs_mkdir(&lfs, "parent/orphan") => 0;
     lfs_mkdir(&lfs, "parent/child") => 0;
@@ -13,7 +13,7 @@ code = '''
     // corrupt the child's most recent commit, this should be the update
     // to the linked-list entry, which should orphan the orphan. Note this
     // makes a lot of assumptions about the remove operation.
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "parent/child") => 0;
     lfs_block_t block = dir.m.pair[0];
     lfs_dir_close(&lfs, &dir) => 0;
@@ -29,13 +29,13 @@ code = '''
     cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
     cfg.sync(&cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_fs_size(&lfs) => 8;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_fs_size(&lfs) => 8;
@@ -48,7 +48,7 @@ code = '''
     lfs_fs_size(&lfs) => 8;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "parent/child", &info) => 0;
     lfs_stat(&lfs, "parent/otherchild", &info) => 0;
@@ -66,10 +66,10 @@ define = [
     {FILES=3,  DEPTH=3, CYCLES=20},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     srand(1);
diff --git a/tests/test_paths.toml b/tests/test_paths.toml
index a7474c0..61f27b4 100644
--- a/tests/test_paths.toml
+++ b/tests/test_paths.toml
@@ -1,8 +1,8 @@
 
 [[case]] # simple path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -23,8 +23,8 @@ code = '''
 
 [[case]] # redundant slashes
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -47,8 +47,8 @@ code = '''
 
 [[case]] # dot path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -73,8 +73,8 @@ code = '''
 
 [[case]] # dot dot path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -103,8 +103,8 @@ code = '''
 
 [[case]] # trailing dot path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -125,8 +125,8 @@ code = '''
 
 [[case]] # leading dot path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, ".milk") => 0;
     lfs_stat(&lfs, ".milk", &info) => 0;
     strcmp(info.name, ".milk") => 0;
@@ -137,8 +137,8 @@ code = '''
 
 [[case]] # root dot dot path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "tea") => 0;
     lfs_mkdir(&lfs, "tea/hottea") => 0;
     lfs_mkdir(&lfs, "tea/warmtea") => 0;
@@ -161,8 +161,8 @@ code = '''
 
 [[case]] # invalid path tests
 code = '''
-    lfs_format(&lfs, &cfg);
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg);
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dirt", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "dirt/ground", &info) => LFS_ERR_NOENT;
     lfs_stat(&lfs, "dirt/ground/earth", &info) => LFS_ERR_NOENT;
@@ -182,8 +182,8 @@ code = '''
 
 [[case]] # root operations
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "/", &info) => 0;
     assert(strcmp(info.name, "/") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -198,8 +198,8 @@ code = '''
 
 [[case]] # root representations
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "/", &info) => 0;
     assert(strcmp(info.name, "/") == 0);
     assert(info.type == LFS_TYPE_DIR);
@@ -223,8 +223,8 @@ code = '''
 
 [[case]] # superblock conflict test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "littlefs", &info) => LFS_ERR_NOENT;
     lfs_remove(&lfs, "littlefs") => LFS_ERR_NOENT;
 
@@ -239,8 +239,8 @@ code = '''
 
 [[case]] # max path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "coffee") => 0;
     lfs_mkdir(&lfs, "coffee/hotcoffee") => 0;
     lfs_mkdir(&lfs, "coffee/warmcoffee") => 0;
@@ -263,8 +263,8 @@ code = '''
 
 [[case]] # really big path test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "coffee") => 0;
     lfs_mkdir(&lfs, "coffee/hotcoffee") => 0;
     lfs_mkdir(&lfs, "coffee/warmcoffee") => 0;
diff --git a/tests/test_relocations.toml b/tests/test_relocations.toml
index 71b1047..fb548dc 100644
--- a/tests/test_relocations.toml
+++ b/tests/test_relocations.toml
@@ -4,9 +4,9 @@ define.ITERATIONS = 20
 define.COUNT = 10
 define.LFS_BLOCK_CYCLES = [8, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // fill up filesystem so only ~16 blocks are left
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "padding", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     memset(buffer, 0, 512);
     while (LFS_BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
@@ -17,7 +17,7 @@ code = '''
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int j = 0; j < ITERATIONS; j++) {
         for (int i = 0; i < COUNT; i++) {
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
@@ -47,7 +47,7 @@ code = '''
     }
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_dir_open(&lfs, &dir, "child") => 0;
     lfs_dir_read(&lfs, &dir, &info) => 1;
     lfs_dir_read(&lfs, &dir, &info) => 1;
@@ -70,9 +70,9 @@ define.ITERATIONS = 20
 define.COUNT = 10
 define.LFS_BLOCK_CYCLES = [8, 1]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     // fill up filesystem so only ~16 blocks are left
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "padding", LFS_O_CREAT | LFS_O_WRONLY) => 0;
     memset(buffer, 0, 512);
     while (LFS_BLOCK_COUNT - lfs_fs_size(&lfs) > 16) {
@@ -83,7 +83,7 @@ code = '''
     lfs_mkdir(&lfs, "child") => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int j = 0; j < ITERATIONS; j++) {
         for (int i = 0; i < COUNT; i++) {
             sprintf(path, "child/test%03d_loooooooooooooooooong_name", i);
@@ -155,10 +155,10 @@ define = [
     {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     srand(1);
@@ -217,10 +217,10 @@ define = [
     {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
 ]
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     srand(1);
diff --git a/tests/test_seek.toml b/tests/test_seek.toml
index 79d7728..e0b0ea9 100644
--- a/tests/test_seek.toml
+++ b/tests/test_seek.toml
@@ -9,8 +9,8 @@ define = [
     {COUNT=4,   SKIP=2},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
     size = strlen("kittycatcat");
@@ -21,7 +21,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDONLY) => 0;
 
     lfs_soff_t pos = -1;
@@ -78,8 +78,8 @@ define = [
     {COUNT=4,   SKIP=2},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
     size = strlen("kittycatcat");
@@ -90,7 +90,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
 
     lfs_soff_t pos = -1;
@@ -133,8 +133,8 @@ code = '''
 define.COUNT = 132
 define.OFFSETS = '"{512, 1020, 513, 1021, 511, 1019, 1441}"'
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
     size = strlen("kittycatcat");
@@ -145,7 +145,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
 
     size = strlen("hedgehoghog");
@@ -193,8 +193,8 @@ define = [
     {COUNT=4,   SKIP=3},
 ]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
     size = strlen("kittycatcat");
@@ -204,7 +204,7 @@ code = '''
     }
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "kitty", LFS_O_RDWR) => 0;
 
     size = strlen("kittycatcat");
@@ -241,8 +241,8 @@ code = '''
 [[case]] # inline write and seek
 define.SIZE = [2, 4, 128, 132]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "tinykitty",
             LFS_O_RDWR | LFS_O_CREAT) => 0;
     int j = 0;
@@ -310,10 +310,10 @@ code = '''
 define.COUNT = [4, 64, 128]
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     err = lfs_file_open(&lfs, &file, "kitty", LFS_O_RDONLY);
     assert(!err || err == LFS_ERR_NOENT);
diff --git a/tests/test_superblocks.toml b/tests/test_superblocks.toml
index 407c845..6998810 100644
--- a/tests/test_superblocks.toml
+++ b/tests/test_superblocks.toml
@@ -1,37 +1,37 @@
 [[case]] # simple formatting test
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
 '''
 
 [[case]] # mount/unmount
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # reentrant format
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # invalid mount
 code = '''
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs_mountcfg(&lfs, &cfg) => LFS_ERR_CORRUPT;
 '''
 
 [[case]] # expanding superblock
 define.LFS_BLOCK_CYCLES = [32, 33, 1]
 define.N = [10, 100, 1000]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         lfs_file_open(&lfs, &file, "dummy",
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
@@ -44,7 +44,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "dummy",
             LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
     lfs_file_close(&lfs, &file) => 0;
@@ -58,9 +58,9 @@ code = '''
 define.LFS_BLOCK_CYCLES = [32, 33, 1]
 define.N = [10, 100, 1000]
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
         // remove lingering dummy?
         err = lfs_stat(&lfs, "dummy", &info);
         assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
@@ -80,7 +80,7 @@ code = '''
     }
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
     assert(info.type == LFS_TYPE_REG);
@@ -92,10 +92,10 @@ define.LFS_BLOCK_CYCLES = [2, 1]
 define.N = 24
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
 
     for (int i = 0; i < N; i++) {
@@ -119,7 +119,7 @@ code = '''
     lfs_unmount(&lfs) => 0;
 
     // one last check after power-cycle
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
     assert(info.type == LFS_TYPE_REG);
diff --git a/tests/test_truncate.toml b/tests/test_truncate.toml
index c11285b..38346e2 100644
--- a/tests/test_truncate.toml
+++ b/tests/test_truncate.toml
@@ -2,8 +2,8 @@
 define.MEDIUMSIZE = [32, 2048]
 define.LARGESIZE = 8192
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldynoop",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
@@ -17,7 +17,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
     
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
@@ -27,7 +27,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
@@ -46,8 +46,8 @@ code = '''
 define.MEDIUMSIZE = [32, 2048]
 define.LARGESIZE = 8192
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldyread",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
@@ -61,7 +61,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldyread", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
@@ -78,7 +78,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldyread", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
@@ -95,8 +95,8 @@ code = '''
 
 [[case]] # write, truncate, and read
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "sequence",
             LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
@@ -149,8 +149,8 @@ code = '''
 define.MEDIUMSIZE = [32, 2048]
 define.LARGESIZE = 8192
 code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldywrite",
             LFS_O_WRONLY | LFS_O_CREAT) => 0;
 
@@ -164,7 +164,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldywrite", LFS_O_RDWR) => 0;
     lfs_file_size(&lfs, &file) => LARGESIZE;
 
@@ -181,7 +181,7 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
     lfs_file_open(&lfs, &file, "baldywrite", LFS_O_RDONLY) => 0;
     lfs_file_size(&lfs, &file) => MEDIUMSIZE;
 
@@ -202,10 +202,10 @@ define.MEDIUMSIZE = [32, 1024]
 define.LARGESIZE = 2048
 reentrant = true
 code = '''
-    err = lfs_mount(&lfs, &cfg);
+    err = lfs_mountcfg(&lfs, &cfg);
     if (err) {
-        lfs_format(&lfs, &cfg) => 0;
-        lfs_mount(&lfs, &cfg) => 0;
+        lfs_formatcfg(&lfs, &cfg) => 0;
+        lfs_mountcfg(&lfs, &cfg) => 0;
     }
     err = lfs_file_open(&lfs, &file, "baldy", LFS_O_RDONLY);
     assert(!err || err == LFS_ERR_NOENT);
@@ -312,8 +312,8 @@ code = '''
     const lfs_off_t *hotsizes   = configs[CONFIG].hotsizes;
     const lfs_off_t *coldsizes  = configs[CONFIG].coldsizes;
 
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_formatcfg(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
         sprintf(path, "hairyhead%d", i);
@@ -340,7 +340,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
         sprintf(path, "hairyhead%d", i);
@@ -367,7 +367,7 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mountcfg(&lfs, &cfg) => 0;
 
     for (unsigned i = 0; i < COUNT; i++) {
         sprintf(path, "hairyhead%d", i);