Adopted erase_size/erase_count config in test block-devices/runners

In separating the configuration of littlefs from the physical geometry
of the underlying device, we can no longer rely solely on lfs_config to
contain all of the information necessary for the simulated block devices
we use for testing.

This adds a new lfs_*bd_config struct for each of the block devices, and
new erase_size/erase_count fields. The erase_* name was chosen since
these reflect the (simulated) physical erase size and count of
erase-sized blocks, unlike the block_* variants which represent logical
block sizes used for littlefs's bookkeeping.

It may be worth adopting erase_size/erase_count in littlefs's config at
some point in the future, but at the moment doesn't seem necessary.

Changing the lfs_bd_config structs to be required is probably a good
idea anyways, as it moves us more towards separating the bds from
littlefs. Though we can't quite get rid of the lfs_config parameter
because of the block-device API in lfs_config. Eventually it would be
nice to get rid of it, but that would require API breakage.

13 files changed, 248 insertions, 201 deletions

diff --git a/bd/lfs_emubd.c b/bd/lfs_emubd.c
index 546a90c..c27ae30 100644
--- a/bd/lfs_emubd.c
+++ b/bd/lfs_emubd.c
@@ -48,6 +48,7 @@ static void lfs_emubd_decblock(lfs_emubd_block_t *block) {
 static lfs_emubd_block_t *lfs_emubd_mutblock(
         const struct lfs_config *cfg,
         lfs_emubd_block_t **block) {
+    lfs_emubd_t *bd = cfg->context;
     lfs_emubd_block_t *block_ = *block;
     if (block_ && block_->rc == 1) {
         // rc == 1? can modify
@@ -56,13 +57,13 @@ static lfs_emubd_block_t *lfs_emubd_mutblock(
     } else if (block_) {
         // rc > 1? need to create a copy
         lfs_emubd_block_t *nblock = malloc(
-                sizeof(lfs_emubd_block_t) + cfg->block_size);
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
         if (!nblock) {
             return NULL;
         }
 
         memcpy(nblock, block_,
-                sizeof(lfs_emubd_block_t) + cfg->block_size);
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
         nblock->rc = 1;
 
         lfs_emubd_decblock(block_);
@@ -72,7 +73,7 @@ static lfs_emubd_block_t *lfs_emubd_mutblock(
     } else {
         // no block? need to allocate
         lfs_emubd_block_t *nblock = malloc(
-                sizeof(lfs_emubd_block_t) + cfg->block_size);
+                sizeof(lfs_emubd_block_t) + bd->cfg->erase_size);
         if (!nblock) {
             return NULL;
         }
@@ -81,10 +82,9 @@ static lfs_emubd_block_t *lfs_emubd_mutblock(
         nblock->wear = 0;
 
         // zero for consistency
-        lfs_emubd_t *bd = cfg->context;
         memset(nblock->data,
                 (bd->cfg->erase_value != -1) ? bd->cfg->erase_value : 0,
-                cfg->block_size);
+                bd->cfg->erase_size);
 
         *block = nblock;
         return nblock;
@@ -94,22 +94,22 @@ static lfs_emubd_block_t *lfs_emubd_mutblock(
 
 // emubd create/destroy
 
-int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
+int lfs_emubd_create(const struct lfs_config *cfg,
         const struct lfs_emubd_config *bdcfg) {
-    LFS_EMUBD_TRACE("lfs_emubd_createcfg(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\", "
-                "%p {.erase_value=%"PRId32", .erase_cycles=%"PRIu32", "
+    LFS_EMUBD_TRACE("lfs_emubd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32", "
+                ".erase_value=%"PRId32", .erase_cycles=%"PRIu32", "
                 ".badblock_behavior=%"PRIu8", .power_cycles=%"PRIu32", "
                 ".powerloss_behavior=%"PRIu8", .powerloss_cb=%p, "
                 ".powerloss_data=%p, .track_branches=%d})",
             (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,
-            path, (void*)bdcfg, bdcfg->erase_value, bdcfg->erase_cycles,
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count, bdcfg->erase_value, bdcfg->erase_cycles,
             bdcfg->badblock_behavior, bdcfg->power_cycles,
             bdcfg->powerloss_behavior, (void*)(uintptr_t)bdcfg->powerloss_cb,
             bdcfg->powerloss_data, bdcfg->track_branches);
@@ -117,12 +117,12 @@ int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
     bd->cfg = bdcfg;
 
     // allocate our block array, all blocks start as uninitialized
-    bd->blocks = malloc(cfg->block_count * sizeof(lfs_emubd_block_t*));
+    bd->blocks = malloc(bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
     if (!bd->blocks) {
-        LFS_EMUBD_TRACE("lfs_emubd_createcfg -> %d", LFS_ERR_NOMEM);
+        LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
         return LFS_ERR_NOMEM;
     }
-    memset(bd->blocks, 0, cfg->block_count * sizeof(lfs_emubd_block_t*));
+    memset(bd->blocks, 0, bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
 
     // setup testing things
     bd->readed = 0;
@@ -134,7 +134,7 @@ int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
     if (bd->cfg->disk_path) {
         bd->disk = malloc(sizeof(lfs_emubd_disk_t));
         if (!bd->disk) {
-            LFS_EMUBD_TRACE("lfs_emubd_createcfg -> %d", LFS_ERR_NOMEM);
+            LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
         }
         bd->disk->rc = 1;
@@ -156,21 +156,21 @@ int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
         // if we're emulating erase values, we can keep a block around in
         // memory of just the erase state to speed up emulated erases
         if (bd->cfg->erase_value != -1) {
-            bd->disk->scratch = malloc(cfg->block_size);
+            bd->disk->scratch = malloc(bd->cfg->erase_size);
             if (!bd->disk->scratch) {
-                LFS_EMUBD_TRACE("lfs_emubd_createcfg -> %d", LFS_ERR_NOMEM);
+                LFS_EMUBD_TRACE("lfs_emubd_create -> %d", LFS_ERR_NOMEM);
                 return LFS_ERR_NOMEM;
             }
             memset(bd->disk->scratch,
                     bd->cfg->erase_value,
-                    cfg->block_size);
+                    bd->cfg->erase_size);
 
             // go ahead and erase all of the disk, otherwise the file will not
             // match our internal representation
-            for (size_t i = 0; i < cfg->block_count; i++) {
+            for (size_t i = 0; i < bd->cfg->erase_count; i++) {
                 ssize_t res = write(bd->disk->fd,
                         bd->disk->scratch,
-                        cfg->block_size);
+                        bd->cfg->erase_size);
                 if (res < 0) {
                     int err = -errno;
                     LFS_EMUBD_TRACE("lfs_emubd_create -> %d", err);
@@ -180,33 +180,16 @@ int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
         }
     }
 
-    LFS_EMUBD_TRACE("lfs_emubd_createcfg -> %d", 0);
+    LFS_EMUBD_TRACE("lfs_emubd_create -> %d", 0);
     return 0;
 }
 
-int lfs_emubd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_EMUBD_TRACE("lfs_emubd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\")",
-            (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,
-            path);
-    static const struct lfs_emubd_config defaults = {.erase_value=-1};
-    int err = lfs_emubd_createcfg(cfg, path, &defaults);
-    LFS_EMUBD_TRACE("lfs_emubd_create -> %d", err);
-    return err;
-}
-
 int lfs_emubd_destroy(const struct lfs_config *cfg) {
     LFS_EMUBD_TRACE("lfs_emubd_destroy(%p)", (void*)cfg);
     lfs_emubd_t *bd = cfg->context;
 
     // decrement reference counts
-    for (lfs_block_t i = 0; i < cfg->block_count; i++) {
+    for (lfs_block_t i = 0; i < bd->cfg->erase_count; i++) {
         lfs_emubd_decblock(bd->blocks[i]);
     }
     free(bd->blocks);
@@ -237,10 +220,10 @@ int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
     lfs_emubd_t *bd = cfg->context;
 
     // check if read is valid
-    LFS_ASSERT(!cfg->block_count || block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // get the block
     const lfs_emubd_block_t *b = bd->blocks[block];
@@ -287,10 +270,10 @@ int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
     lfs_emubd_t *bd = cfg->context;
 
     // check if write is valid
-    LFS_ASSERT(!cfg->block_count || block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // get the block
     lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
@@ -327,7 +310,7 @@ int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
     // mirror to disk file?
     if (bd->disk) {
         off_t res1 = lseek(bd->disk->fd,
-                (off_t)block*cfg->block_size + (off_t)off,
+                (off_t)block*bd->cfg->erase_size + (off_t)off,
                 SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
@@ -372,11 +355,11 @@ int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
 
 int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     LFS_EMUBD_TRACE("lfs_emubd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
-            (void*)cfg, block, cfg->block_size);
+            (void*)cfg, block, ((lfs_emubd_t*)cfg->context)->cfg->erase_size);
     lfs_emubd_t *bd = cfg->context;
 
     // check if erase is valid
-    LFS_ASSERT(!cfg->block_count || block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // get the block
     lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
@@ -405,12 +388,12 @@ int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
 
     // emulate an erase value?
     if (bd->cfg->erase_value != -1) {
-        memset(b->data, bd->cfg->erase_value, cfg->block_size);
+        memset(b->data, bd->cfg->erase_value, bd->cfg->erase_size);
 
         // mirror to disk file?
         if (bd->disk) {
             off_t res1 = lseek(bd->disk->fd,
-                    (off_t)block*cfg->block_size,
+                    (off_t)block*bd->cfg->erase_size,
                     SEEK_SET);
             if (res1 < 0) {
                 int err = -errno;
@@ -420,7 +403,7 @@ int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
 
             ssize_t res2 = write(bd->disk->fd,
                     bd->disk->scratch,
-                    cfg->block_size);
+                    bd->cfg->erase_size);
             if (res2 < 0) {
                 int err = -errno;
                 LFS_EMUBD_TRACE("lfs_emubd_erase -> %d", err);
@@ -430,7 +413,7 @@ int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     }
 
     // track erases
-    bd->erased += cfg->block_size;
+    bd->erased += bd->cfg->erase_size;
     if (bd->cfg->erase_sleep) {
         int err = nanosleep(&(struct timespec){
                 .tv_sec=bd->cfg->erase_sleep/1000000000,
@@ -573,7 +556,7 @@ lfs_emubd_swear_t lfs_emubd_wear(const struct lfs_config *cfg,
     lfs_emubd_t *bd = cfg->context;
 
     // check if block is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // get the wear
     lfs_emubd_wear_t wear;
@@ -595,7 +578,7 @@ int lfs_emubd_setwear(const struct lfs_config *cfg,
     lfs_emubd_t *bd = cfg->context;
 
     // check if block is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // set the wear
     lfs_emubd_block_t *b = lfs_emubd_mutblock(cfg, &bd->blocks[block]);
@@ -635,13 +618,13 @@ int lfs_emubd_copy(const struct lfs_config *cfg, lfs_emubd_t *copy) {
     lfs_emubd_t *bd = cfg->context;
 
     // lazily copy over our block array
-    copy->blocks = malloc(cfg->block_count * sizeof(lfs_emubd_block_t*));
+    copy->blocks = malloc(bd->cfg->erase_count * sizeof(lfs_emubd_block_t*));
     if (!copy->blocks) {
         LFS_EMUBD_TRACE("lfs_emubd_copy -> %d", LFS_ERR_NOMEM);
         return LFS_ERR_NOMEM;
     }
 
-    for (size_t i = 0; i < cfg->block_count; i++) {
+    for (size_t i = 0; i < bd->cfg->erase_count; i++) {
         copy->blocks[i] = lfs_emubd_incblock(bd->blocks[i]);
     }
 
diff --git a/bd/lfs_emubd.h b/bd/lfs_emubd.h
index 35a411f..9049649 100644
--- a/bd/lfs_emubd.h
+++ b/bd/lfs_emubd.h
@@ -67,6 +67,18 @@ typedef int64_t lfs_emubd_ssleep_t;
 
 // emubd config, this is required for testing
 struct lfs_emubd_config {
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
+
     // 8-bit erase value to use for simulating erases. -1 does not simulate
     // erases, which can speed up testing by avoiding the extra block-device
     // operations to store the erase value.
@@ -149,11 +161,7 @@ typedef struct lfs_emubd {
 /// Block device API ///
 
 // Create an emulating block device using the geometry in lfs_config
-//
-// Note that filebd is used if a path is provided, if path is NULL
-// emubd will use rambd which can be much faster.
-int lfs_emubd_create(const struct lfs_config *cfg, const char *path);
-int lfs_emubd_createcfg(const struct lfs_config *cfg, const char *path,
+int lfs_emubd_create(const struct lfs_config *cfg,
         const struct lfs_emubd_config *bdcfg);
 
 // Clean up memory associated with block device
diff --git a/bd/lfs_filebd.c b/bd/lfs_filebd.c
index 780c8f9..4ff25d4 100644
--- a/bd/lfs_filebd.c
+++ b/bd/lfs_filebd.c
@@ -15,18 +15,22 @@
 #include <windows.h>
 #endif
 
-int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
+int lfs_filebd_create(const struct lfs_config *cfg, const char *path,
+        const struct lfs_filebd_config *bdcfg) {
     LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "\"%s\")",
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "\"%s\", "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32"})",
             (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,
-            path, (void*)bdcfg, bdcfg->erase_value);
+            path,
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count);
     lfs_filebd_t *bd = cfg->context;
+    bd->cfg = bdcfg;
 
     // open file
     #ifdef _WIN32
@@ -66,17 +70,17 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
     lfs_filebd_t *bd = cfg->context;
 
     // check if read is valid
-    LFS_ASSERT(block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // zero for reproducibility (in case file is truncated)
     memset(buffer, 0, size);
 
     // read
     off_t res1 = lseek(bd->fd,
-            (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
@@ -102,14 +106,14 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
     lfs_filebd_t *bd = cfg->context;
 
     // check if write is valid
-    LFS_ASSERT(block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // program data
     off_t res1 = lseek(bd->fd,
-            (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
         LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
@@ -129,10 +133,11 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
 
 int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
-            (void*)cfg, block, cfg->block_size);
+            (void*)cfg, block, ((lfs_file_t*)cfg->context)->cfg->erase_size);
+    lfs_filebd_t *bd = cfg->context;
 
     // check if erase is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // erase is a noop
     (void)block;
diff --git a/bd/lfs_filebd.h b/bd/lfs_filebd.h
index 0f24996..d7d2fd9 100644
--- a/bd/lfs_filebd.h
+++ b/bd/lfs_filebd.h
@@ -26,14 +26,31 @@ extern "C"
 #endif
 #endif
 
+// filebd config
+struct lfs_filebd_config {
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
+};
+
 // filebd state
 typedef struct lfs_filebd {
     int fd;
+    const struct lfs_filebd_config *cfg;
 } lfs_filebd_t;
 
 
-// Create a file block device using the geometry in lfs_config
-int lfs_filebd_create(const struct lfs_config *cfg, const char *path);
+// Create a file block device
+int lfs_filebd_create(const struct lfs_config *cfg, const char *path,
+        const struct lfs_filebd_config *bdcfg);
 
 // Clean up memory associated with block device
 int lfs_filebd_destroy(const struct lfs_config *cfg);
diff --git a/bd/lfs_rambd.c b/bd/lfs_rambd.c
index ab180b9..a6a0572 100644
--- a/bd/lfs_rambd.c
+++ b/bd/lfs_rambd.c
@@ -7,18 +7,19 @@
  */
 #include "bd/lfs_rambd.h"
 
-int lfs_rambd_createcfg(const struct lfs_config *cfg,
+int lfs_rambd_create(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg) {
-    LFS_RAMBD_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
-                "%p {.buffer=%p})",
+    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32", "
+                ".buffer=%p})",
             (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,
-            (void*)bdcfg, bdcfg->buffer);
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count, bdcfg->buffer);
     lfs_rambd_t *bd = cfg->context;
     bd->cfg = bdcfg;
 
@@ -26,35 +27,20 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
     if (bd->cfg->buffer) {
         bd->buffer = bd->cfg->buffer;
     } else {
-        bd->buffer = lfs_malloc(cfg->block_size * cfg->block_count);
+        bd->buffer = lfs_malloc(bd->cfg->erase_size * bd->cfg->erase_count);
         if (!bd->buffer) {
-            LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
+            LFS_RAMBD_TRACE("lfs_rambd_create -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
         }
     }
 
     // zero for reproducibility
-    memset(bd->buffer, 0, cfg->block_size * cfg->block_count);
+    memset(bd->buffer, 0, bd->cfg->erase_size * bd->cfg->erase_count);
 
-    LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", 0);
     return 0;
 }
 
-int lfs_rambd_create(const struct lfs_config *cfg) {
-    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
-                ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
-                ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
-                ".block_size=%"PRIu32", .block_count=%"PRIu32"})",
-            (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);
-    static const struct lfs_rambd_config defaults = {0};
-    int err = lfs_rambd_createcfg(cfg, &defaults);
-    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", err);
-    return err;
-}
-
 int lfs_rambd_destroy(const struct lfs_config *cfg) {
     LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
     // clean up memory
@@ -74,13 +60,13 @@ int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
     lfs_rambd_t *bd = cfg->context;
 
     // check if read is valid
-    LFS_ASSERT(block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->read_size == 0);
-    LFS_ASSERT(size % cfg->read_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // read data
-    memcpy(buffer, &bd->buffer[block*cfg->block_size + off], size);
+    memcpy(buffer, &bd->buffer[block*bd->cfg->erase_size + off], size);
 
     LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
     return 0;
@@ -94,13 +80,13 @@ int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
     lfs_rambd_t *bd = cfg->context;
 
     // check if write is valid
-    LFS_ASSERT(block < cfg->block_count);
-    LFS_ASSERT(off  % cfg->prog_size == 0);
-    LFS_ASSERT(size % cfg->prog_size == 0);
-    LFS_ASSERT(off+size <= cfg->block_size);
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
 
     // program data
-    memcpy(&bd->buffer[block*cfg->block_size + off], buffer, size);
+    memcpy(&bd->buffer[block*bd->cfg->erase_size + off], buffer, size);
 
     LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
     return 0;
@@ -108,10 +94,11 @@ int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
 
 int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
-            (void*)cfg, block, cfg->block_size);
+            (void*)cfg, block, ((lfs_rambd_t*)cfg->context)->cfg->erase_size);
+    lfs_rambd_t *bd = cfg->context;
 
     // check if erase is valid
-    LFS_ASSERT(block < cfg->block_count);
+    LFS_ASSERT(block < bd->cfg->erase_count);
 
     // erase is a noop
     (void)block;
diff --git a/bd/lfs_rambd.h b/bd/lfs_rambd.h
index 3424680..8663702 100644
--- a/bd/lfs_rambd.h
+++ b/bd/lfs_rambd.h
@@ -26,8 +26,20 @@ extern "C"
 #endif
 #endif
 
-// rambd config (optional)
+// rambd config
 struct lfs_rambd_config {
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
+
     // Optional statically allocated buffer for the block device.
     void *buffer;
 };
@@ -39,9 +51,8 @@ typedef struct lfs_rambd {
 } lfs_rambd_t;
 
 
-// Create a RAM block device using the geometry in lfs_config
-int lfs_rambd_create(const struct lfs_config *cfg);
-int lfs_rambd_createcfg(const struct lfs_config *cfg,
+// Create a RAM block device
+int lfs_rambd_create(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg);
 
 // Clean up memory associated with block device
diff --git a/runners/bench_runner.c b/runners/bench_runner.c
index ba791b2..f4dce22 100644
--- a/runners/bench_runner.c
+++ b/runners/bench_runner.c
@@ -1271,9 +1271,9 @@ static void list_geometries(void) {
                 builtin_geometries[g].name,
                 READ_SIZE,
                 PROG_SIZE,
-                BLOCK_SIZE,
-                BLOCK_COUNT,
-                BLOCK_SIZE*BLOCK_COUNT);
+                ERASE_SIZE,
+                ERASE_COUNT,
+                ERASE_SIZE*ERASE_COUNT);
     }
 }
 
@@ -1324,6 +1324,10 @@ void perm_run(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1333,7 +1337,7 @@ void perm_run(
         .erase_sleep        = bench_erase_sleep,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, bench_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -1761,19 +1765,19 @@ invalid_define:
                                     = BENCH_LIT(sizes[0]);
                             geometry->defines[PROG_SIZE_i]
                                     = BENCH_LIT(sizes[1]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[2]);
                         } else if (count >= 2) {
                             geometry->defines[PROG_SIZE_i]
                                     = BENCH_LIT(sizes[0]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[1]);
                         } else {
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[0]);
                         }
                         if (count >= 4) {
-                            geometry->defines[BLOCK_COUNT_i]
+                            geometry->defines[ERASE_COUNT_i]
                                     = BENCH_LIT(sizes[3]);
                         }
                         optarg = s;
@@ -1805,19 +1809,19 @@ invalid_define:
                                     = BENCH_LIT(sizes[0]);
                             geometry->defines[PROG_SIZE_i]
                                     = BENCH_LIT(sizes[1]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[2]);
                         } else if (count >= 2) {
                             geometry->defines[PROG_SIZE_i]
                                     = BENCH_LIT(sizes[0]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[1]);
                         } else {
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = BENCH_LIT(sizes[0]);
                         }
                         if (count >= 4) {
-                            geometry->defines[BLOCK_COUNT_i]
+                            geometry->defines[ERASE_COUNT_i]
                                     = BENCH_LIT(sizes[3]);
                         }
                         optarg = s;
diff --git a/runners/bench_runner.h b/runners/bench_runner.h
index 6296c09..b072970 100644
--- a/runners/bench_runner.h
+++ b/runners/bench_runner.h
@@ -89,18 +89,22 @@ intmax_t bench_define(size_t define);
  
 #define READ_SIZE_i          0
 #define PROG_SIZE_i          1
-#define BLOCK_SIZE_i         2
-#define BLOCK_COUNT_i        3
-#define CACHE_SIZE_i         4
-#define LOOKAHEAD_SIZE_i     5
-#define BLOCK_CYCLES_i       6
-#define ERASE_VALUE_i        7
-#define ERASE_CYCLES_i       8
-#define BADBLOCK_BEHAVIOR_i  9
-#define POWERLOSS_BEHAVIOR_i 10
+#define ERASE_SIZE_i         2
+#define ERASE_COUNT_i        3
+#define BLOCK_SIZE_i         4
+#define BLOCK_COUNT_i        5
+#define CACHE_SIZE_i         6
+#define LOOKAHEAD_SIZE_i     7
+#define BLOCK_CYCLES_i       8
+#define ERASE_VALUE_i        9
+#define ERASE_CYCLES_i       10
+#define BADBLOCK_BEHAVIOR_i  11
+#define POWERLOSS_BEHAVIOR_i 12
 
 #define READ_SIZE           bench_define(READ_SIZE_i)
 #define PROG_SIZE           bench_define(PROG_SIZE_i)
+#define ERASE_SIZE          bench_define(ERASE_SIZE_i)
+#define ERASE_COUNT         bench_define(ERASE_COUNT_i)
 #define BLOCK_SIZE          bench_define(BLOCK_SIZE_i)
 #define BLOCK_COUNT         bench_define(BLOCK_COUNT_i)
 #define CACHE_SIZE          bench_define(CACHE_SIZE_i)
@@ -113,9 +117,11 @@ intmax_t bench_define(size_t define);
 
 #define BENCH_IMPLICIT_DEFINES \
     BENCH_DEF(READ_SIZE,          PROG_SIZE) \
-    BENCH_DEF(PROG_SIZE,          BLOCK_SIZE) \
-    BENCH_DEF(BLOCK_SIZE,         0) \
-    BENCH_DEF(BLOCK_COUNT,        (1024*1024)/BLOCK_SIZE) \
+    BENCH_DEF(PROG_SIZE,          ERASE_SIZE) \
+    BENCH_DEF(ERASE_SIZE,         0) \
+    BENCH_DEF(ERASE_COUNT,        (1024*1024)/BLOCK_SIZE) \
+    BENCH_DEF(BLOCK_SIZE,         ERASE_SIZE) \
+    BENCH_DEF(BLOCK_COUNT,        ERASE_COUNT/lfs_max(BLOCK_SIZE/ERASE_SIZE,1))\
     BENCH_DEF(CACHE_SIZE,         lfs_max(64,lfs_max(READ_SIZE,PROG_SIZE))) \
     BENCH_DEF(LOOKAHEAD_SIZE,     16) \
     BENCH_DEF(BLOCK_CYCLES,       -1) \
@@ -125,7 +131,7 @@ intmax_t bench_define(size_t define);
     BENCH_DEF(POWERLOSS_BEHAVIOR, LFS_EMUBD_POWERLOSS_NOOP)
 
 #define BENCH_GEOMETRY_DEFINE_COUNT 4
-#define BENCH_IMPLICIT_DEFINE_COUNT 11
+#define BENCH_IMPLICIT_DEFINE_COUNT 13
 
 
 #endif
diff --git a/runners/test_runner.c b/runners/test_runner.c
index 27f8524..13befdc 100644
--- a/runners/test_runner.c
+++ b/runners/test_runner.c
@@ -1312,9 +1312,9 @@ static void list_geometries(void) {
                 builtin_geometries[g].name,
                 READ_SIZE,
                 PROG_SIZE,
-                BLOCK_SIZE,
-                BLOCK_COUNT,
-                BLOCK_SIZE*BLOCK_COUNT);
+                ERASE_SIZE,
+                ERASE_COUNT,
+                ERASE_SIZE*ERASE_COUNT);
     }
 }
 
@@ -1352,6 +1352,10 @@ static void run_powerloss_none(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1361,7 +1365,7 @@ static void run_powerloss_none(
         .erase_sleep        = test_erase_sleep,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, test_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -1424,6 +1428,10 @@ static void run_powerloss_linear(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1437,7 +1445,7 @@ static void run_powerloss_linear(
         .powerloss_data     = &powerloss_jmp,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, test_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -1513,6 +1521,10 @@ static void run_powerloss_log(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1526,7 +1538,7 @@ static void run_powerloss_log(
         .powerloss_data     = &powerloss_jmp,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, test_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -1600,6 +1612,10 @@ static void run_powerloss_cycles(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1613,7 +1629,7 @@ static void run_powerloss_cycles(
         .powerloss_data     = &powerloss_jmp,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, test_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -1785,6 +1801,10 @@ static void run_powerloss_exhaustive(
     };
 
     struct lfs_emubd_config bdcfg = {
+        .read_size          = READ_SIZE,
+        .prog_size          = PROG_SIZE,
+        .erase_size         = ERASE_SIZE,
+        .erase_count        = ERASE_COUNT,
         .erase_value        = ERASE_VALUE,
         .erase_cycles       = ERASE_CYCLES,
         .badblock_behavior  = BADBLOCK_BEHAVIOR,
@@ -1797,7 +1817,7 @@ static void run_powerloss_exhaustive(
         .powerloss_data     = NULL,
     };
 
-    int err = lfs_emubd_createcfg(&cfg, test_disk_path, &bdcfg);
+    int err = lfs_emubd_create(&cfg, &bdcfg);
     if (err) {
         fprintf(stderr, "error: could not create block device: %d\n", err);
         exit(-1);
@@ -2314,19 +2334,19 @@ invalid_define:
                                     = TEST_LIT(sizes[0]);
                             geometry->defines[PROG_SIZE_i]
                                     = TEST_LIT(sizes[1]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[2]);
                         } else if (count >= 2) {
                             geometry->defines[PROG_SIZE_i]
                                     = TEST_LIT(sizes[0]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[1]);
                         } else {
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[0]);
                         }
                         if (count >= 4) {
-                            geometry->defines[BLOCK_COUNT_i]
+                            geometry->defines[ERASE_COUNT_i]
                                     = TEST_LIT(sizes[3]);
                         }
                         optarg = s;
@@ -2358,19 +2378,19 @@ invalid_define:
                                     = TEST_LIT(sizes[0]);
                             geometry->defines[PROG_SIZE_i]
                                     = TEST_LIT(sizes[1]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[2]);
                         } else if (count >= 2) {
                             geometry->defines[PROG_SIZE_i]
                                     = TEST_LIT(sizes[0]);
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[1]);
                         } else {
-                            geometry->defines[BLOCK_SIZE_i]
+                            geometry->defines[ERASE_SIZE_i]
                                     = TEST_LIT(sizes[0]);
                         }
                         if (count >= 4) {
-                            geometry->defines[BLOCK_COUNT_i]
+                            geometry->defines[ERASE_COUNT_i]
                                     = TEST_LIT(sizes[3]);
                         }
                         optarg = s;
diff --git a/runners/test_runner.h b/runners/test_runner.h
index e30d492..4be72e4 100644
--- a/runners/test_runner.h
+++ b/runners/test_runner.h
@@ -82,19 +82,23 @@ intmax_t test_define(size_t define);
  
 #define READ_SIZE_i          0
 #define PROG_SIZE_i          1
-#define BLOCK_SIZE_i         2
-#define BLOCK_COUNT_i        3
-#define CACHE_SIZE_i         4
-#define LOOKAHEAD_SIZE_i     5
-#define BLOCK_CYCLES_i       6
-#define ERASE_VALUE_i        7
-#define ERASE_CYCLES_i       8
-#define BADBLOCK_BEHAVIOR_i  9
-#define POWERLOSS_BEHAVIOR_i 10
-#define DISK_VERSION_i       11
+#define ERASE_SIZE_i         2
+#define ERASE_COUNT_i        3
+#define BLOCK_SIZE_i         4
+#define BLOCK_COUNT_i        5
+#define CACHE_SIZE_i         6
+#define LOOKAHEAD_SIZE_i     7
+#define BLOCK_CYCLES_i       8
+#define ERASE_VALUE_i        9
+#define ERASE_CYCLES_i       10
+#define BADBLOCK_BEHAVIOR_i  11
+#define POWERLOSS_BEHAVIOR_i 12
+#define DISK_VERSION_i       13
 
 #define READ_SIZE           TEST_DEFINE(READ_SIZE_i)
 #define PROG_SIZE           TEST_DEFINE(PROG_SIZE_i)
+#define ERASE_SIZE          TEST_DEFINE(ERASE_SIZE_i)
+#define ERASE_COUNT         TEST_DEFINE(ERASE_COUNT_i)
 #define BLOCK_SIZE          TEST_DEFINE(BLOCK_SIZE_i)
 #define BLOCK_COUNT         TEST_DEFINE(BLOCK_COUNT_i)
 #define CACHE_SIZE          TEST_DEFINE(CACHE_SIZE_i)
@@ -108,9 +112,11 @@ intmax_t test_define(size_t define);
 
 #define TEST_IMPLICIT_DEFINES \
     TEST_DEF(READ_SIZE,          PROG_SIZE) \
-    TEST_DEF(PROG_SIZE,          BLOCK_SIZE) \
-    TEST_DEF(BLOCK_SIZE,         0) \
-    TEST_DEF(BLOCK_COUNT,        (1024*1024)/BLOCK_SIZE) \
+    TEST_DEF(PROG_SIZE,          ERASE_SIZE) \
+    TEST_DEF(ERASE_SIZE,         0) \
+    TEST_DEF(ERASE_COUNT,        (1024*1024)/ERASE_SIZE) \
+    TEST_DEF(BLOCK_SIZE,         ERASE_SIZE) \
+    TEST_DEF(BLOCK_COUNT,        ERASE_COUNT/lfs_max(BLOCK_SIZE/ERASE_SIZE,1)) \
     TEST_DEF(CACHE_SIZE,         lfs_max(64,lfs_max(READ_SIZE,PROG_SIZE))) \
     TEST_DEF(LOOKAHEAD_SIZE,     16) \
     TEST_DEF(BLOCK_CYCLES,       -1) \
@@ -120,8 +126,8 @@ intmax_t test_define(size_t define);
     TEST_DEF(POWERLOSS_BEHAVIOR, LFS_EMUBD_POWERLOSS_NOOP) \
     TEST_DEF(DISK_VERSION,       0)
 
-#define TEST_IMPLICIT_DEFINE_COUNT 12
 #define TEST_GEOMETRY_DEFINE_COUNT 4
+#define TEST_IMPLICIT_DEFINE_COUNT 14
 
 
 #endif
diff --git a/tests/test_alloc.toml b/tests/test_alloc.toml
index 205efbb..916fc2a 100644
--- a/tests/test_alloc.toml
+++ b/tests/test_alloc.toml
@@ -460,8 +460,8 @@ code = '''
 
 # chained dir exhaustion test
 [cases.test_alloc_chained_dir_exhaustion]
-if = 'BLOCK_SIZE == 512'
-defines.BLOCK_COUNT = 1024
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
     lfs_t lfs;
     lfs_format(&lfs, cfg) => 0;
@@ -538,8 +538,8 @@ code = '''
 
 # split dir test
 [cases.test_alloc_split_dir]
-if = 'BLOCK_SIZE == 512'
-defines.BLOCK_COUNT = 1024
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
     lfs_t lfs;
     lfs_format(&lfs, cfg) => 0;
@@ -587,8 +587,8 @@ code = '''
 
 # outdated lookahead test
 [cases.test_alloc_outdated_lookahead]
-if = 'BLOCK_SIZE == 512'
-defines.BLOCK_COUNT = 1024
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
     lfs_t lfs;
     lfs_format(&lfs, cfg) => 0;
@@ -655,8 +655,8 @@ code = '''
 
 # outdated lookahead and split dir test
 [cases.test_alloc_outdated_lookahead_split_dir]
-if = 'BLOCK_SIZE == 512'
-defines.BLOCK_COUNT = 1024
+if = 'ERASE_SIZE == 512'
+defines.ERASE_COUNT = 1024
 code = '''
     lfs_t lfs;
     lfs_format(&lfs, cfg) => 0;
diff --git a/tests/test_badblocks.toml b/tests/test_badblocks.toml
index b50b393..04ed73f 100644
--- a/tests/test_badblocks.toml
+++ b/tests/test_badblocks.toml
@@ -2,7 +2,7 @@
 if = '(int32_t)BLOCK_CYCLES == -1'
 
 [cases.test_badblocks_single]
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.ERASE_CYCLES = 0xffffffff
 defines.ERASE_VALUE = [0x00, 0xff, -1]
 defines.BADBLOCK_BEHAVIOR = [
@@ -82,7 +82,7 @@ code = '''
 '''
 
 [cases.test_badblocks_region_corruption] # (causes cascading failures)
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.ERASE_CYCLES = 0xffffffff
 defines.ERASE_VALUE = [0x00, 0xff, -1]
 defines.BADBLOCK_BEHAVIOR = [
@@ -161,7 +161,7 @@ code = '''
 '''
 
 [cases.test_badblocks_alternating_corruption] # (causes cascading failures)
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.ERASE_CYCLES = 0xffffffff
 defines.ERASE_VALUE = [0x00, 0xff, -1]
 defines.BADBLOCK_BEHAVIOR = [
diff --git a/tests/test_exhaustion.toml b/tests/test_exhaustion.toml
index 2cf6aed..273dd98 100644
--- a/tests/test_exhaustion.toml
+++ b/tests/test_exhaustion.toml
@@ -1,7 +1,7 @@
 # test running a filesystem to exhaustion
 [cases.test_exhaustion_normal]
 defines.ERASE_CYCLES = 10
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
 defines.BADBLOCK_BEHAVIOR = [
     'LFS_EMUBD_BADBLOCK_PROGERROR',
@@ -94,7 +94,7 @@ exhausted:
 # which also requires expanding superblocks
 [cases.test_exhaustion_superblocks]
 defines.ERASE_CYCLES = 10
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
 defines.BADBLOCK_BEHAVIOR = [
     'LFS_EMUBD_BADBLOCK_PROGERROR',
@@ -188,7 +188,7 @@ exhausted:
 # wear-level test running a filesystem to exhaustion
 [cases.test_exhuastion_wear_leveling]
 defines.ERASE_CYCLES = 20
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
 defines.FILES = 10
 code = '''
@@ -288,7 +288,7 @@ exhausted:
 # wear-level test + expanding superblock
 [cases.test_exhaustion_wear_leveling_superblocks]
 defines.ERASE_CYCLES = 20
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.BLOCK_CYCLES = 'ERASE_CYCLES / 2'
 defines.FILES = 10
 code = '''
@@ -385,7 +385,7 @@ exhausted:
 # test that we wear blocks roughly evenly
 [cases.test_exhaustion_wear_distribution]
 defines.ERASE_CYCLES = 0xffffffff
-defines.BLOCK_COUNT = 256 # small bd so test runs faster
+defines.ERASE_COUNT = 256 # small bd so test runs faster
 defines.BLOCK_CYCLES = [5, 4, 3, 2, 1]
 defines.CYCLES = 100
 defines.FILES = 10