Hello devs,
I'm playing around with some LittleFS configuration on an STM32G0 device. I
have the following snippet:
```
#ifdef CONFIG_MTD_PROGMEM
struct mtd_dev_s * mtd;
/* Initialize on-chip program memory support */
mtd = stm32_progmem_initialize();
if (mtd == NULL)
{
syslog(LOG_ERR, "ERROR: stm32_progmem_initialize() failed\n");
}
else
{
ret = ftl_initialize(0, mtd);
if (ret < 0)
{
syslog(LOG_ERR, "ERROR: ftl_initialize() failed: %d\n", ret);
}
}
#endif /* CONFIG_MTD_PROGMEM */
#ifdef CONFIG_FS_LITTLEFS
ret = nx_mount("/dev/mtdblock0", "/mnt/progmem", "littlefs", 0,
"autoformat");
if (ret < 0)
{
syslog(LOG_ERR, "ERROR: Failed to mount littlefs at /mnt/progmem:
%d\n", ret);
}
#endif
```
(I'm omitting the internals, but I've implemented the "progmem" layer for
the STM32G0 with the required "up_" functions).
So far the code runs correctly until the "nx_mount" call is reached. It
fails with "ret = -28", which stands for "ENOSPC". I've been digging around
some forums and it seems the LFS configuration may be wrong. For instance:
```
fs->cfg.context = fs;
fs->cfg.read = littlefs_read_block;
fs->cfg.prog = littlefs_write_block;
fs->cfg.erase = littlefs_erase_block;
fs->cfg.sync = littlefs_sync_block;
fs->cfg.read_size = fs->geo.blocksize *
CONFIG_FS_LITTLEFS_READ_SIZE_FACTOR;
fs->cfg.prog_size = fs->geo.blocksize *
CONFIG_FS_LITTLEFS_PROGRAM_SIZE_FACTOR;
fs->cfg.block_size = fs->geo.erasesize *
CONFIG_FS_LITTLEFS_BLOCK_SIZE_FACTOR;
fs->cfg.block_count = fs->geo.neraseblocks /
CONFIG_FS_LITTLEFS_BLOCK_SIZE_FACTOR;
fs->cfg.block_cycles = CONFIG_FS_LITTLEFS_BLOCK_CYCLE;
fs->cfg.cache_size = fs->geo.blocksize *
CONFIG_FS_LITTLEFS_CACHE_SIZE_FACTOR;
```
The geometry is directly obtained from the underlying FTL MTD device. For
this particular case, I'm reserving 4KB at the end of the flash to be used
as user memory with a fixed page size of 2KB and 2 pages.
- up_progmem_neraseblocks -> 2
- up_progmem_isuniform -> true
- up_progmem_pagesize(n) -> 2048
- up_progmem_erasesize(n) -> 2048
I've tried changing the different LFS configurations, so now I have:
- CONFIG_FS_LITTLEFS_READ_SIZE_FACTOR=1
- CONFIG_FS_LITTLEFS_PROGRAM_SIZE_FACTOR=1
- CONFIG_FS_LITTLEFS_BLOCK_SIZE_FACTOR=1
- CONFIG_FS_LITTLEFS_BLOCK_CYCLE=200 (default)
- CONFIG_FS_LITTLEFS_CACHE_SIZE_FACTOR=1
- CONFIG_FS_LITTLEFS_LOOKAHEAD_SIZE=0
- CONFIG_FS_LITTLEFS_ATTR_MAX=1022 (default)
Is there anything I need to tweak or adjust for LFS to work? So far I've
been unable to make it, it fails on the mount stage.
Thanks in advance,
Javier Alonso (he, him, his)
Geotab
Team Lead - Embedded Systems | GEUR
