littleFs without arduino IDE

[natxopedreira]

Hello

I want to try littleFs lib but i'm not a arduino IDE user so i cant use the plugin, seems like the plugin is not only to upload data but also to create the filesystem.... Where i can find info about this?

IMO will be cool to have the option to do this without the ardu plugin, even a python script or a bash....

Thanks!

[natxopedreira]

Ok i think i understand how this works

You first need to create the image that include the "app" + data with mklittlefs
mklittlefs -c dataPath -p spiPage -b spiBlock -s (spiEnd - spiStart) .mklittlefs.bin

And later to upload this you use this python script
uf2conv.py --base (spiStart - 0 * 0x10000000) --serial serialPort --family RP2040 .mklittlefs.bin

Regarding those vars

spiStart = getIntPref("build.fs_start");
spiEnd = getIntPref("build.fs_end");
spiPage = 256;
spiBlock = 4096;

Where i can find, or how to calculate fs_start and fs_end values?
If flash is 4096 bytes and i want to have a 1024 storage size, will those values be????

spiStart = (total memory 4096) - storage_size(1024) = 3072
spiEnd = spiStart +  storage_size(1024) = 4096

[earlephilhower]

Those values need to be encoded in the main app binary. I suggest you build an app w/the appropriate filesystem size set and then open the *.map file generated. There will be a partition table used by the OTA updater you can use to grab the encoded/calculated position and size. For 2MB(1MB FS) :

.partition      0x00000000100026e8      0x918
                0x0000000010002ff0                . = (__flash_binary_start + 0x2ff0)
 *fill*         0x00000000100026e8      0x908
                0x0000000010002ff0        0x4 LONG 0x100ff000
                0x0000000010002ff4        0x4 LONG 0x101ff000
                0x0000000010002ff8        0x4 LONG 0x101ff000
                0x0000000010002ffc        0x4 LONG 0xff000

From linker file:

    .partition : {
        /* Align to the last 16-bytes of the OTA region */
        /* If anyone has a better way of doing this, please submit a PR! */
        . = __flash_binary_start + 0x2ff0;
        LONG(__FS_START__)
        LONG(__FS_END__)
        LONG(__EEPROM_START__)
        LONG(__FLASH_LENGTH__)
    } > FLASH

So look at 0x10002ff0 for FS_START, 0x10002ff4 for FS_END. In this case, FS_START = 0x100ff000 and FS_END = 0x101ff000

[natxopedreira]

Thanks, its working