Flashing ESP8266 with a LittleFS binary - esp8266

Question

I'm trying to build a LittleFS file system binary on my PC and flash it to my WeMos D1 Mini Pro (16MB) ESP8266.
I used the following code on the ESP
LittleFS.begin()
FSInfo info;
LittleFS.info(info);
Serial.print("LittleFS block size:");
Serial.println(info.blockSize);
Serial.print("LittleFS total bytes:");
Serial.println(info.totalBytes);
To determine the block size and total bytes, which gave me 8192 and 14655488 respectively. 14655488 / 8192 = 1789 so I used 1789 as the block size in the below python:
from littlefs import LittleFS
fs = LittleFS(block_size=8192, block_count=1789)
with open( 'index.html', 'rb' ) as f:
data = f.read()
with fs.open( '/index.html', 'w') as fh:
fh.write( data )
with open('fs.bin', 'wb') as fh:
fh.write(fs.context.buffer)
This creates a 14655488 bytes .bin file.
I then looked in boards.txt and found these lines:
d1_mini_pro.menu.eesz.16M14M=16MB (FS:14MB OTA:~1019KB)
d1_mini_pro.menu.eesz.16M14M.build.flash_size=16M
d1_mini_pro.menu.eesz.16M14M.build.flash_size_bytes=0x1000000
d1_mini_pro.menu.eesz.16M14M.build.flash_ld=eagle.flash.16m14m.ld
d1_mini_pro.menu.eesz.16M14M.build.spiffs_pagesize=256
d1_mini_pro.menu.eesz.16M14M.upload.maximum_size=1044464
d1_mini_pro.menu.eesz.16M14M.build.rfcal_addr=0xFFC000
d1_mini_pro.menu.eesz.16M14M.build.spiffs_start=0x200000
d1_mini_pro.menu.eesz.16M14M.build.spiffs_end=0xFFA000
d1_mini_pro.menu.eesz.16M14M.build.spiffs_blocksize=8192
This confirms the block size and gives the SPIFFS (but LittleFS is equivalent here, right?) start address as 0x200000
Checking these Arduino bits, i get:
FS_PHYS_ADDR: 2097152 (0x200000)
FS_PHYS_SIZE: 14655488
FS_PHYS_PAGE: 256
FS_PHYS_BLOCK: 8192
So then I used:
python upload.py --chip esp8266 --port COM6 --baud 460800 write_flash 0x200000 fs.bin
which outputs:
esptool.py v2.8
Serial port COM6
Connecting....
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: ec:fa:bc:6e:19:90
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Compressed 14655488 bytes to 215596...
Writing at 0x00234000... (100 %)
Wrote 14655488 bytes (215596 compressed) at 0x00200000 in 56.7 seconds (effective 2067.0 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
However, when I then use code like the below
Dir root = LittleFS.openDir("/");
while (root.next())
{
Serial.print(root.fileName());
}
I get nothing, and
LittleFS.exists("/index.html")
returns false.
What am I doing wrong, or how do I debug this?
I'm uploading my firmware (not the filesystem) via Visual Studio Code, and the board configuration I'm using is
"xtal=80,vt=flash,exception=legacy,ssl=all,eesz=16M14M,ip=lm2f,dbg=Disabled,lvl=None____,wipe=none,baud=921600"
If I open the bin in a hex editor, I can see:
Which is some javascript inside the html file.
If I do this:
uint32_t b;
ESP.flashRead(0x006C2800 + 0x200000, &b, 1);
Serial.println(b);
then it returns 115/0x73, so it looks like the binary has flashed successfully, so that leaves me with either the binary being flashed in the wrong place, or it being corrupted/invalid....

Answer 1

I haven't fixed this exact problem, but I have achieved what I want.
This:
C:\Users\Andrew Bullock\AppData\Local\Arduino15\packages\esp8266\tools\mklittlefs\2.5.0-4-fe5bb56\mklittlefs.exe
exists (instructions here https://github.com/earlephilhower/mklittlefs) which works. So I can only assume that the Python wrapper or the version of LittleFS it's using is somehow incompatible or broken.

Answer 2

The only problem here i can see is that the block_count you gave in your python script is wrong. block_count actually refers to the pageSize of the Filesystem, that holds number of bytes every page is going to hold, in ESP littleFS the pageSize is 256.
So your object initialisation should be like this:
fs = LittleFS(block_size=8192, block_count=259)