Micropython firmware for ESP-C3-32S

[bboortz]

Hi,

I have a development board with a chip labeled "ESP32-C3-32S". On the backside I have the information "NodeMCU-Series", "ESP-C3-32S-Kit" and "A151". This board: https://www.waveshare.com/wiki/ESP-C3-32S-Kit with a 2mb flash rom.
I have tried several official micropython firmwares but always receive the error "Detected size(2048k) smaller than the size in the binary image header(4096k). Probe failed.". Seems that the prebuild esp32-c3 firmwares I found so far are designed for 4mb flash at least. Can you please tell me which one I have to use?

I did the following:

Erased the flash

$ esptool.py --chip esp32c3 --port /dev/ttyUSB0 erase_flash
esptool.py v4.6.2            
Serial port /dev/ttyUSB0        
Connecting....                                         
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE                                                                                                            
Crystal is 40MHz 
MAC: 7c:df:a1:d3:be:b4
Uploading stub...
Running stub...          
Stub running...                                                                                                                
Erasing flash (this may take a while)...                                                                                       
Chip erase completed successfully in 7.1s
Hard resetting via RTS pin...

flashed the board
I have tried this firmwares

• EPS32-C3: https://micropython.org/resources/firmware/esp32c3-20230426-v1.20.0.bin
• ESP32-C3 with USB: https://micropython.org/resources/firmware/esp32c3-usb-20230426-v1.20.0.bin
• C3 mini: https://micropython.org/resources/firmware/LOLIN_C3_MINI-20230426-v1.20.0.bin

$ esptool.py --chip esp32c3 --port /dev/ttyUSB0 write_flash -z 0x0 firmware/esp32c3-usb-20230426-v1.20.0.bin                   
esptool.py v4.6.2                                                                                                              
Serial port /dev/ttyUSB0                                                                                                                                                                                                                                      
Connecting....                                                                                                                 
Chip is ESP32-C3 (revision v0.3)                                                                                               
Features: WiFi, BLE                                                                                                            
Crystal is 40MHz                                                                                                               
MAC: 7c:df:a1:d3:be:b4                                                                                                         
Uploading stub...                                                                                                              
Running stub...                                                                                                                
Stub running...                                                                                                                
Configuring flash size...                                                                                                      
Flash will be erased from 0x00000000 to 0x00164fff...                                                                          
Compressed 1461232 bytes to 891797...                                                                                          
Wrote 1461232 bytes (891797 compressed) at 0x00000000 in 78.7 seconds (effective 148.4 kbit/s)...                              
Hash of data verified.                                                                                                         
                                                                                                                                                                                                                                                              
Leaving...                                                                                                                     
Hard resetting via RTS pin...

The result is this error:

$ pyserial-miniterm /dev/ttyUSB0 115200
--- Miniterm on /dev/ttyUSB0  115200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
ESP-ROM:esp32c3-api1-20210207
Build:Feb  7 2021
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:1
load:0x3fcd5810,len:0xe3c
load:0x403cc710,len:0x6f4
load:0x403ce710,len:0x28e4
entry 0x403cc710
␛[0;31mE (262) spi_flash: Detected size(2048k) smaller than the size in the binary image header(4096k). Probe failed.␛[0m
Traceback (most recent call last):
  File "_boot.py", line 11, in <module>
  File "inisetup.py", line 34, in setup
  File "inisetup.py", line 7, in check_bootsec
OSError: (-24579, 'ESP_ERR_FLASH_NOT_INITIALISED')
MicroPython v1.20.0 on 2023-04-26; ESP32C3 module with ESP32C3
Type "help()" for more information.
>>> 

flashing other firmwares works
This firmwares are designed for 2mb flash roms and booting without any error:

• AT firmware: https://www.waveshare.com/w/upload/9/92/Esp32-c3-at_firmware_2mb.zip from https://www.waveshare.com/wiki/ESP-C3-32S-Kit
• micropython firmware build by a forum user based on micropython 1.18: https://mega.nz/file/hFcRyQYa#yru2X7h9CxqwCrB_rDGKsZex_3y8dDfKxU-NtCCMWQg found via https://forum.micropython.org/viewtopic.php?f=18&t=11025&sid=d9b90710278770df1b8f2c625cb4ddb3&start=10

[robert-hh]

That's strange. I have boards that look the same, but with 4MB flash. Since the board has an USB/UART bridge and you load to /dev/ttyUSB0, the best match is with the GENERIC_C3 firmware. But that is built for 4MB flash size. So it looks like you have to build your own firmware.

[bboortz]

Hi @robert-hh,
thank you for the fast reply.
I have verifyed the flash size on my board. It is 2mb.

esptool.py --chip esp32c3 --port /dev/ttyUSB0 flash_id
esptool.py v4.6.2
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP32-C3 (revision v0.3)
Features: WiFi, BLE
Crystal is 40MHz
MAC: 7c:df:a1:d3:be:b4
Uploading stub...
Running stub...
Stub running...
Manufacturer: 5e
Device: 6015
Detected flash size: 2MB
Hard resetting via RTS pin...

I will try to build my own firmware. Its my first time. Good example to learn this.
A request to add a build for a esp32-c3 firmware for 2mb flash roms needs to be filed via github issues, right?

[robert-hh]

Issues is primarily dedicated to bugs. Given the huge variety of ESP32 boards, I would the fact that a pre-build firmware is missing for a certain configuration not consider as a bug. I wonder that the ESP32 firmware cannot adjust itself to the actual flash size, like e.g. the ESP8266 firmware does, at least to some extend.

[robert-hh]

I tried to create a GENERIC_C3_2MB image. Attached is the binary and a set of board definition files used to create it.
GENERIC_C3_2MB.zip
micropython.zip

Edit: Before uploading the binary, you may have to erase the flash using esptool.py to wipe out previous install attempts.

[bboortz]

Thank you for your help. I have managed to build a firmware. it works. So the board boots up.
I have used the config from the file sdkconfig.board attached to this thread: https://forum.micropython.org/viewtopic.php?t=11188

my workflow (hope I have copied everthing correctly from my history)
this may help other readers later to build firmware on their own too.

git clone -b v4.4.5 --recursive https://github.com/espressif/esp-idf.git esp-idf-v4.4.5
git clone -b v1.20.0 --recursive https://github.com/micropython/micropython.git/ micropython-v1.2.0
cd esp-idf-v4.4.5
./install.sh
cd ../micropython-v1.2.0
. ../esp-idf-v4.4.5/export.sh # as a zsh user: switch to bash in beforehand
vim py/stackctrl.h # fix https://github.com/orgs/micropython/discussions/12027
make -C mpy-cross
cd ports/esp32/
make submodules
cp -r boards/GENERIC_C3 boards/GENERIC_C3_2MB
vim boards/GENERIC_C3_2MB/sdkconfig.board # copy values from the files from https://forum.micropython.org/viewtopic.php?f=18&t=11025
vim boards/GENERIC_C3_2MB/mpconfigboard.cmake # add line "boards/GENERIC_C3_2MB/sdkconfig.board"
make BOARD=GENERIC_C3_2MB
du -shc build-GENERIC_C3_2MB/firmware.bin
esptool.py --chip esp32c3 --port /dev/ttyUSB0 write_flash -z 0x0 build-GENERIC_C3_2MB/firmware.bin

the file sdkconfig.board I have used

CONFIG_ESPTOOLPY_FLASHMODE_DIO=y
CONFIG_ESPTOOLPY_FLASHFREQ_80M=y
CONFIG_ESPTOOLPY_FLASHSIZE_2MB=y
CONFIG_ESPTOOLPY_FLASHSIZE_4MB=n
CONFIG_PARTITION_TABLE_CUSTOM=y
CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions-2MiB.csv"

the file mpconfigboard.cmake

set(IDF_TARGET esp32c3)

set(SDKCONFIG_DEFAULTS
    boards/sdkconfig.base
    boards/sdkconfig.ble
    boards/GENERIC_C3_2MB/sdkconfig.board
)