`espflash read-flash` should also work with `--no-stub`

[SergioGasquez]

Here's the result:

espflash read-flash --no-stub 0x9000 0x6000 ./nvs_dump_devkit   

[2024-10-25T10:45:55Z INFO ] 🚀 A new version of espflash is available: v3.2.0

Error: espflash::stub_required



  × This command requires using the RAM stub

  help: Don't use the `--no-stub` option with the command

Originally posted by @DaneSlattery in #697

esptool allows using read_flash subcommand even without stub: https://github.com/espressif/esptool/blob/6d04155e886ae65bdcb28a7993b43f2476f6ce16/esptool/loader.py#L1274-L1275

❯ esptools tool --chip esp32c6 --no-stub read_flash 0 0x20000 flash_content.bin
Tool esptool mounted as `/home/sergio/.cache/esptools/78c195b08bd57bf27167b323600d417a546d3393/esptool`
Executing `esptool`
esptool.py v4.8.1
Found 33 serial ports
Serial port /dev/ttyUSB0
Connecting....
Chip is ESP32-C6 (QFN40) (revision v0.0)
Features: WiFi 6, BT 5, IEEE802.15.4
Crystal is 40MHz
MAC: 60:55:f9:00:00:f7:1b:6c
BASE MAC: 60:55:f9:f7:1b:6c
MAC_EXT: 00:00
Enabling default SPI flash mode...
Configuring flash size...
WARNING: In case of failure, please set a specific --flash_size.
131072 (100 %)
Read 131072 bytes at 0x00000000 in 22.0 seconds (47.7 kbit/s)...
Hard resetting via RTS pin...
Status Ok(ExitStatus(unix_wait_status(0)))

See https://github.com/espressif/esptool/blob/master/esptool/targets/esp32.py#L393-L418

[SergioGasquez]

According to the docs:

When using the read_flash command in combination with the --no-stub argument, it may be necessary to also set the --flash_size argument to ensure proper reading of the flash contents by the ROM.

https://docs.espressif.com/projects/esptool/en/latest/esp32/esptool/basic-commands.html#read-flash-contents-read-flash

But then, it's listed under "Stub loader only": https://docs.espressif.com/projects/esptool/en/latest/esp32/advanced-topics/serial-protocol.html#supported-by-stub-loader-only