Interrupt U-boot uploading images via USB-DFU

[mishuk]

Hello,

I use STM32MP1 SoC. According to wiki I can interrupt uploading images with STM32 Cube Programmer via USB-DFU: For USB boot, you can easily interrupt this command stm32prog usb 0by pressing Ctr + C in the console without U-Boot modification. 

U-boot also prints in its console "Ctrl+C to exit", but in fact I cannot send "Ctrl+C".  It looks like U-boot console is read-only while uploading via USB-DFU.  What is wrong ?

At normal boot (from eMMC), I can interrupt U-boot loading and use console perfectly.  I use minicom for U-boot console

[PatrickD]

Hi,

the U-Boot console is deactivated only for serial boot over UART.

But for serial boot over USB, the U-Boot console is functional (read and write), and the reception of the Ctrl^C in the console is handled in the DFU loop to interrupt the pending request.

see => source/common/dfu..::run_usb_dnl_gadget()

		if (ctrlc())
			goto exit;

Your issue is perhaps linked to management of special character for the used tools for console: minicom.

For normal boot, the boot command is interruption by any key pressed, Ctrl^C is not required. But it is required to interrupt the DFU command.

On my side I use picocom on Linux on avoid some strange side effect of minicom (as this tools was designed for communication with modem).

Can you try with a more simple terminal tool?

Patrick

[mishuk]

I tried using picocom without success.

While normal boot I can write into U-boot console.  For instance, if I boot from eMMC and press Ctrl+C I get this string in U-boot:

STM32MP> <INTERRUPT>

While uploading images via USB-DFU with STM Cube Programmer I get the prompt

UPLOAD ... done
Ctrl+C to exit ...

But Ctrl+C still does not work, U-boot console seems read-only.

Moreover, when I try to boot from SD card without SD card, I get U-boot prompt

Card did not respond to voltage select!
mmc_init: -95, time 12
STM32MP>

but I cannot enter commands neither