On 1/19/25 7:50 PM, Dragan Simic wrote:
Selecting the CONFIG_SYS_CONSOLE_ENV_OVERWRITE option actually prevents the CONFIG_USB_KEYBOARD option from working as expected, i.e. USB keyboards end up not working as console inputs when "usbkbd" is properly specified as part of the value of the "stdin" environment variable. Describe this clearly in the two relevant Kconfig files, to prevent any possible confusion.
In more detail, the console_init_r() function ends up overwriting the "stdin" environment variable so it contains only the devices available at that point (which doesn't include "usbkbd"), while the "usb start" operation is performed much later, at which point the probe_usb_keyboard() function cannot assign any discovered USB keyboards to the console because "usbkbd" is no longer present in the "stdin" environment variable.
Wouldn't it be better to patch console_init_r() , check if "stdin" variable contains 'usbkbd' and if so, start USB and register the keyboard as stdin device at this point ? This is called after relocation, so starting USB should be OK to do here. The behavior should then be less confusing to users too.