kernel debugger and usb keyboard

Alexander Best alexbestms at math.uni-muenster.de
Thu Jul 16 08:43:29 UTC 2009


if i understood it correctly the reason a usb keyboard cannot be used in the
kernel debugger after a panic is that we can't be sure the panic didn't happen
inside the usb stack so the whole usb stack is discarded at a panic.

maybe this would be a solution:

modern bioses support an option called legcy usb keyboard support. the way i
understood it is that the bios grabs usb keyboard events and uses them to
emulate an AT keyboard. that way e.g. a bootloader can the used  with a usb
keyboard although there's no usb stack or whatever in the bootloader.

when the kernel boots the usb stack takes control over the usb keyboard and
the bios keyboard legacy support gets disabled. couldn't we revert to this
stage after a panic occurs? letting the bios take control over the usb
keyboard again and emulate an AT keyboard?

alex


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