On Wed, 06 Feb 2002 13:35:34 +0100, Sebastien Lelarge <[EMAIL PROTECTED]> wrote: >We are trying to use KDB-2.1-ia64 on McKinley processor. It compiles in >the kernel 2.4.17 but when we invoke KDB at the startup with the Pause >key (on an USB keyboard), we get a frozen screen and nothing is >displayed when we strike a key. We think that the problem comes from the >USB. > >The USB driver is included in the kernel (not as module) and the >keyboard works at boot time. It seems that KDB doesn't have the USB >driver in his list of drivers.
arch/*/kdb/kdba_io.c, kdba_read does the keyboard I/O. It currently has support for PC keyboards and serial console. AFAIK USB requires interrupt support which will not work in kdb, kdb deliberately runs with interrupts disabled. A year ago, Greg Kroah-Hartman (USB maintainer) told me that it *might* be possible to write I/O code for USB in polling mode but it does not exist yet. After discussions with one of the USB mainatiners, it might be possible to run a keyboard in boot protocol mode and poll it. Somebody who understands USB needs to write the USB equivalent of get_kbd_char(). It needs to implement part of the host controller code in polling mode then use a modified version of usb_kbd.c. I suggest you use a serial console for now. Apple might have a tech note on how to debug MAC OS-X without a serial port, possibly using USB.
