Hi Riley, Dave, Peter, i386 boot/workaround maintainers,
I ran into a problem getting reboot working with 2.6.11 on an embedded
board. The board has a Geode GX1 with a CS5530A companion. What I observe on
reboot is the "Restarting system" printk, and then a cpu stall/hang. I think
the problem arises because the keyboard controller is disabled by the BIOS,
so the traditional mach_reboot()'s output to port 0x64 is ignored. Then the
386 triple fault issued after mach_reboot() results in a shutdown (because
the hardware doesn't have to detect the triple fault and issue a reset).
That then gives the end result of a stalled cpu/hang.
I found that the CS5530A in question has a "issue system wide reset" bit.
The reboot works cleanly if I write that bit rather than do mach_reboot().
So the following patch is my attempt to incorporate that change into 2.6.11
by adding a X86_REBOOTFIXUPS option. In order to keep reboot.c free of hw
specific fixups, I put it in another file, reboot_fixups.c. I tried to make
it a bit generic so that if there are other reboot related fixups for other
chipsets/boards, there'd be a clean place to put it. Please let me know what
you think.