From c7f81c9453375d6416658995eafd3397cb9bba1d Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 2 May 2007 19:27:20 +0200 Subject: [PATCH] i386: Verify important CPUID bits in real mode Check some CPUID bits that are needed for compiler generated early in boot. When the system is still in real mode before changing the VESA BIOS mode it is possible to still display an visible error message on the screen. Similar to x86-64. Includes cleanups from Eric Biederman Signed-off-by: Andi Kleen --- arch/i386/boot/setup.S | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'arch/i386/boot') diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S index b74b7f40b79c..f8b3b9cda2b1 100644 --- a/arch/i386/boot/setup.S +++ b/arch/i386/boot/setup.S @@ -302,7 +302,24 @@ good_sig: loader_panic_mess: .string "Wrong loader, giving up..." +# check minimum cpuid +# we do this here because it is the last place we can actually +# show a user visible error message. Later the video modus +# might be already messed up. loader_ok: + call verify_cpu + testl %eax,%eax + jz cpu_ok + lea cpu_panic_mess,%si + call prtstr +1: jmp 1b + +cpu_panic_mess: + .asciz "PANIC: CPU too old for this kernel." + +#include "../kernel/verify_cpu.S" + +cpu_ok: # Get memory size (extended mem, kB) xorl %eax, %eax -- cgit v1.2.3