yesterday I tried to reactivate my old 486 box and wanted to install a
current Linux with latest kernel on it. But it turned out that the
latest kernel does not boot because the machine crashes early in the
setup code.
After some debugging it turned out that the problem is the query_ist()
function. If this interrupt with that function is called the machine
simply locks up. It looks like a BIOS bug. Looking for a workaround for
this problem I wrote the attached patch. It checks for the CPUID
instruction and if it is not implemented it does not call the speedstep
BIOS function. As far as I know speedstep should be available since some
Pentium earliest.
Alan Cox observed that it's available since the Pentium II, so cpuid
levels 4 and 5 can be excluded altogether.
H. Peter Anvin cleaned up the code some more:
> Right in concept, but I dislike the implementation (duplication of the
> CPU detect code we already have). Could you try this patch and see if
> it works for you?
which, with a small modification to fix a build error with it the
resulting kernel boots on my machine.
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch lets the early real mode code look for the 'quiet' option
on the kernel command line and pass a loadflag to the decompressor.
When this flag is set, we suppress the "Decompressing Linux... Parsing
ELF... done." messages.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Remove old comments that include the old arch/i386 directory.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we use the bootloader-provided stack pointer, we might end up in a
situation where the bootloader (incorrectly) pointed the stack in the
middle of our heap. Catch this by simply comparing the computed heap
end value to the stack pointer minus the defined stack size.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Push video mode setup as late as possible; messages issued through the
BIOS interface after video mode setup will either not be seen (for
framebuffer modes) or will screw up the cursor (for text modes.)
In particular, this makes the EDD probing message show up correctly.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Make <asm/setup.h> usable by the boot code.
Clean up vestiges of the old command-line protocol from setup.h and
head_32.S (it is still supported from the boot loader point of
view, since it is converted to the new command-line protocol by the
boot code.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Joerg Roedel