Re: [coreboot] seabios failure with v2 and -fomit-frame-pointer

[Kevin O'Connor]

On Wed, Mar 18, 2009 at 02:17:57PM -0600, Myles Watson wrote:
> I think the breakage is occurring before the payload executes, but I'm
> not sure of that.
>
> qemu: fatal: Trying to execute code outside RAM or ROM at 0xf10002ba

The bug is in src/arch/i386/boot/boot.c.  The inline assembly in
jmp_to_elf_entry uses the "g" flag to pass in parameters.  However,
"g" allows gcc to use stack relative addressing of parameters.
Unfortunately, the inline assembly modifies %esp - and thus the stack
relative values become incorrect.

As a guess, without -fomit-frame-pointer, gcc would pass use %ebp
relative values and this wouldn't trigger - but regardless it is still
a bug.

-Kevin