[U-Boot] u-boot x86 on qemu

[Simon Glass]

Hi Jose,


On 28 January 2014 12:17, José Marinho <zemanel at gmail.com> wrote:
> Hi all,
> I am using u-boot from git://git.denx.de/u-boot-x86.git
> I build u-boot by:
>         make coreboot-x86_config
>         make
>
> u-boot is then set as a payload for coreboot.
>
> I then run coreboot as a bios for qemu:
>         qemu-system-i386 -bios ./build/coreboot.rom -m 1g -nographic -s -S
>
> the system hangs when calling the function
>         u64 get_ticks()
>
> because gd->arch.tsc_base is false and hence
> panic("No tick base available"); is executed.
>
> panic will itself call udelay(100000 )
> which in turn calls __udelay (kv)
> which finally calls get_ticks() again.
>
> There is then a recursive behavior here which will go on executing until
> the stack is "depleted".
>
> Has anyone come across this behavior?
> what could be the reason for the tick base not to be set properly?

I believe you might need to build Coreboot in a certain way (with the
timestamp feature enabled perhaps?) But the code is supposed to deal
with that, so this is a bug.

/* We assume that 0 means the base hasn't been set yet */
if (!gd->arch.tsc_base)
panic("No tick base available");

My suggestion would be to either remove this code, or add a warning
instead. From memory there was some suggestion in a code review that
we produce an error when Coreboot does the wrong thing, but I don't
personally think this is that important.

Regards,
Simon