[coreboot] PC Engines apu2 boot regression

[Kyösti Mälkki]

On Fri, May 4, 2018 at 6:37 PM, Aaron Durbin <adurbin at google.com> wrote:
> On Fri, May 4, 2018 at 9:23 AM, Piotr Król <piotr.krol at 3mdeb.com> wrote:
>> Hi Aaron,
>> I tried to boot PC Engines apu2 on recent master branch and discovered
>> that it not boot. Bisection points to:
>>
>> 60320182d011 console: only allow console messages after initialization
>>
>> It is hard to believe that this change cause AGESA reset loop, but I
>> checked 3 times. After applying above commit I end up with loop:
>>
>> coreboot-4.7-441-g60320182d0 Fri Mar  2 15:22:24 UTC 2018 romstage
>> starting...
>> BSP Family_Model: 00730f01
>> cpu_init_detectedx = 00000000
>> agesawrapper_amdinitreset() entry
>> CBFS: 'Master Header Locator' located CBFS at [200:7fffc0)
>> CBFS: Locating 'AGESA'
>> CBFS: Found @ offset 5ffdc0 size 7b0e0
>> CBFS: 'Master Header Locator' located CBFS at [200:7fffc0)
>> CBFS: Locating 'AGESA'
>> CBFS: Found @ offset 5ffdc0 size 7b0e0
>> Fch OEM config in INIT RESET Done
>>
>> Any idea what can be result of such weird behavior?
>
> I think it's because we still have boards that utilize CAR_GLOBAL, but
> don't handle migration of CAR globals. Those two things combined
> really makes for situations that just don't work and ramstage loading
> is just lucky to work on those platforms. I was originally thinking
> this patch would work, but I don't think that's the case because when
> I build apu2 CONFIG_EARLY_CBMEM_INIT is already set. If you revert
> that patch what does your log look like? We could be recursively
> entering into car_get_var_ptr() through the printk() path, but that
> would require things not marked as CAR_GLOBAL being passed to that
> function. There is one way to fix all of these scenarios: remove CAR
> migration by transitioning everyone to postcar stub between romstage
> and ramstage. That's a lot of work, though. We can try and debug
> further because I'm not clear why things aren't working.
>

Well I am looking at this as well now.

I have not booted vanilla master on apu2 for sometime, being preparing
POSTCAR_STAGE for these binaryPI boards instead..

Kyösti