[coreboot] F2A-85M: Different VGA BIOS needed after CPU Upgrade?

[Daniel Kulesz]

Hi,

to answer this question to myself: It seems like my VGA BIOS was neither working with the A4-5300 APU nor the A10-6700 APU. After debugging the problem over the serial port it turned out that SeaBIOS had multithreading issues and recognized the disks only partially and incorrectly --- which then lead to a boot failure.

To solve this issue, I got the hint on IRC (many thanks!) to apply the following patch (also raises the debug level):


diff --git a/payloads/external/SeaBIOS/Makefile b/payloads/external/SeaBIOS/Makefile
index 4b108d5..10e5aea 100644
--- a/payloads/external/SeaBIOS/Makefile
+++ b/payloads/external/SeaBIOS/Makefile
@@ -37,6 +37,8 @@ checkout: fetch
        cd seabios; git checkout master; git branch -D coreboot 2>/dev/null; git checkout -b coreboot $(TAG-y)
 
 config: checkout
+       echo "CONFIG_DEBUG_LEVEL=5" >> seabios/.config
+       echo "CONFIG_THREADS=n" >> seabios/.config
        echo "    CONFIG     SeaBIOS $(TAG-y)"
        echo "CONFIG_COREBOOT=y" > seabios/.config
 ifeq ($(CONFIG_CONSOLE_SERIAL)$(CONFIG_DRIVERS_UART_8250IO),yy)


After that, my A10-6700 (Richland) worked with Coreboot. I had some stalls on CPU #3 which have gone after applying microcode updates (via the OS). I had the same issue with an older (but not a newer) version of the vendor BIOS, so I assume the CPU really has a bug which prevents reliable multi-core operations. It could be that the SeaBIOS trouble also originate from that, but I haven't tried compiling the microcode in, yet.

Cheers, Daniel



On Tue, 28 Jun 2016 12:23:23 +0200
Daniel Kulesz <daniel.ina1 at googlemail.com> wrote:

> Hi John,
> 
> > It sounds to me as though the PCI id's of the graphics card for the 
> > upgraded CPU may be different (I could be totally wrong about that, so I 
> > defer to others on the list if I'm barking up the wrong tree) and your 
> > coreboot image may need to be updated accordingly. Of course, it could 
> > also be the video BIOS that's the problem as you've suggested.
> 
> Thank you for the hint. I inspected that, but the PCI-IDs actually look the same:
> 
> 00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Trinity [Radeon HD 7480D] [1002:9993]
> (A4-5300)
> 
> and
> 
> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Richland [Radeon HD 8670D] (prog-if 00 [VGA controller])
> (A10-6700)
> 
> Looks like the VGA BIOS is really different:
> 
> # diff vgabios_a4-5300.bin vgabios_a10_6700.bin 
> Binary files vgabios_a4-5300.bin and vgabios_a10_6700.bin differ
> 
> Guess I will have to to "update" the VGA BIOS then.
> 
> Cheers, Daniel
> 
> 
> > 
> > Hi Daniel,
> > 
> > 
> > Kind Regards,
> > 
> > John.
> > 
> > 
> > On 28/06/16 09:24, Daniel Kulesz via coreboot wrote:
> > > Hi folks,
> > >
> > > I upgraded the CPU in my F2A-85M from a A4-5300 (Trinity) to a A10-6700 (Richland). The board had Coreboot installed before with the VGA BIOS extracted from the A4-5300. However, I did not get any video output when trying to boot after the upgrade, so I replaced the flash chip with a backup with the vendor BIOS that works.
> > >
> > > Is it likely that the A10-6700 needs a different VGA BIOS or does this this rather look like a different issue? I don't want to experiment too much because the BIOS chips are hardware-wise pretty fragile (even when using the extractor tool).
> > >
> > > Cheers, Daniel
> > >