[coreboot] ASUS P2-99 with P2B config

[Keith Hui]

Hi Branden,

First, welcome and thanks for helping out with my work!

> I wasn't planning on posting unless I could actually contribute
> something, but since Keith Hui posted last month about his work on
> CBMEM for 440BX and ACPI, I figured I should do some proper testing
> and at least post if it worked out.

There are certainly something you can contribute, which I'll get to in a moment.

> I'm running coreboot on a ASUS P2-99 board with the config copied
> straight from P2B. It's not perfect, but it is stable and I haven't
> found anything that doesn't work that did with the original firmware.
>
> Testing I did over the past week:
>
> 1. Actually made a seperate P2-99 config, I'd been using vanilla P2B
> with no renaming for a few months on it.

I'd like you to pose your config on the list, so I can see how much
different P2-99 is from P2B and if a new mainboard is warranted.

Very long ago, I once got a P2-99 by way of a computer discarded by a
friend of my father. I later traded it for a P3B-F that I still have
today.

I remember it uses a 440ZX northbridge, essentially a low-spec BX (2
slots, 512MB max, 4 PCI slots). What I don't remember is the super I/O
chip it uses.

But from what you wrote, you can run a mostly unmodified P2B build on
it, so no new northbridge support should be necessary.

> 3. Setup a serial console - seems to work fine. I was using I
> different board for flashing anyway, since flashrom doesn't know the
> board enable and the asus flasher only works on with original firmware
> to find the board enable - it can flash coreboot though if you use the
> right flag to tell it to flash the whole rom.

As far as I know in this family of boards only P3B-F needs a board
enable. Try this flashrom command on the board:
# flashrom -p internal
and see if a chip is detected.

You need to get a i386/i686 build of flashrom to the board.

Do you see a chip labelled AS99127F on your board? You may be able to
use the flashrom trick for P3B-F [1] to enable internal flashing.

> 4. Tried Keith Hui's ACPI patches
> (https://review.coreboot.org/c/22067/). It has no problem booting or
> restarting, but linux complains about the acpi. Didn't really expect
> it to work properly on a different board anyway.

Is it complaining about a missing MBRS table? It's an incomplete stub
in the P2B board. I'm going to remove that and just include all the
motherboard resources it declares in the ASL.

> As it stands now, all I've done is run it with a P2B config and not
> verified if everything is working as it should, I barely have beginner
> knowledge of C and nothing on low level x86 or acpi, so I can't
> actually do anything but testing. I can't upload board status for it
> since it's a P2-99 not P2B. I'm also still stuck with with using
> another board and hot swapping chips to flash roms. I should probably
> post on the flashrom list that the board I'm flashing with works as
> well as see if anyone knows anything about the asus board enable (it's
> getting pretty old).

I think the next step is to boot a 100% unmodified P2B build. That
should allow you to run board_status (as far as it is concerned you're
booting a P2B, albeit on a P2-99 hardware), but to actually do it you
need to set yourself up on Gerrit.

>
> The main reason I'm posting is to say I can test patches the patches
> Keith Hui has been working on and post logs. I'd also be glad for any
> other recommendations on what I can do to help with this system.
>

Thanks again!

To recap, our next steps:

Show us your P2-99 Kconfig.
Boot test an unmodified P2B build. Get Gerrit access for yourself so
you can run board_status on it.
Worse come to worst, I'll submit a asus/p2-99 patch for you.
Check if you really need a board enable for flashrom.
I'll submit a patch to move P2B to EARLY_CBMEM_INIT. Boot test it as
soon as you can, since this is required to keep this board in tree
past the real-soon-now 4.7 release.
Then I'll update the ACPI patch for P2B (needs more restructuring
based on feedbacks I received). It should not complain about missing
stuff anymore. We'll go from there.

If you need help pulling in a patch, I'll see how/if I can help.

Keith

[1] https://www.coreboot.org/Board:asus/p3b-f