Re: [Qemu-devel] [PATCH v3 2/2] ppc: Add aCube Sam460ex board

[BALATON Zoltan <balaton@eik.bme.hu>]

On Tue, 20 Feb 2018, Alexander Graf wrote:
> On 02/20/2018 11:09 AM, BALATON Zoltan wrote:
>> On Tue, 20 Feb 2018, David Gibson wrote:
>>> On Mon, Feb 19, 2018 at 11:34:25AM +0100, BALATON Zoltan wrote:
>>> 1;5002;0c> Add emulation of aCube Sam460ex board based on AMCC 460EX 
>>> embedded SoC.
>>>> This is not a complete implementation yet with a lot of components
>>>> still missing but enough for the U-Boot firmware to start and to boot
>>>> a Linux kernel or AROS.
>>>> 
>>>> Signed-off-by: François Revol <revol@free.fr>
>>>> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
>>> 
>>> I'm not thrilled with having a machine type that can't be used without
>>> extracting a bootloader image from somewhere, but from the other
>>> thread that's not easy to fix.
>> 
>> This is not meant to be like that and I'd like to also submit the u-boot 
>> image once we figure out how to do it. Especially because the boot loader 
>> one can extract from the updater is buggy but here's a fixed binary that 
>> works here: http://zero.eik.bme.hu/~balaton/qemu/
>> 
>> U-Boot is GPL so we would need to include the source as well (the README in 
>> the link above contain the source URL and the patches needed are there as 
>> well). If there's no easy way to host it in the QEMU repo I could put it in 
>> my own git repo and submit a patch to use that as a submodule if that's 
>> acceptable. It seems there are some firmware images that reference external 
>> git repos already but not sure what's the preferred way.
>
> IMHO the preferred way would be to integrate sam460ex support in upstream 
> U-Boot and just build it from there. We already mirror U-Boot on git.qemu.org 
> and package up that tree, so packaging up one more target from there would be 
> trivial.

As discussed in other thread that's not really feasible. Upstream U-Boot 
has removed support for this CPU and the board code was never upstreamed 
by the hardware vendor. I'm not willing to take the task of porting this 
to latest U-Boot, re-adding all necessary CPU support to latest U-Boot and 
then take on supporting all this in future versions. So it has to be a 
separate source or you'd have to downgrade U-Boot on git.qemu.org to the 
older version where the patch applies (but that's not desired as this old 
version has some bugs which are fixed in later U-Boot versions). We also 
cannot omit the vendor patches to U-Boot and use latest upstream U-Boot 
for this board because guests rely on these firmware modifications to 
boot. So I see no way to have one U-Boot version to be used by both e500 
and sam460ex even if it means adding another U-Boot source (but this 
source is fairly static, I don't expect many changes to it so it won't 
diverge more than it is now and we mainly need to add it to satisfy GPL so 
we can bundle the binary).

Regards,
BALATON Zoltan