Re: [Qemu-devel] [Qemu-ppc] [PATCH 0/9] PPC: e500: Use u-boot as firmware

[Alexander Graf <agraf@suse.de>]

On 15.05.14 18:32, Alexander Graf wrote:
> Today we don't run any firmware on our e500 platform. You're either running
> a Linux kernel directly through -kernel or you don't boot the VM at all.
>
> This is bad for multiple reasons. The normal firmware on e500 based systems
> is u-boot. Some OSes (IIRC FreeBSD) rely on u-boot for their 2nd stage boot
> loader. Since that relies on interfaces u-boot provides we can't execute it
> today.
>
> The other case where we're falling short of expectations that I'm aware of
> is network boot. With a firmware you can actually pxe boot a virtual machine.
>
> This patch set implements all the pieces necessary to run u-boot as the
> firmware for our e500 platforms: mpc8544ds and e500plat. It is based on upstream
> u-boot code that implements a target specific for the simplified system QEMU
> implements.
>
> Due to popular demand the default -kernel booting has *not* been changed from
> directly booting into the kernel. This is possible because we don't need to run
> firmware to provide run time services.
>
> However, whenever the user explicitly defines a -bios blob, we run it.
> That means if you want to route a -kernel boot through u-boot you have to pass
> in -bios pc-bios/u-boot.e500 -kernel uImage.
>
> Please try out as many things as you're able to try.
>
> Known missing bits:
>
>    - -boot doesn't get interpreted yet
>    - pflash is missing, so the environment is volatile
>    - no block drivers available (ata_piix is broken in u-boot and virtio-blk
>      is missing)
>    - KVM patches to support u-boot are probably going to hit 3.16

This is v2 of the patch set.

v1 -> v2:

   - correct permission access to USER_RO
   - Update to newer u-boot version
   - Add git submodule for u-boot
   - skip u-boot when -kernel and no -bios are given


Alex