[U-Boot] [RFC 3/3] MIPS: bootm.c: integrate QEMU specific functions

Daniel Schwierzeck
2013-01-10T14:22:36Z

2013/1/10 Gabor Juhos <juhosg@openwrt.org>:
> 2013.01.08. 20:14 keltez?ssel, Gabor Juhos ?rta:
>> The linux starting code of the qemu specific bootm
>> implementation is very similar to the one which is
>> used for regular boards. The preparation code is
>> different but it makes no sense to keep that in a
>> separate file.
>>
>> The pach moves the qemu specific code into bootm.c,
>> and removes the custom file. This allows to get rid
>> of some duplicated code, and it collects bootm specific
>> code into a single file. Additionaly, this allows to use
>> the prep,go subcommands in qemu as well.
>>
>> Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
>> Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
>> ---
>> This is compile tested only. I don't have suitable kernel
>> images for mips,mipsel,mips64,mipsel64 systems to try it yet.
>
> Ok, I have tried this with the sample vmlinux image provided here:
> ftp://ftp.denx.de/pub/contrib/Jean-Christophe_Plagniol-Villard/qemu_mips/
>
> It works as expected:
>
>
> Additionally, I wanted to compile a Linux kernel for mips64/mipsel/mipsel64 to
> test these patches on those as well. However when I have tried to configure a
> recent kernel I noticed that it has no MIPS QEMU platform. That has been
> completely removed from Linux five years ago by:
>
> commit 302922e5f6901eb6f29c58539631f71b3d9746b8
> Author: Ralf Baechle <ralf@linux-mips.org>
> Date: Tue Jan 29 10:15:02 2008 +0000
>
> [MIPS] Qemu: Remove platform.
>
> The Qemu platform was originally implemented to have an easily supportable
> platform until Qemu reaches a state where it emulates a real world system.
> Since the latest release Qemu is capable of emulating the MIPSsim and
> Malta platforms, so this goal has been reached. The Qemu plaform is also
> rather underfeatured so less useful than a Malta emulation.
>

yes, I figured that too yesterday while testing.

> Maybe the qemu_mips specific bootm stuff should be removed completely from U-Boot?
>
> -Gabor

I agree. Maybe we should convert the current MIPS Qemu port to MTI
Malta. I have seen
that BareBox already supports Qemu Malta.
For supporting real MTI Malta hardware there is AFAIK some work in progress [1].

[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/140428/focus=140541

--
Best regards,
Daniel