[U-Boot] [mips] malta configuration works in qemu-1.5 does not in qemu-1.6

[Paul Burton <paul.burton@imgtec.com>]

On 11/11/13 10:25, Gabor Juhos wrote:
> 2013.11.11. 10:52 keltez?ssel, Daniel Schwierzeck ?rta:
>> 2013/11/10 Alon Bar-Lev <alon.barlev@gmail.com>:
>>> Hello,
>>>
>>> master is: 15c5cdf from Fri Nov 8 15:25:29 2013 -0500
>>> u-boot-2013.10
>>>
>>> Working in qemu-1.5.3.
>>> Does not work in qemu-1.6.1.
>>>
>>> The command prompt is not displayed, 100% cpu consumption.
>>>
>>> ---
>>> $ qemu-system-mips -M malta -nographic -drive if=pflash,file=/tmp/flash -m
>>> 256
>>>
>>>
>>> U-Boot 2013.10-00249-g15c5cdf (Nov 10 2013 - 18:00:48)
>>>
>>> Board: MIPS Malta CoreLV (Qemu)
>>> DRAM:  256 MiB
>>> ---
>>>
>>> Any idea what the difference? any fix pending somewhere?
>>>
>>
>> it is obviously am upstream change in qemu, which requires a fix in u-boot.
>>
>> Paul or Gabor, do you have an idea?
>
> It is broken since the following change in qemu:
>
> commit a427338b222b43197c2776cbc996936df0302f51
> Author: Paul Burton <paul.burton@imgtec.com>
> Date:   Fri Jun 14 08:30:44 2013 +0100
>
>      mips_malta: correct reading MIPS revision at 0x1fc00010
>
>      Rather than modifying the BIOS code at its original location, copy it
>      for the 0x1fc00000 region & modify the copy. This means the original
>      ROM code is correctly readable at 0x1e000010 whilst the MIPS revision
>      is readable at 0x1fc00010.
>
>      Additionally the code previously operated on target memory which would
>      later be overwritten by the BIOS image upon CPU reset if the -bios
>      argument was used to specify the BIOS image. This led to the written
>      MIPS revision being lost. Copying using rom_copy when -bios is used
>      fixes this issue.
>
>      Signed-off-by: Paul Burton <paul.burton@imgtec.com>
>      Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
>      Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
>
> Due to that change, we are getting a CPU exception while probing the
> flash at the 0x1fc00000 address.
>
> Changing the MALTA_FLASH_BASE constant to 0x1e000000 in
> 'arch/mips/include/asm/malta.h' fixes the problem. I will send a patch for that.
>
> -Gabor
>

Aha, thanks for tracking that down. I guess if flash commands need to 
work at 0x1fc00000 then my QEMU patch fixed one bug but causes 
another... I'll try to find the time to fix that in QEMU soon.

Thanks,
     Paul