Re: [Qemu-devel] [PATCH] fw_cfg: fix endianness in fw_cfg_data_mem_read() / _write()

[Laszlo Ersek]

On 12/31/14 18:44, Peter Maydell wrote:
> On 31 December 2014 at 17:17, Peter Maydell <address@hidden> wrote:
>> Unpatched QEMU + QEMU_EFI.fd.v4 : doesn't boot (doesn't load kernel)
>> Patched QEMU + QEMU_EFI.fd.v4_noswizzle : boots OK (dracut-initqueue
>> starts downloading things).
> 
> Just noticed you asked for the full matrix of tests:
> patched QEMU + fd.v4 : doesn't boot (doesn't load kernel)
> unpatched + noswizzle : boots OK
> 
> That's a bit confusing...

It's not confusing. When you run unpatched qemu *on a big endian host*,
that's identical to what the patched code does *on a big endian host*.

The full matrix actually has 8 elements (3 dimensions with 2 values per
dimension) -- host endianness, patched qemu vs. unpatched qemu, and
swizzling vs. non-swizzling firmware.

Thanks,
Laszlo