Re: [Qemu-devel] ARM v4t support

[Filip Navara <filip.navara@gmail.com>]

On Sun, Nov 29, 2009 at 8:00 AM, Rob Landley <rob@landley.net> wrote:
> On Friday 27 November 2009 05:35:26 Filip Navara wrote:
>> On Fri, Nov 27, 2009 at 12:17 PM, Vincent Sanders <vince@kyllikki.org>
> wrote:
>> > I appear to be unable to take a hint, your silence on this patch in
>> > the past probably ought to have been a clue. however this will be the
>> > last time I bother to try and get anything merged so you wont have to
>> > be disturbed again.
>> >
>> > The attached patch adds V4t support to the ARM emulation, its pretty
>> > much the same as the last time it was posted. It is correct in
>> > everything it does to the best of my knowledge however you will as
>> > usual no doubt find a corner case it does not cover and reject it.
>>
>> I have already sent more complete patch for ARM7TDMI emulation:
>>
>> http://www.mail-archive.com/qemu-devel@nongnu.org/msg17205.html
>> http://patchwork.ozlabs.org/patch/36841/
>
> That's a link to an archive that gives you html but not a raw patch.  (Huh, it
> says you sent it to the list but I'm not finding it in my mail folder.
> Rummage, rummage, rummage...  Ah, your original patch was dated December 31
> 1969.)

Yep, a bug in TortoiseGIT that was later fixed.

> Ok, dug it up, applied it, booted an -M versatilepb kernel built with an
> armv4tl compiler that I'm assured works for real armv4tl hardware, and I get
> no boot messages if I say "-cpu arm7tdmi", but it boots fine if I don't say
> that.
>
> Let's try my armv4l setup (which I've booted on real armv4tl hardware, albeit
> with a different kernel .config but qemu hasn't got a board emulation for the
> Tin Can Tools Hammer, last I checked...)  That's an OABI which doesn't depend
> on the Thumb extensions...
>
> Nope, that's armv4 OABI, and I've tested the output of that compiler on real
> hardware, albeit with a different kernel .config.
>
> Your patch does not work for me.  Is there a kernel .config change I need to do
> for this?  Looking in the kernel kconfig stuff, the only way to select arm7tdmi
> is to disable MMU support.  Is this a nommu processor?  (I know there are
> armv4t processors _with_ mmu...)

It is nommu processor, so I would be surprised to see any of the
kernels running. Unfortunately I don't have a ready-to-use kernel
.config file for it, since I never even tried it with Linux.

> What kernel .config, -M, and -cpu and  did you use to test an armv4t system
> image with your patch?

-M at91pes (which is included in other patches from around the same
time, but was never merged)
-cpu arm7tdmi
the images I used for the test were mostly Atmel examples, FreeRTOS
and other non-Linux systems.

Best regards,
Filip Navara