Re: [Qemu-devel] [PULL 0/2] M68k for 2.12 patches

[Laurent Vivier]

Le 02/04/2018 à 20:13, Rob Landley a écrit :
> On 03/30/2018 12:00 PM, Laurent Vivier wrote:
>> Le 30/03/2018 à 18:54, Rob Landley a écrit :
>>> On 03/20/2018 04:08 AM, Laurent Vivier wrote:> This series of patches is 
>>> needed
>>> to fix a problem
>>>> in the m68k translator that can crash QEMU when translation
>>>> cache has too many instructions:
>>>>
>>>>   qemu-m68k: tcg/tcg.c:883: tcg_temp_alloc: Assertion `n < 512' failed.
>>>>   qemu: uncaught target signal 11 (Segmentation fault) - core dumped
>>>>
>>>> I have reproduced it in linux user mode, with "ghc", and in
>>>> system mode with the debian-installer for unstable distro
>>>> from debian-ports.
>>>
>>> If someone wanted to follow along with your "boot linux on qemu-system-m68k"
>>> work on https://github.com/vivier/qemu-m68k, which of the 51 branches should
>>> qemu-system-m68k with like -M q800 or whatever you had working be built 
>>> from?
>>
>> The branch to use is q800-dev
> 
> There isn't any m68k support in musl-libc yet, so I grabbed my old
> https://github.com/landley/aboriginal project, did a "./build.sh m68k", built
> your q800-dev branch, added the m68k-softmmu from that to the start of the
> $PATH, and ran "more/dev-environment-from-build.sh m68k".
> 
> It booted Linux to a shell prompt, I could wget a file from the internet, and
> /home had the 2 gigabyte ext3 mount from the virtual block device.
> 
> I.E. it works for me. Why is it still out of tree?

Remaining patches need some cleanup before being submitted.

I have to submit some enhancements in the FPU emulation, but as they
modify fpu/softfloat.c, I don't want to put them as is in an m68k pull-req:

        target/m68k: manage FPU exceptions
        softfloat: define floatx80_is_any_nan for m68k
        softfloat: disable floatx80_invalid_encoding() for m68k

I have to add some specific m68k hardware emulation:

        m68k: add via support
        m68k: add video card
        q800: Apple Sound Chip (ASC) emulation
        q800: add Nubus support
        q800: add a dummy SWIM floppy controller
        m68k: define Macintosh Quadra 800

but via support should be rewritten as Mark has introduced a new generic
mos6522 VIA device.

I have to update some existing hardware emulation:

        ESP: add pseudo-DMA as used by Macintosh
        escc: introduce a selector for the register bit
        dp8393x: fix receiving buffer exhaustion
        dp8393x: put DMA temp buffer in the state, not in the stack
        dp8393x: manage big endian bus
        dp8393x: fix dp8393x_receive

So, this only needs some work and time. I hope q800 will be available in
QEMU 2.13.

Thanks,
Laurent