Re: [Qemu-devel] [PATCH v3 2/2] Add Nios II semihosting support.

[Sandra Loosemore <sandra@codesourcery.com>]

On 05/18/2018 03:35 PM, Sandra Loosemore wrote:
> On 05/18/2018 02:19 PM, Julian Brown wrote:
>> On Fri, 18 May 2018 21:52:04 +0200
>> Marek Vasut <marex@denx.de> wrote:
>>
>>> On 05/18/2018 09:23 PM, Julian Brown wrote:
>>>> This patch (by Sandra Loosemore, mildly rebased) adds support for
>>>> semihosting for Nios II bare-metal emulation.
>>>>
>>>> Signed-off-by: Julian Brown <julian@codesourcery.com>
>>>> Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
>>>
>>> Is there some documentation for this stuff ? It looks interesting, but
>>> how can I try it here ?
>>
>> There's no documentation AFAIK apart from that the entry points are
>> the same as m68k, semihosting is invoked with "break 1", and r4/r5 are
>> used for passing arguments. I'm not actually sure how you can try this
>> stuff without our startup code or other infrastructure (that I'm pretty
>> sure we can't divulge). Sandra, any ideas?
> 
> I don't see any reason why we couldn't contribute libgloss support, 
> except that I don't have time to write such a BSP right now.  :-(  I 
> recently did this for C-SKY, though, and the semihosting parts were just 
> a straightforward copy from the m68k port.

I've posted a patch with libgloss semihosting support for nios2 here:

https://sourceware.org/ml/newlib/2018/msg00610.html

I hope this is enough to unblock consideration of the corresponding QEMU 
patch set now.  Here's a link to the original patch posting:

http://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg04571.html

-Sandra