Re: [PATCH] [gdb] Add Z80 CPU basic support

[Simon Marchi <simark@simark.ca>]

On 2020-09-24 11:21 a.m., Sergey Belyashov wrote:
> чт, 24 сент. 2020 г. в 17:08, Simon Marchi <simark@simark.ca>:
> This code is written by me from scratch. Some code parts are copied from
> other GDB source files.

Thanks.

>> - Did you manage to run parts of the GDB testsuite against this?
>
> GDB testsuit cannot be used, because there are no GCC port to Z80.

GCC is not required, it is possible to write a board file that specifies
another compiler.  It would be good to have a board file that allows a
developer to test a change against Z80.  A bit like
testsuite/boards/simavr.exp for AVR.

>
>> - If I want more information about the Z80 architecture, such as the ISA
>>   details, ABI, etc, where do I look?  It would also be a good idea to
>>   add this to the commit message.
>
> It can be downloaded on Zilog offical site.

Thanks, I see you provided direct links in v3.

>> We want to avoid people dropping code and then leaving a maintenance
>> burden to others.  Ideally, each architecture should have a maintainer
>> (listed in the MAINTAINERS file) responsible for reviewing patches about
>> that architecture, and to whom we can reach out for questions about that
>> architecture.  Would you be ready to accept such a role?
>
> Yes, I'm ready.

Thanks.

>> Shouldn't there be two different target descriptions for Z80 and eZ80?
>
> I have not completely supported the eZ80 in ADL mode, so I do not provide
> a description for it. In legacy Z80 mode eZ80 has the same registers and
> flags as Z80/Z180.

So, do we need to mention eZ80 at all?  Can't we just talk about Z80 and
never talk about eZ80?

>
>>> diff --git a/gdb/stubs/z80-stub.c b/gdb/stubs/z80-stub.c
>>> new file mode 100644
>>> index 0000000000..36316b95ba
>>> --- /dev/null
>>> +++ b/gdb/stubs/z80-stub.c
>>
>> What is this file for?  How do I use it?
>
> This file is used as an embedded debugger monitor. Currently GDB is
> tested with it.

Ok, it would be good to give an example of how to use it, otherwise it's
pretty much dead code (like all other files in this directories are).

Simon