Re: [PATCH 0/3] gdbstub: add support for switchable endianness

[Peter Maydell]

On Tue, 24 Aug 2021 at 00:05, Changbin Du <changbin.du@gmail.com> wrote:
>
> On Mon, Aug 23, 2021 at 04:30:05PM +0100, Peter Maydell wrote:
> > changes to be more capable of handling dynamic target changes
> > (this would also help with eg debugging across 32<->64 bit switches);
> > as I understand it that gdb work would be pretty significant,
> > and at least for aarch64 pretty much nobody cares about
> > big-endian, so nobody's got round to doing it yet.
> >
> Mostly we do not care dynamic target changes because nearly all OS will setup
> endianness mode by its first instruction. And dynamic changes for gdb is hard
> since the byte order of debugging info in elf is fixed. And currently the GDB
> remote protocol does not support querying endianness info from remote.
>
> So usually we needn't change byte order during a debug session, but we just 
> want
> the qemu gdbstub can send data in and handle data it received in right byte 
> order.
> This patch does this work with the help of users via the option 'endianness='.

I'm not a huge fan of putting in workarounds that deal with the
problem for specific cases and require users to tweak options settings,
rather than solving the problem in a more general way that would
let it all Just Work for all cases.

-- PMM