On Tue, Aug 24, 2021 at 10:11:14AM +0100, Peter Maydell wrote: > On Tue, 24 Aug 2021 at 00:05, Changbin Du <changbin...@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. > Probably we can add a new callback 'gdb_get_endianness' for CPUClass, and use this callback to determine if bswap is needed every time we read/write cpu registers. What's your thought?
> -- PMM -- Cheers, Changbin Du
