Re: RISC-V: Is it reasonable to extend current target_description for KGDB?

On Tue, 15 Oct 2019, Jim Wilson wrote:

> One possible solution is to add a RISC-V specific command to choose
> the register set used for the default p packet.  That way, if there
> are problems with adding registers to it, people have the option to
> switch back to the old way.  We already have the "set riscv
> use-compressed-breakpoints [auto|on|off]" command.  So we could add a
> similar command to choose the number of registers in the default p
> packet, try changing the default to the full 36 register set, and wait
> to see who complains.  People that complain can be told about the
> command to switch back to the old 32 (33?) register set.

 There's such a generic command already available:

(gdb) set tdesc filename ...

 NB, this has nothing to do with the use of `g'/`G' vs `p'/`P' packets, 
both use the same register indices; for the overlapping part, that is of 
course.  Then no heuristics can cover registers outside the range of the 
`g'/`G' packets of course, an XML description does have to be provided for 
those registers to be recognised.

  Maciej