Re: compatibility between gdb and stub

[Steven Johnson <sjohnson@neurizon.net>]

The real problem here is that the Common Registers of PowerPC are not 
uniform across the chips. I think the only ones that can truly be said 
to be common are R0-R31,pc,msr,lr,ctr,flags  The macros defined, assume 
a whole lot about what is common, that isn't.

And having written an "old stub" for the MPC860, I can confidently say 
that old stubs did not supply zeros where fpscr is, they didn't send 
anything as GDB did not expect anything.

Obviously there would need to be some understanding in the stub of what 
registers GDB used, but I fail to see that GDB is ever going to 
permenantly define a packet layout and stick to it.

Steven

> 
> No.  An old stub would supply zeros instead of "fpscr".
> 
>> This is clumsy, but the 'qRegisters' packet should improve this 
>> behaviour :-)
> 
> 
> qRegisters isn't a `silver bullet' :-/  The bottom line is that GDB and 
> the stub need to agree to a packet layout and then stick to it.
> 
> Andrew
> 
> 
>