Re: powerpc remote target registers

[Andrew Cagney <cagney@gnu.org>]

> Now, arguably this is a problem with GCC/GAS/GLD: there is a machine type specifically for mpc860 with the correct register definitions, instead of "common" with the correct register definitions. However GCC/GAS don't allow you to set that when compiling objects, and LD appears to ignore my request to set it explicitly when linking (using -A powerpc:mpc860). That shouldn't really be needed anyway, as it should be implied by a compile with -mcpu=860, but GCC doesn't pass anything to GAS/the linker to reflect that. Sigh.
> 
> However I would say that GDB is also mistaken for not initializing the packet buffer in remote_fetch_registers() to 0 first, so that registers that aren't supplied by the remote target don't have uninitialised data, which may include an "x" in them. 

I don't think this fixes the bug.  It will fill each nibble of the 
altivec registers with (0 - '0') instead of zero (you should see this 
with "maint print raw-registers").

Suggest instead changing the for loop filling in regs[] so that it 
doesn't run off the end of the NUL terminated buf[] (I think this is the 
real bug).

Andrew