> 
> The above file needs to be common between the arm platforms
> so that gdb support for kcore and kernel debugging can work.
> It would be nice if all registers could be contained in the
> pcb as that greatly simplifies gdb support.

Can we also ensure that there is enough space in this structure to save 
the VFP context. This will require (at a minimum) space for 2 32-bit 
control registers and 32 32-bit float registers (which can be used in 
pairs to give 16 64-bit registers).  Due to the way the VFP can dump its 
registers with FSTMX we will also need 2 32-bit words of additional 
storage in the fp-register bank.  By my calculations that comes to 36 
Words of storage.

The VFP also has one additional 32-bit register which is read-only.  The 
contents of this register will probably be needed by debuggers if they are 
to analyse the crash dump.  I guess it should also be stored in the pcb, 
though its value will never change.

Assuming a process can either be enabled for VFP code or FPA code, but not 
both, I guess we could overlay the information on the FPE status, and use 
a control byte to tell us which is in use.  [Do we want to make such an 
assumption?]

R.