Re: [RFC] Register sets

[Daniel Jacobowitz <drow at mvista dot com>]

On Thu, Sep 04, 2003 at 06:59:06PM -0400, Andrew Cagney wrote:
> 
> >   I'd really rather not enforce that - remote can provide regsets that
> >   BFD doesn't know about, and the ".reg" names would look silly being
> >   defined as part of the remote protocol.  My instinct says that the
> >   flexibility is worthwhile so that the two implementation details don't
> >   become coupled.
> >
> >I'm with Daniel here.  For most OS'es the corefile format isn't under
> >our control, and some of these formats simply don't make too much
> >sense.  We shouldn't be forced to use those in the remote protocol.
> >And I don't think BFD should do a transformation on the corefile data
> >when it turns the register data into a section.
> 
> ... but here there is no suggestion that BFD should transform the 
> corefile data when it is turned into register data, in fact the oposite 
> is true.  The intent is for just GDB to know how to pack/unpack these 
> regsets and then have BFD, proc, ptrace and the remote target all xfer 
> uninterpreted bytes.  The natural format for those uninterpreted bytes 
> is what ever is specified by the system being debugged.

Eh?

The remote protocol is fixed.  The core file format is fixed.  The
/proc output format is fixed.  They aren't all the same, so I don't
see what this unity would accomplish - they have to be translated
around anyway.

> This would let gdbserver thin down to the point where it only needed to 
> know how to xfer those raw bytes - no need to repack them into a 
> standard G packet.
> 
> Of course a heavy weight gdbserver could also use this regset code to 
> repack bits into G and other packets before shipping them back to GDB.

The lighter-weight version isn't of much interest now - a number of
other issues have convinced me that lightening the stub further isn't
the way to go.

Things like kernel stubs have to convert anyway, since it's a whole
different format.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer