Re: gdb-h8-stub

[Daniel Jacobowitz <drow@mvista.com>]

On Thu, Jul 18, 2002 at 11:00:19PM -0700, Alexei Minayev wrote:
> Hi Daniel,
> 
> thanks for an interesting discussion.
> 
> --- Daniel Jacobowitz <drow@mvista.com> wrote:
> > On Thu, Jul 18, 2002 at 11:25:50AM -0700, Alexei Minayev wrote:
> > > X200000
> > > M0,15:...    ; (this would actually mean 0x200000 to 0x200015)
> > > M15,15:...
> > > M30,15:...
> > > ...
> > > 
> > > So according to this, the stub *must* read the address from the X command
> and
> > > store it for future memory operations, even if it doesn't support binary
> > > downloads. 
> > > In your opinion, is that what gdb means?
> > 
> > No, what I'm trying to say is that that's the wrong behavior for the
> > client.  You'll need to figure out why GDB is doing this.
> > 
> it might have been the wrong behavior for the client... but it's a very
> standard client code, working in many stubs. 
> The stub code, in particular, when parsing an 'M' command, is looking for an
> *absolute* address. But the gdb sends relative addresses to him.
> I mean, what could the client possibly say wrong, that gdb chooses a totally
> different way of communication?
> 
> I went ahead and implemented binary downloading. 
> Still:
> X200000,0...Ack
> X0,4e...Ack           (I'd expect X200000,4e here)
> Packet received: OK
> X4e,4e...Ack          (expected: X20004e,4e)
> Packet received: OK
> and so on.
> 
> Address is *relative* to what comes in the first packet. E.g. the second
> packet gdb sends is "X0", which means "0 bytes +0x200000 base", and the base
> value was in the first packet.
> 
> Am I forgetting some option or variable?

The test for the X packet is missing something that is present in
normal use:

  memaddr = remote_address_masked (memaddr);
  p += hexnumstr (p, (ULONGEST) memaddr);
  *p++ = ',';


You have TARGET_ADDR_BIT set too small for your port.  You are probably
confusing TARGET_PTR_BIT (the number of bits in a pointer, which can
have some separate space marker not included in this count) and
TARGET_ADDR_BIT (the number of bits to correctly identify an address
when dealing with the OS or stub).

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer