RE: [Patch, microblaze]: Fix for remote G Packet message too long error for baremetal.

[Ajit Kumar Agarwal <ajit dot kumar dot agarwal at xilinx dot com>]

Based on feedback, review comments are incorporated. Could you please review
and let me know if its okay.

    [Patch, microblaze]: Fix for remote G Packet message too long error for baremetal.
    
    Prior to version MicroBlaze v8.10.a,EDK 13.1, XMD's gdbserver stub returned 57
    registers in response to GDB's G request.  Starting with version MicroBlaze
    v8.10.a, EDK 13.1, XMD added the slr and shr register, for a count of 59
    registers.This patch adds these registers to the expected G response. This patch
    fixes the above problem for baremetal and also supports the backward compatibility.
    
    ChangeLog:
    2014-06-19 Ajit Agarwal <ajitkum@xilinx.com>
    
        * microblaze-tdep.c (microblaze_register_names): Add
        the rshr and rslr register names.
        (microblaze_gdbarch_init): Use of tdesc_has_registers.
        Use of tdesc_find_feature. Use of tdesc_data_alloc.
        Use of tdesc_numbered_register. Use of
        microblaze_register_g_packet_guesses. Use of
        tdesc_use_registers. Use of set_gdbarch_register_type.
        (microblaze_register_g_packet_guesses): New.
        * microblaze-tdep.h (microblaze_reg_num): Add
        field MICROBLAZE_SLR_REGNUM MICROBLAZE_SHR_REGNUM
        MICROBLAZE_NUM_REGS and MICROBLAZE_NUM_CORE_REGS.
        (microblaze_frame_cache): Use of MICROBLAZE_NUM_REGS.
        * features/microblaze-core.xml: New file.
        * features/microblaze-stack-protect.xml: New file.
        * features/microblaze-with-stack-protect.c: New file.
        * features/microblaze-with-stack-protect.xml: New file.
        * features/microblaze.xml: New file.
        * features/microblaze.c: New file.
        * features/Makefile (microblaze-linux): Add
        microblaze-linux microblaze and microblaze-expedite.
        * regformats/microblaze-with-stack-protect.dat: New file.
        * regformats/microblaze.dat: New file.
    
    Signed-off-by:Ajit Agarwal ajitkum@xilinx.com

-----Original Message-----
From: Ajit Kumar Agarwal 
Sent: Wednesday, June 18, 2014 9:28 PM
To: 'Pedro Alves'
Cc: gdb-patches@sourceware.org; Michael Eager; Vinod Kathail; Vidhumouli Hunsigida; Nagaraju Mekala
Subject: RE: [Patch, microblaze]: Fix for remote G Packet message too long error for baremetal.


Thanks for the clarifications and comments. I will incorporate the change.

Thanks & Regards
Ajit
-----Original Message-----
From: Pedro Alves [mailto:palves@redhat.com]
Sent: Wednesday, June 18, 2014 9:24 PM
To: Ajit Kumar Agarwal
Cc: gdb-patches@sourceware.org; Michael Eager; Vinod Kathail; Vidhumouli Hunsigida; Nagaraju Mekala
Subject: Re: [Patch, microblaze]: Fix for remote G Packet message too long error for baremetal.

On 06/18/2014 04:39 PM, Ajit Kumar Agarwal wrote:

> The info registers against such a  stub( where the design does not 
> have stack-protect registers) shows the registers $rshr and $rslr but 
> it shows as <unavailable>.  Is the display of $rshr and $rslr 
> happening because of this second guess with -2 case?

Yes, because you're guessing a target description that includes the registers.

Is it inappropriate to have the second guess with -2 case?

It is, but you're guessing the wrong description...

In addition to tdesc_microblaze_with_stack_protect, create _another_ description that does _not_ xi:include the stack protect feature, and register the guess with that:

microblaze_register_g_packet_guesses (struct gdbarch *gdbarch) {
  register_remote_g_packet_guess (gdbarch,
				  MICROBLAZE_NUM_REGS,
                                  tdesc_microblaze_with_stack_protect);

  register_remote_g_packet_guess (gdbarch,
                                  MICROBLAZE_NUM_REGS - 2,
                                  tdesc_microblaze); }

I'd add a MICROBLAZE_NUM_CORE_REGS value to the registers enum.  Then instead of that magic " - 2", you could write:

{
  register_remote_g_packet_guess (gdbarch,
				  MICROBLAZE_NUM_CORE_REGS,
                                  tdesc_microblaze);

  register_remote_g_packet_guess (gdbarch,
                                  MICROBLAZE_NUM_REGS,
                                  tdesc_microblaze_with_stack_protect);

--
Pedro Alves

Attachment: 0001-Patch-microblaze-Fix-for-remote-G-Packet-message-too.patch
Description: 0001-Patch-microblaze-Fix-for-remote-G-Packet-message-too.patch