RE: [Patch, microblaze]: Add support of microblaze software single stepping

[Ajit Kumar Agarwal <ajit.kumar.agarwal@xilinx.com>]

PING!

-----Original Message-----
From: Ajit Kumar Agarwal 
Sent: Friday, June 20, 2014 11:40 AM
To: 'gdb-patches@sourceware.org'
Cc: 'Michael Eager'; 'Pedro Alves'; Vinod Kathail; Vidhumouli Hunsigida; Nagaraju Mekala
Subject: RE: [Patch, microblaze]: Add support of microblaze software single stepping

Please find the patch that supports the microblaze software single stepping. This patch handles the cases of branch and return with delay slot
and the imm instruction in microblaze. Could you please review and let me know if its okay.   

 [Patch, microblaze]: Add support of microblaze software single stepping
    
    This patch adds the support of microblaze software single stepping. It
    handles the cases of branch and return with delay slot and imm instruction
    in microblaze.
    
    ChangeLog:
    2014-06-19 Ajit Agarwal <ajitkum@xilinx.com>
    
        * microblaze-tdep.c (microblaze_software_single_step): New.
        (microblaze_gdbarch_init): Use of set_gdbarch_software_single_step.
    
    Signed-off-by:Ajit Agarwal ajitkum@xilinx.com

---
 gdb/microblaze-tdep.c |   79 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/gdb/microblaze-tdep.c b/gdb/microblaze-tdep.c index 14c1b52..3de2f70 100644
--- a/gdb/microblaze-tdep.c
+++ b/gdb/microblaze-tdep.c
@@ -628,6 +628,83 @@ microblaze_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
   return (TYPE_LENGTH (type) == 16);
 }
 
+static int
+microblaze_software_single_step (struct frame_info *frame) {
+  struct gdbarch *arch = get_frame_arch (frame);
+  struct address_space *aspace = get_frame_address_space (frame);
+  struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
+  enum bfd_endian byte_order = gdbarch_byte_order (arch);
+  int ret = 0;
+  int ii;
+  CORE_ADDR pc;
+  long insn;
+  enum microblaze_instr minstr;
+  bfd_boolean isunsignednum;
+  enum microblaze_instr_type insn_type;
+  short delay_slots;
+  int imm;
+  bfd_boolean immfound = FALSE;
+  CORE_ADDR breaks[2] = {-1,-1};
+  CORE_ADDR address;
+  int targetvalid;
+
+  /* Set a breakpoint at the next instruction  */
+  /* If the current instruction is an imm, set it at the inst after  */
+  /* If the instruction has a delay slot, skip the delay slot  */  pc = 
+ get_frame_pc (frame);  insn = microblaze_fetch_instruction (pc);  
+ minstr = get_insn_microblaze (insn, &isunsignednum, &insn_type, 
+ &delay_slots);  if (insn_type == immediate_inst)
+    { 
+      int rd, ra, rb; 
+      immfound = TRUE; 
+      minstr = microblaze_decode_insn (insn, &rd, &ra, &rb, &imm); 
+      pc = pc + INST_WORD_SIZE; 
+      insn = microblaze_fetch_instruction (pc); 
+      minstr = get_insn_microblaze (insn, &isunsignednum, &insn_type, &delay_slots); 
+    }   
+  if (insn_type != return_inst) 
+    breaks[0] = pc + delay_slots * INST_WORD_SIZE + INST_WORD_SIZE;
+    
+  /* Now check for branch or return instructions  */  if (insn_type == 
+ branch_inst || insn_type == return_inst)
+    { 
+      int limm; 
+      int lrd, lra, lrb; 
+      int ra, rb; 
+      bfd_boolean targetvalid; 
+      bfd_boolean unconditionalbranch; 
+      microblaze_decode_insn (insn, &lrd, &lra, &lrb, &limm); 
+      if (lra >= 0 && lra < MICROBLAZE_NUM_REGS) 
+        ra = get_frame_register_unsigned (frame, lra); 
+      else 
+        ra = 0; 
+      if (lrb >= 0 && lrb < MICROBLAZE_NUM_REGS) 
+        rb = get_frame_register_unsigned (frame, lrb); 
+      else 
+        rb = 0; 
+      address = microblaze_get_target_address (insn, immfound, imm, pc, 
+ ra, rb, &targetvalid, &unconditionalbranch);
+        
+      if (!unconditionalbranch) 
+        breaks[1] = address;
+    }
+    
+  /* Insert the breakpoints  */
+   if (breaks[0] != -1) 
+     {
+       insert_single_step_breakpoint (arch, aspace, breaks[0]); 
+       ret = 1; 
+     }
+  if (breaks[1] != -1) 
+    {   
+      insert_single_step_breakpoint (arch, aspace, breaks[1]);     
+      ret = 1;  
+    }
+
+  return ret;
+}
+ 
 static void
 microblaze_write_pc (struct regcache *regcache, CORE_ADDR pc)  { @@ -708,6 +785,8 @@ microblaze_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   set_gdbarch_breakpoint_from_pc (gdbarch, microblaze_breakpoint_from_pc);
 
+  set_gdbarch_software_single_step (gdbarch, 
+ microblaze_software_single_step);
+
   set_gdbarch_frame_args_skip (gdbarch, 8);
 
   set_gdbarch_print_insn (gdbarch, print_insn_microblaze);
--
1.7.1

Thanks & Regards
Ajit