Re: new gdb remote packet type

[Robert Picco <Robert.Picco@hp.com>]

Andrew have you had an opportunity to review this?

thanks,

Bob
Robert Picco wrote:
Andrew Cagney wrote:

Anyway, it sounds like you might (dig dig) be more interested  in the 
attached patch+hack (fernando nasser gets credit for the patch, I 
deny responsibility for the hack bit :-).  It adds a P packet for 
fetching individual registers which is something the existing remote 
protocol spec doco hints at.

Andrew


Seems remote.c currently supports "P" packet for storing a single 
register would you find a patch supporting the "p" packet for fetching 
a single register to be acceptable?  This would put the minimum 
payload on the wire and complement the "P" packet.   It's similar to 
the patch (hack) you forwarded but a complete implementation.

Bob

*** gdb-6.1-orig/gdb/remote.c    2004-02-25 15:41:00.000000000 -0500
--- gdb-6.1/gdb/remote.c    2004-05-06 14:05:47.000000000 -0400
***************
*** 809,814 ****
--- 809,831 ----
   show_packet_config_cmd (&remote_protocol_E);
 }
 
+ static struct packet_config remote_protocol_p;
+ + static void
+ set_remote_protocol_p_packet_cmd (char *args, int from_tty,
+                   struct cmd_list_element *c)
+ {
+   update_packet_config (&remote_protocol_p);
+ }
+ + static void
+ show_remote_protocol_p_packet_cmd (char *args, int from_tty,
+                    struct cmd_list_element *c)
+ {
+   show_packet_config_cmd (&remote_protocol_p);
+ }
+ +  
 /* Should we try the 'P' (set register) request?  */
 
***************
*** 2080,2085 ****
--- 2097,2103 ----
   update_packet_config (&remote_protocol_e);
   update_packet_config (&remote_protocol_E);
   update_packet_config (&remote_protocol_P);
+   update_packet_config (&remote_protocol_p);
   update_packet_config (&remote_protocol_qSymbol);
   update_packet_config (&remote_protocol_vcont);
   for (i = 0; i < NR_Z_PACKET_TYPES; i++)
***************
*** 3240,3245 ****
--- 3258,3293 ----
 /* Read the remote registers into the block REGS.  */
 /* Currently we just read all the registers, so we don't use regnum.  */
 
+ static int
+ fetch_register_using_p (int regnum)
+ {
+   struct remote_state *rs = get_remote_state ();
+   char *buf = alloca (rs->remote_packet_size), *p;
+   char regp[MAX_REGISTER_SIZE];
+   int i;
+ +   buf[0] = 'p';
+   bin2hex((char *) &regnum, &buf[1], sizeof(regnum));
+   buf[9] = 0;
+   remote_send (buf, rs->remote_packet_size);
+   if (buf[0] != 0 && buf[0] != 'E') {
+      p = buf;
+      i = 0;
+      while (p[0] != 0) {
+     if (p[1] == 0) {
+         error("fetch_register_using_p: early buf termination");
+         return 0;
+     }
+     regp[i++] = fromhex (p[0]) * 16 + fromhex (p[1]);
+         p += 2;
+     }
+     regcache_raw_supply (current_regcache, regnum, regp);
+     return 1;
+  }
+ +  return 0;
+ }
+  static void
 remote_fetch_registers (int regnum)
 {
***************
*** 3260,3265 ****
--- 3308,3338 ----
             "Attempt to fetch a non G-packet register when this "
             "remote.c does not support the p-packet.");
     }
+       switch (remote_protocol_p.support)
+     {
+     case PACKET_DISABLE:
+       break;
+     case PACKET_ENABLE:
+       if (fetch_register_using_p (regnum))
+         return;
+       else
+         error ("Protocol error: p packet not recognized by stub");
+     case PACKET_SUPPORT_UNKNOWN:
+       if (fetch_register_using_p (regnum))
+         {
+           /* The stub recognized the 'p' packet.  Remember this.  */
+           remote_protocol_p.support = PACKET_ENABLE;
+           return;
+         }
+       else
+         {
+           /* The stub does not support the 'P' packet.  Use 'G'
+              instead, and don't try using 'P' in the future (it
+              will just waste our time).  */
+           remote_protocol_p.support = PACKET_DISABLE;
+           break;
+         }
+     }
 
   sprintf (buf, "g");
   remote_send (buf, (rs->remote_packet_size));
***************
*** 5419,5424 ****
--- 5492,5498 ----
   show_remote_protocol_e_packet_cmd (args, from_tty, NULL);
   show_remote_protocol_E_packet_cmd (args, from_tty, NULL);
   show_remote_protocol_P_packet_cmd (args, from_tty, NULL);
+   show_remote_protocol_p_packet_cmd (args, from_tty, NULL);
   show_remote_protocol_qSymbol_packet_cmd (args, from_tty, NULL);
   show_remote_protocol_vcont_packet_cmd (args, from_tty, NULL);
   show_remote_protocol_binary_download_cmd (args, from_tty, NULL);
***************
*** 5631,5636 ****
--- 5705,5717 ----
              &remote_set_cmdlist, &remote_show_cmdlist,
              1);
 
+   add_packet_config_cmd (&remote_protocol_p,
+              "p", "fetch-register",
+              set_remote_protocol_p_packet_cmd,
+              show_remote_protocol_p_packet_cmd,
+              &remote_set_cmdlist, &remote_show_cmdlist,
+              1);
+    add_packet_config_cmd (&remote_protocol_Z[Z_PACKET_SOFTWARE_BP],
              "Z0", "software-breakpoint",
              set_remote_protocol_Z_software_bp_packet_cmd,