From ad47d913b54cef188269c4b75fdde51d27d6fe32 Mon Sep 17 00:00:00 2001
From: Doug Goldstein <cardoe@cardoe.com>
Date: Sun, 16 Mar 2014 15:02:59 -0500
Subject: [PATCH] gdb: support reporting memory map locations

GDB wants to have knowledge of the RAM and flash regions of memory on
the chips. Since AVR is Harvard architecture, the RAM must begin at a
fake offset and per Atmel's docs that is 0x800000.
---
 simavr/sim/sim_gdb.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/simavr/sim/sim_gdb.c b/simavr/sim/sim_gdb.c
index a9d4c84..363dbca 100644
--- a/simavr/sim/sim_gdb.c
+++ b/simavr/sim/sim_gdb.c
@@ -288,7 +288,14 @@ gdb_handle_command(
 	uint8_t command = *cmd++;
 	switch (command) {
 		case 'q':
-			if (strncmp(cmd, "Attached", 8) == 0) {
+			if (strncmp(cmd, "Supported", 9) == 0) {
+				/* If GDB asked what features we support, report back
+				 * the features we support, which is just memory layout
+				 * information for now.
+				 */
+				gdb_send_reply(g, "qXfer:memory-map:read+");
+				break;
+			} else if (strncmp(cmd, "Attached", 8) == 0) {
 				/* Respond that we are attached to an existing process..
 				 * ourselves!
 				 */
@@ -297,6 +304,19 @@ gdb_handle_command(
 			} else if (strncmp(cmd, "Offsets", 7) == 0) {
 				gdb_send_reply(g, "Text=0;Data=800000;Bss=800000");
 				break;
+			} else if (strncmp(cmd, "Xfer:memory-map:read", 20) == 0) {
+				snprintf(rep, sizeof(rep),
+						"l<memory-map>\n"
+						" <memory type='ram' start='0x800000' length='%#x'/>\n"
+						" <memory type='flash' start='0' length='%#x'>\n"
+						"  <property name='blocksize'>0x80</property>\n"
+						" </memory>\n"
+						"</memory-map>",
+						g->avr->ramend + 1, g->avr->flashend + 1);
+
+				gdb_send_reply(g, rep);
+				break;
+            }
 			gdb_send_reply(g, "");
 			break;
 		case '?':
-- 
2.39.5