memwatch - read memory while running

src/Makefile

@@ -56,6 +56,7 @@ SRC =              \
 	kinetis.c      \
 	main.c         \
 	maths_utils.c  \
+	memwatch.c     \
 	morse.c        \
 	msp432e4.c     \
 	msp432p4.c     \

src/command.c

@@ -37,6 +37,7 @@
 #include "serialno.h"
 #include "jtagtap.h"
 #include "jtag_scan.h"
+#include "memwatch.h"
 
 #ifdef ENABLE_RTT
 #include "rtt.h"
@@ -52,6 +53,8 @@
 #include <alloca.h>
 #endif
 
+#include <ctype.h>
+
 static bool cmd_version(target_s *t, int argc, const char **argv);
 static bool cmd_help(target_s *t, int argc, const char **argv);
 
@@ -72,6 +75,7 @@ static bool cmd_target_power(target_s *t, int argc, const char **argv);
 static bool cmd_traceswo(target_s *t, int argc, const char **argv);
 #endif
 static bool cmd_heapinfo(target_s *t, int argc, const char **argv);
+static bool cmd_memwatch(target_s *t, int argc, const char **argv);
 #ifdef ENABLE_RTT
 static bool cmd_rtt(target_s *t, int argc, const char **argv);
 #endif
@@ -112,6 +116,7 @@ const command_s cmd_list[] = {
 	{"traceswo", cmd_traceswo, "Start trace capture, Manchester mode: [decode [CHANNEL_NR ...]]"},
 #endif
 #endif
+	{"memwatch", cmd_memwatch, "Print memory changes: [[NAME] [/d|/u|/x] ADDRESS]..."},
 	{"heapinfo", cmd_heapinfo, "Set semihosting heapinfo: HEAPINFO HEAP_BASE HEAP_LIMIT STACK_BASE STACK_LIMIT"},
 #if defined(PLATFORM_HAS_DEBUG) && PC_HOSTED == 0
 	{"debug_bmp", cmd_debug_bmp, "Output BMP \"debug\" strings to the second vcom: [enable|disable]"},
@@ -670,6 +675,61 @@ static bool cmd_shutdown_bmda(target_s *t, int argc, const char **argv)
 }
 #endif
 
+static bool cmd_memwatch(target_s *t, int argc, const char **argv)
+{
+	memwatch_format_e fmt = MEMWATCH_FMT_HEX;
+	char name[MEMWATCH_STRLEN] = {0};
+	(void)t;
+	memset(memwatch_table, 0, sizeof(memwatch_table));
+	memwatch_cnt = 0;
+	for (int32_t i = 1; i < argc; i++) {
+		if (argv[i][0] == '/') {
+			/* format follows */
+			switch (argv[i][1]) {
+			case 'd':
+				fmt = MEMWATCH_FMT_SIGNED;
+				break;
+			case 'u':
+				fmt = MEMWATCH_FMT_UNSIGNED;
+				break;
+			case 'x':
+				fmt = MEMWATCH_FMT_HEX;
+				break;
+			default:
+				break;
+			}
+		} else if (isalpha(argv[i][0])) {
+			/* name  follows */
+			strncpy(name, argv[i], sizeof(name));
+			name[sizeof(name) - 1] = '\0';
+		} else if (isdigit(argv[i][0])) {
+			/* address follows */
+			uint32_t addr = strtoul(argv[i], NULL, 0);
+			if (name[0] == '\0') {
+				/* no name given, use address as name */
+				snprintf(name, MEMWATCH_STRLEN, "0x%08" PRIx32, addr);
+				name[MEMWATCH_STRLEN - 1] = '\0';
+			}
+
+			/* add new name, format and address to memwatch table */
+			memwatch_table[memwatch_cnt].addr = addr;
+			memwatch_table[memwatch_cnt].value = 0xdeadbeef;
+			memwatch_table[memwatch_cnt].format = fmt;
+			memcpy(memwatch_table[memwatch_cnt].name, name, MEMWATCH_STRLEN);
+			memwatch_cnt++;
+			memset(name, 0, sizeof(name));
+			gdb_outf("0x%x ", addr);
+			if (memwatch_cnt == MEMWATCH_NUM)
+				break;
+		} else {
+			gdb_outf("?");
+			break;
+		}
+	}
+	gdb_outf("\n");
+	return true;
+}
+
 static bool cmd_heapinfo(target_s *t, int argc, const char **argv)
 {
 	if (t == NULL)

src/include/memwatch.h

@@ -0,0 +1,29 @@
+#ifndef MEMWATCH_H
+#define MEMWATCH_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <target.h>
+
+#define MEMWATCH_NUM 8
+/* string length has to be long enough to store an address 0x20000000 */
+#define MEMWATCH_STRLEN 12
+
+typedef enum memwatch_format {
+	MEMWATCH_FMT_SIGNED,
+	MEMWATCH_FMT_UNSIGNED,
+	MEMWATCH_FMT_HEX
+} memwatch_format_e;
+
+typedef struct {
+	uint32_t addr;
+	uint32_t value;
+	char name[MEMWATCH_STRLEN];
+	memwatch_format_e format;
+} memwatch_s;
+
+extern memwatch_s memwatch_table[MEMWATCH_NUM];
+extern uint32_t memwatch_cnt;
+extern void poll_memwatch(target_s *cur_target);
+
+#endif

src/main.c

@@ -29,6 +29,7 @@
 #include "gdb_packet.h"
 #include "morse.h"
 #include "command.h"
+#include "memwatch.h"
 #ifdef ENABLE_RTT
 #include "rtt.h"
 #endif
@@ -59,6 +60,8 @@ static void bmp_poll_loop(void)
 		if (rtt_enabled)
 			poll_rtt(cur_target);
 #endif
+		if (memwatch_cnt != 0)
+			poll_memwatch(cur_target);
 	}
 
 	SET_IDLE_STATE(true);

src/memwatch.c

@@ -0,0 +1,46 @@
+#include "general.h"
+#include "gdb_packet.h"
+#include "memwatch.h"
+#if PC_HOSTED == 1
+#include <unistd.h>
+#else
+#include "usb_serial.h"
+#endif
+
+memwatch_s memwatch_table[MEMWATCH_NUM];
+uint32_t memwatch_cnt = 0;
+
+void poll_memwatch(target_s *cur_target)
+{
+	uint32_t val;
+	char buf[64];
+	uint32_t len;
+	if (!cur_target || (memwatch_cnt == 0))
+		return;
+
+	for (uint32_t i = 0; i < memwatch_cnt; i++) {
+		if (!target_mem_read(cur_target, &val, memwatch_table[i].addr, sizeof(val)) &&
+			(val != memwatch_table[i].value)) {
+			switch (memwatch_table[i].format) {
+			case MEMWATCH_FMT_SIGNED:
+				len = snprintf(buf, sizeof(buf), "%s: %" PRId32 "\r\n", memwatch_table[i].name, val);
+				break;
+			case MEMWATCH_FMT_UNSIGNED:
+				len = snprintf(buf, sizeof(buf), "%s: %" PRIu32 "\r\n", memwatch_table[i].name, val);
+				break;
+			case MEMWATCH_FMT_HEX:
+			default:
+				len = snprintf(buf, sizeof(buf), "%s: 0x%" PRIx32 "\r\n", memwatch_table[i].name, val);
+				break;
+			}
+#if PC_HOSTED == 1
+			int l = write(1, buf, len);
+			(void)l;
+#else
+			debug_serial_fifo_send(buf, 0, len);
+#endif
+			memwatch_table[i].value = val;
+		}
+	}
+	return;
+}