log_rpc: replace crash log with crash dump

Replace a custom solution for storing crash log in retained
RAM and exposing it in as a string over RPC with Zephyr
Core Dump module. In the latter solution RPC is only used
to fetch the crash dump to the remote device.

Signed-off-by: Damian Krolik <[email protected]>

Author: Damian-Nordic

include/logging/log_rpc.h

@@ -143,13 +143,13 @@ int log_rpc_fetch_history(log_rpc_history_handler_t handler);
 void log_rpc_stop_fetch_history(bool pause);
 
 /**
- * @brief Retrieves the crash log retained on the remote device.
+ * @brief Retrieves the crash dump saved on the remote device.
  *
- * This function issues an nRF RPC command to obtain the last crash log retained
- * on the remote device, and then it copies the received log chunk into the
- * specified buffer.
+ * This function issues an nRF RPC command to obtain a subsequent chunk of the
+ * last crash dump saved on the remote device, and then it puts the received
+ * chunk into the provided buffer.
  *
- * The remote may either send the entire crash log in one go, if it fits within
+ * The remote may either send the entire dump in one go, if it fits within
  * the output buffer, or it may send a chunk of the log. Therefore, the caller
  * should repeatedly call this function, with an increasing offset, until it
  * returns 0 (indicating no more data), or a negative value (indicated an error).
@@ -161,7 +161,7 @@ void log_rpc_stop_fetch_history(bool pause);
  * @returns             The number of characters copied into the output buffer.
  * @returns -errno      Indicates failure.
  */
-int log_rpc_get_crash_log(size_t offset, char *buffer, size_t buffer_length);
+int log_rpc_get_crash_dump(size_t offset, uint8_t *buffer, size_t buffer_length);
 
 /**
  * @brief Generates a log message on the remote device.

samples/nrf_rpc/protocols_serialization/client/src/log_rpc_shell.c

@@ -8,9 +8,15 @@
 
 #include <zephyr/kernel.h>
 #include <zephyr/shell/shell.h>
+#include <zephyr/sys/util.h>
 
 #include <stdlib.h>
 
+#define COREDUMP_LOG_PREFIX   "#CD:"
+#define COREDUMP_LOG_BEGIN    "BEGIN#"
+#define COREDUMP_LOG_END      "END#"
+#define COREDUMP_LOG_LINE_LEN 32
+
 static int cmd_log_rpc_stream_level(const struct shell *sh, size_t argc, char *argv[])
 {
 	int rc = 0;
@@ -143,19 +149,26 @@ static int cmd_log_rpc_crash(const struct shell *sh, size_t argc, char *argv[])
 {
 	int rc;
 	char buffer[CONFIG_RPC_CRASH_LOG_READ_BUFFER_SIZE];
+	char line[COREDUMP_LOG_LINE_LEN * 2 + 1];
 	size_t offset = 0;
 
+	shell_print(sh, COREDUMP_LOG_PREFIX COREDUMP_LOG_BEGIN);
+
 	while (true) {
-		rc = log_rpc_get_crash_log(offset, buffer, sizeof(buffer));
+		rc = log_rpc_get_crash_dump(offset, buffer, sizeof(buffer));
 		if (rc <= 0) {
 			break;
 		}
 
-		shell_fprintf(sh, SHELL_NORMAL, "%.*s", (size_t)rc, buffer);
+		for (int i = 0; i < rc; i += COREDUMP_LOG_LINE_LEN) {
+			bin2hex(&buffer[i], MIN(COREDUMP_LOG_LINE_LEN, rc - i), line, sizeof(line));
+			shell_print(sh, COREDUMP_LOG_PREFIX "%s", line);
+		}
+
 		offset += (size_t)rc;
 	}
 
-	shell_fprintf(sh, SHELL_NORMAL, "\n");
+	shell_print(sh, COREDUMP_LOG_PREFIX COREDUMP_LOG_END);
 
 	if (rc) {
 		shell_error(sh, "Error: %d", rc);

samples/nrf_rpc/protocols_serialization/server/pm_static_nrf52840dk_nrf52840.yml

@@ -0,0 +1,4 @@
+coredump_partition:
+  region: flash_primary
+  address: 0xfd000
+  size: 0x3000

samples/nrf_rpc/protocols_serialization/server/pm_static_nrf54l15dk_nrf54l15_cpuapp.yml

@@ -0,0 +1,4 @@
+coredump_partition:
+  region: flash_primary
+  address: 0x17a000
+  size: 0x3000

samples/nrf_rpc/protocols_serialization/server/snippets/log_rpc/boards/nrf52840dk_nrf52840.overlay

@@ -10,6 +10,13 @@ CONFIG_LOG_BACKEND_RPC_CRASH_LOG=y
 CONFIG_LOG_BACKEND_RPC_HISTORY=y
 CONFIG_LOG_BACKEND_RPC_ECHO=y
 
+# Save core dump to flash partition
+CONFIG_DEBUG_COREDUMP=y
+CONFIG_DEBUG_COREDUMP_BACKEND_OTHER=y
+CONFIG_DEBUG_COREDUMP_BACKEND_NRF_FLASH_PARTITION=y
+CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y
+CONFIG_DEBUG_COREDUMP_THREADS_METADATA=n
+
 # nRF RPC requires slightly bigger stack than default
 CONFIG_LOG_PROCESS_THREAD_STACK_SIZE=1024
 

samples/nrf_rpc/protocols_serialization/server/snippets/log_rpc/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -7,11 +7,3 @@
 name: log_rpc
 append:
   EXTRA_CONF_FILE: log_rpc.conf
-
-boards:
-  nrf52840dk/nrf52840:
-    append:
-      EXTRA_DTC_OVERLAY_FILE: boards/nrf52840dk_nrf52840.overlay
-  nrf54l15dk/nrf54l15/cpuapp:
-    append:
-      EXTRA_DTC_OVERLAY_FILE: boards/nrf54l15dk_nrf54l15_cpuapp.overlay

samples/nrf_rpc/protocols_serialization/server/snippets/log_rpc/log_rpc.conf

@@ -88,10 +88,7 @@ endif # LOG_BACKEND_RPC_HISTORY
 
 config LOG_BACKEND_RPC_CRASH_LOG
 	bool "Crash log support"
-	select RETENTION
-	select RETENTION_MUTEX_FORCE_DISABLE
-	select RETAINED_MEM
-	select RETAINED_MEM_MUTEX_FORCE_DISABLE
+	depends on DEBUG_COREDUMP
 	help
 	  Enables saving the crash log in the "crash_log" retained RAM partition,
 	  and adds an nRF RPC command that allows a remote user to read the crash