mgmt: mcumgr: grp: os_mgmt: Add memory pool statistics command support

include/zephyr/mgmt/mcumgr/grp/os_mgmt/os_mgmt.h

@@ -61,6 +61,9 @@ enum os_mgmt_err_code_t {
 
 	/** Query was recognized but there is no valid value for the response. */
 	OS_MGMT_ERR_QUERY_RESPONSE_VALUE_NOT_VALID,
+
+	/** Heap statistic fetch failed. */
+	OS_MGMT_ERR_HEAP_STATS_FETCH_FAILED,
 };
 
 /**

subsys/mgmt/mcumgr/grp/img_mgmt/src/img_mgmt.c

@@ -130,22 +130,6 @@ void img_mgmt_release_lock(void)
 #endif
 }
 
-#if defined(CONFIG_MCUMGR_GRP_IMG_SLOT_INFO_HOOKS)
-static bool img_mgmt_reset_zse(struct smp_streamer *ctxt)
-{
-	zcbor_state_t *zse = ctxt->writer->zs;
-
-	/* Because there is already data in the buffer, it must be cleared first */
-	net_buf_reset(ctxt->writer->nb);
-	ctxt->writer->nb->len = sizeof(struct smp_hdr);
-	zcbor_new_encode_state(zse, ARRAY_SIZE(ctxt->writer->zs),
-			       ctxt->writer->nb->data + sizeof(struct smp_hdr),
-			       net_buf_tailroom(ctxt->writer->nb), 0);
-
-	return zcbor_map_start_encode(zse, CONFIG_MCUMGR_SMP_CBOR_MAX_MAIN_MAP_ENTRIES);
-}
-#endif
-
 #if defined(CONFIG_MCUMGR_GRP_IMG_TOO_LARGE_SYSBUILD)
 static bool img_mgmt_slot_max_size(size_t *area_sizes, zcbor_state_t *zse)
 {
@@ -597,7 +581,7 @@ static int img_mgmt_slot_info(struct smp_streamer *ctxt)
 					return err_rc;
 				}
 
-				ok = img_mgmt_reset_zse(ctxt) &&
+				ok = smp_mgmt_reset_zse(ctxt) &&
 				     smp_add_cmd_err(zse, err_group, (uint16_t)err_rc);
 
 				goto finish;
@@ -645,7 +629,7 @@ static int img_mgmt_slot_info(struct smp_streamer *ctxt)
 					return err_rc;
 				}
 
-				ok = img_mgmt_reset_zse(ctxt) &&
+				ok = smp_mgmt_reset_zse(ctxt) &&
 				     smp_add_cmd_err(zse, err_group, (uint16_t)err_rc);
 
 				goto finish;

subsys/mgmt/mcumgr/grp/os_mgmt/Kconfig

@@ -137,6 +137,26 @@ config MCUMGR_GRP_OS_TASKSTAT_STACK_INFO
 
 endif
 
+config MCUMGR_GRP_OS_MPSTAT
+	bool "Support for memory pool statistics command"
+	depends on SYS_HEAP_RUNTIME_STATS
+	depends on SYS_HEAP_ARRAY_SIZE > 0
+	select MCUMGR_SMP_CBOR_MIN_ENCODING_LEVEL_2
+	select MCUMGR_SMP_CBOR_MIN_ENCODING_LEVEL_3 if ZCBOR_CANONICAL
+	help
+	  The memory pool statistics (mpstat) command will list the various heap memory pools
+	  on the device, including sizes, free space and minimum amount of free space.
+
+config MCUMGR_GRP_OS_MPSTAT_ONLY_SUPPORTED_STATS
+	bool "Send only data gathered by Zephyr"
+	depends on MCUMGR_GRP_OS_MPSTAT
+	default y
+	help
+	  Response will not include the "blksiz" field which Zephyr does not support (as it has a
+	  value of 1). Enable this if your client software is able to process "mpstat" response
+	  without the "blksiz" field for each memory pool. Enabling this option will slightly
+	  reduce code size.
+
 config MCUMGR_GRP_OS_ECHO
 	bool "Support for echo command"
 	default y

subsys/mgmt/mcumgr/grp/os_mgmt/src/os_mgmt.c

@@ -25,6 +25,11 @@
 
 #include <mgmt/mcumgr/util/zcbor_bulk.h>
 
+#ifdef CONFIG_MCUMGR_GRP_OS_MPSTAT
+#include <zephyr/sys/sys_heap.h>
+#include <mgmt/mcumgr/transport/smp_internal.h>
+#endif
+
 #ifdef CONFIG_REBOOT
 #include <zephyr/sys/reboot.h>
 #endif
@@ -145,6 +150,22 @@ struct datetime_parser {
 extern uint8_t *MCUMGR_GRP_OS_INFO_BUILD_DATE_TIME;
 #endif
 
+#ifdef CONFIG_MCUMGR_GRP_OS_MPSTAT
+/* Specifies the maximum characters in the memory pool ID, allowing up to 999 outputs */
+#define MPSTAT_ID_KEY_SIZE 4
+
+#ifdef CONFIG_MCUMGR_GRP_OS_MPSTAT_ONLY_SUPPORTED_STATS
+/* Number of items per memory pool output */
+#define MPSTAT_KEY_MAP_ENTRIES 3
+#else
+/* Number of items per memory pool output */
+#define MPSTAT_KEY_MAP_ENTRIES 4
+
+/* Specifies the block size of memory pools, zephyr used byte-level allocation */
+#define MPSTAT_BLOCK_SIZE 1
+#endif
+#endif
+
 /**
  * Command handler: os echo
  */
@@ -355,6 +376,76 @@ static int os_mgmt_taskstat_read(struct smp_streamer *ctxt)
 }
 #endif /* CONFIG_MCUMGR_GRP_OS_TASKSTAT */
 
+#ifdef CONFIG_MCUMGR_GRP_OS_MPSTAT
+/**
+ * Command handler: os mpstat
+ */
+static int os_mgmt_mpstat_read(struct smp_streamer *ctxt)
+{
+	zcbor_state_t *zse = ctxt->writer->zs;
+	struct sys_heap **heap;
+	uint8_t key[MPSTAT_ID_KEY_SIZE] = { 0 };
+	int heap_elements;
+	int i = 0;
+	bool ok;
+
+	heap_elements = sys_heap_array_get(&heap);
+	ok = zcbor_tstr_put_lit(zse, "tasks") &&
+	     zcbor_map_start_encode(zse, heap_elements);
+
+	if (!ok) {
+		goto end;
+	}
+
+	while (i < heap_elements) {
+		struct sys_memory_stats heap_stats;
+		uint32_t heap_total_size;
+		int rc;
+		uint8_t key_size;
+
+		rc = sys_heap_runtime_stats_get(heap[i], &heap_stats);
+
+		if (rc != 0) {
+			ok = smp_mgmt_reset_zse(ctxt) &&
+			     smp_add_cmd_err(zse, MGMT_GROUP_ID_OS,
+					     OS_MGMT_ERR_HEAP_STATS_FETCH_FAILED);
+			LOG_ERR("Failed to get heap stats from address %p: %d", heap[i], rc);
+			goto end;
+		}
+
+		key_size = u8_to_dec(key, sizeof(key), i);
+		heap_total_size = heap_stats.allocated_bytes + heap_stats.free_bytes;
+
+		ok = zcbor_tstr_encode_ptr(zse, key, (size_t)key_size) &&
+		     zcbor_map_start_encode(zse, MPSTAT_KEY_MAP_ENTRIES) &&
+#ifndef CONFIG_MCUMGR_GRP_OS_MPSTAT_ONLY_SUPPORTED_STATS
+		     zcbor_tstr_put_lit(zse, "blksiz") &&
+		     zcbor_uint32_put(zse, MPSTAT_BLOCK_SIZE) &&
+#endif
+		     zcbor_tstr_put_lit(zse, "nblks") &&
+		     zcbor_uint32_put(zse, heap_total_size) &&
+		     zcbor_tstr_put_lit(zse, "nfree") &&
+		     zcbor_uint32_put(zse, heap_stats.free_bytes) &&
+		     zcbor_tstr_put_lit(zse, "min") &&
+		     zcbor_uint32_put(zse, (heap_total_size - heap_stats.max_allocated_bytes)) &&
+		     zcbor_map_end_encode(zse, MPSTAT_KEY_MAP_ENTRIES);
+
+		if (!ok) {
+			break;
+		}
+
+		++i;
+	}
+
+	if (ok == true) {
+		ok = zcbor_map_end_encode(zse, heap_elements);
+	}
+
+end:
+	return MGMT_RETURN_CHECK(ok);
+}
+#endif /* CONFIG_MCUMGR_GRP_OS_MPSTAT */
+
 #ifdef CONFIG_REBOOT
 /**
  * Command handler: os reset
@@ -1117,6 +1208,7 @@ static int os_mgmt_translate_error_code(uint16_t err)
 	case OS_MGMT_ERR_QUERY_YIELDS_NO_ANSWER:
 	case OS_MGMT_ERR_RTC_NOT_SET:
 	case OS_MGMT_ERR_QUERY_RESPONSE_VALUE_NOT_VALID:
+	case OS_MGMT_ERR_HEAP_STATS_FETCH_FAILED:
 		rc = MGMT_ERR_ENOENT;
 		break;
 
@@ -1142,6 +1234,12 @@ static const struct mgmt_handler os_mgmt_group_handlers[] = {
 	},
 #endif
 
+#ifdef CONFIG_MCUMGR_GRP_OS_MPSTAT
+	[OS_MGMT_ID_MPSTAT] = {
+		os_mgmt_mpstat_read, NULL
+	},
+#endif
+
 #ifdef CONFIG_MCUMGR_GRP_OS_DATETIME
 	[OS_MGMT_ID_DATETIME_STR] = {
 		os_mgmt_datetime_read, os_mgmt_datetime_write

subsys/mgmt/mcumgr/transport/include/mgmt/mcumgr/transport/smp_internal.h

@@ -11,7 +11,9 @@
 #include <stdint.h>
 #include <zephyr/kernel.h>
 #include <zephyr/net_buf.h>
+#include <zephyr/mgmt/mcumgr/smp/smp.h>
 #include <zephyr/mgmt/mcumgr/transport/smp.h>
+#include <zcbor_encode.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -79,6 +81,30 @@ void *smp_alloc_rsp(const void *req, void *arg);
  */
 void smp_free_buf(void *buf, void *arg);
 
+/**
+ * @brief	Reeset a zcbor encoder to allow a new response.
+ *
+ * If a response has already been (partially) generated than this will allow resetting back to
+ * the default state so that new response can be used (e.g. an error).
+ *
+ * @param streamer	The streamer providing the required SMP callbacks.
+ *
+ * @return	true on success, false on failure (memory error).
+ */
+static inline bool smp_mgmt_reset_zse(struct smp_streamer *streamer)
+{
+	zcbor_state_t *zse = streamer->writer->zs;
+
+	/* Because there is already data in the buffer, it must be cleared first */
+	net_buf_reset(streamer->writer->nb);
+	streamer->writer->nb->len = sizeof(struct smp_hdr);
+	zcbor_new_encode_state(zse, ARRAY_SIZE(streamer->writer->zs),
+			       streamer->writer->nb->data + sizeof(struct smp_hdr),
+			       net_buf_tailroom(streamer->writer->nb), 0);
+
+	return zcbor_map_start_encode(zse, CONFIG_MCUMGR_SMP_CBOR_MAX_MAIN_MAP_ENTRIES);
+}
+
 #ifdef __cplusplus
 }
 #endif

tests/subsys/mgmt/mcumgr/os_mgmt_mpstat/CMakeLists.txt

@@ -0,0 +1,14 @@
+#
+# Copyright (c) 2023 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(os_mgmt_mpstat)
+
+FILE(GLOB app_sources src/*.c)
+
+target_sources(app PRIVATE ${app_sources})
+target_include_directories(app PRIVATE ${ZEPHYR_BASE}/subsys/mgmt/mcumgr/transport/include/mgmt/mcumgr/transport/)

tests/subsys/mgmt/mcumgr/os_mgmt_mpstat/prj.conf

@@ -0,0 +1,24 @@
+#
+# Copyright (c) 2025 Jamie McCrae
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+CONFIG_ZTEST=y
+CONFIG_NET_BUF=y
+CONFIG_BASE64=y
+CONFIG_ZCBOR=y
+CONFIG_CRC=y
+CONFIG_MINIMAL_LIBC=y
+CONFIG_COMMON_LIBC_MALLOC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=1024
+CONFIG_HEAP_MEM_POOL_SIZE=256
+CONFIG_SYS_HEAP_RUNTIME_STATS=y
+CONFIG_SYS_HEAP_ARRAY_SIZE=32
+CONFIG_MCUMGR=y
+CONFIG_MCUMGR_TRANSPORT_DUMMY=y
+CONFIG_MCUMGR_TRANSPORT_DUMMY_RX_BUF_SIZE=384
+CONFIG_MCUMGR_GRP_OS=y
+CONFIG_MCUMGR_GRP_OS_ECHO=n
+CONFIG_MCUMGR_GRP_OS_MPSTAT=y
+CONFIG_ZTEST_STACK_SIZE=2048