module: mbedtls: add shell module

Add mbedTLS specific shell module, which allows (for now) to show heap
allocation statistics.

Signed-off-by: Marcin Niestroj <[email protected]>

Author: mniestroj

modules/mbedtls/CMakeLists.txt

@@ -23,6 +23,8 @@ if(CONFIG_MBEDTLS_BUILTIN)
     ${mbedtls_sources}
   )
 
+  zephyr_library_sources_ifdef(CONFIG_MBEDTLS_SHELL shell.c)
+
   zephyr_library_app_memory(k_mbedtls_partition)
 if(CONFIG_ARCH_POSIX AND CONFIG_ASAN AND NOT CONFIG_64BIT)
   # i386 assembly code used in MBEDTLS does not compile with size optimization

modules/mbedtls/Kconfig

@@ -151,6 +151,14 @@ config MBEDTLS_HEAP_SIZE
 	  be needed. For some dedicated and specific usage of mbedtls API, the
 	  1000 bytes might be ok.
 
+config MBEDTLS_SHELL
+	bool "mbed TLS shell"
+	depends on MBEDTLS
+	depends on SHELL
+	help
+	  Enable mbed TLS shell module, which allows to show debug information
+	  about mbed TLS library, such as heap usage.
+
 config APP_LINK_WITH_MBEDTLS
 	bool "Link 'app' with MBEDTLS"
 	default y

modules/mbedtls/shell.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2021 Marcin Niestroj
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <shell/shell.h>
+#include <mbedtls/memory_buffer_alloc.h>
+
+#if defined(MBEDTLS_MEMORY_DEBUG)
+static int cmd_mbedtls_heap_details(const struct shell *sh, size_t argc,
+				    char **argv)
+{
+	mbedtls_memory_buffer_alloc_status();
+
+	return 0;
+}
+
+static int cmd_mbedtls_heap_max_reset(const struct shell *sh, size_t argc,
+				  char **argv)
+{
+	mbedtls_memory_buffer_alloc_max_reset();
+
+	return 0;
+}
+
+static int cmd_mbedtls_heap(const struct shell *sh, size_t argc, char **argv)
+{
+	size_t max_used, max_blocks;
+	size_t cur_used, cur_blocks;
+
+	mbedtls_memory_buffer_alloc_max_get(&max_used, &max_blocks);
+	mbedtls_memory_buffer_alloc_cur_get(&cur_used, &cur_blocks);
+
+	shell_print(sh, "Maximum (peak): %zu bytes, %zu blocks",
+		    max_used, max_blocks);
+	shell_print(sh, "Current: %zu bytes, %zu blocks",
+		    cur_used, cur_blocks);
+
+	return 0;
+}
+
+SHELL_STATIC_SUBCMD_SET_CREATE(mbedtls_heap_cmds,
+	SHELL_CMD_ARG(details, NULL, "Print heap details",
+		      cmd_mbedtls_heap_details, 1, 0),
+	SHELL_CMD_ARG(max_reset, NULL, "Reset max heap statistics",
+		      cmd_mbedtls_heap_max_reset, 1, 0),
+	SHELL_SUBCMD_SET_END /* Array terminated. */
+);
+#endif
+
+SHELL_STATIC_SUBCMD_SET_CREATE(mbedtls_cmds,
+#if defined(MBEDTLS_MEMORY_DEBUG)
+	SHELL_CMD_ARG(heap, &mbedtls_heap_cmds, "Show heap status",
+		      cmd_mbedtls_heap, 1, 0),
+#endif
+	SHELL_SUBCMD_SET_END /* Array terminated. */
+);
+
+SHELL_CMD_REGISTER(mbedtls, &mbedtls_cmds, "mbed TLS commands", NULL);