From 4b6e3956d6a9dfb1dd2f1aa2fe386afc2fd4a7af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kuba=20Szczodrzy=C5=84ski?= <kuba@szczodrzynski.pl>
Date: Thu, 5 May 2022 21:25:19 +0200
Subject: [PATCH] [realtek-ambz] Implement SSL client, cleanup compilation

---
 README.md                                     |   2 +-
 arduino/realtek-ambz/cores/arduino/WVariant.h |  14 ++
 .../realtek-ambz/cores/arduino/rtl_sys.cpp    | 147 ++----------------
 .../libraries/WiFi/WiFiClientSecure.h         |   8 +
 builder/frameworks/realtek-ambz-arduino.py    |   4 +-
 builder/frameworks/realtek-ambz-sdk.py        | 127 +++++++--------
 .../realtek-ambz/memory-management.md         |  15 ++
 mkdocs.yml                                    |   2 +
 8 files changed, 106 insertions(+), 213 deletions(-)
 create mode 100644 arduino/realtek-ambz/libraries/WiFi/WiFiClientSecure.h
 create mode 100644 docs/platform/realtek-ambz/memory-management.md

diff --git a/README.md b/README.md
index 4c91be5..0701ac5 100644
--- a/README.md
+++ b/README.md
@@ -174,7 +174,7 @@ SPI                 | ❌
 Wire                | ❌
 **OTHER LIBRARIES** |
 Wi-Fi STA/AP/Mixed  | ✔️
-Wi-Fi Client (SSL)  | ✔️ (❌)
+Wi-Fi Client (SSL)  | ✔️ (✔️)
 Wi-Fi Server        | ✔️
 Wi-Fi Events        | ❌
 IPv6                | ❌
diff --git a/arduino/realtek-ambz/cores/arduino/WVariant.h b/arduino/realtek-ambz/cores/arduino/WVariant.h
index 0b634d4..0d627b8 100644
--- a/arduino/realtek-ambz/cores/arduino/WVariant.h
+++ b/arduino/realtek-ambz/cores/arduino/WVariant.h
@@ -12,6 +12,8 @@ extern "C" {
 #include <stdarg.h>
 #define boolean boolean_rtl
 #include "rtl_lib.h"
+#include "rand.h"
+#include "rt_lib_rom.h"
 #undef boolean
 
 /* moved from Arduino.h */
@@ -33,6 +35,18 @@ extern void wait_us(int us);
 
 extern void yield(void);
 
+extern void *pvPortMalloc(size_t xWantedSize);
+extern void *pvPortZalloc(size_t size);
+extern void *pvPortCalloc(size_t nmemb, size_t size);
+extern void *pvPortReAlloc(void *pv, size_t xWantedSize);
+extern void vPortFree(void *pv);
+
+#define malloc pvPortMalloc
+#define zalloc pvPortZalloc
+#define calloc pvPortCalloc
+#define realloc pvPortReAlloc
+#define free vPortFree
+
 #ifndef printf
 #define printf		rtl_printf
 #endif
diff --git a/arduino/realtek-ambz/cores/arduino/rtl_sys.cpp b/arduino/realtek-ambz/cores/arduino/rtl_sys.cpp
index 6382477..b2b2e2f 100644
--- a/arduino/realtek-ambz/cores/arduino/rtl_sys.cpp
+++ b/arduino/realtek-ambz/cores/arduino/rtl_sys.cpp
@@ -29,9 +29,6 @@ extern "C" {
 #include <diag.h>
 
 extern void *pvPortMalloc( size_t xWantedSize );
-extern void *os_zalloc( size_t xWantedSize );
-extern void vPortFree( void *pv );
-extern void *pvPortReAlloc( void *pv,  size_t xWantedSize );
 extern size_t xPortGetFreeHeapSize( void );
 extern size_t xPortGetMinimumEverFreeHeapSize( void );
 
@@ -45,7 +42,7 @@ extern int tcm_heap_freeSpace(void);
 __attribute__((noreturn)) void __panic_func(const char* file, int line, const char* func)
 {
 	DiagPrintf("\r\nPanic: %s, line: %d, %s\r\n");
-	while(1);	
+	while(1);
 }
 
 #ifdef __cplusplus
@@ -56,11 +53,11 @@ void hexdump(void * ptr, int cnt)
 {
 	char * p = (char *) ptr;
 	int c = cnt;
-	while(c > 64) { 
+	while(c > 64) {
 		DumpForOneBytes((void *)p, 64);
 		p += 64;
 		c -= 64;
-	} 
+	}
 	if(c != 0) DumpForOneBytes((void *)p, c);
 }
 
@@ -79,137 +76,13 @@ void sys_info(void) {
 				HalGetCpuClk(), xPortGetFreeHeapSize(), tcm_heap_freeSpace());
 }
 
-
-/* void * malloc(size_t size)
-{
-	void * ret;
-	if((ret = pvPortMalloc(size)) == NULL)
-		ret = tcm_heap_malloc(size);
-	return ret;
+void *pvPortZalloc(size_t size) {
+    void *pvReturn = pvPortMalloc(size);
+	if (pvReturn)
+		memset(pvReturn, 0, size);
+	return pvReturn;
 }
 
-void * zalloc(size_t size) 
-{
-	void * ret;
-	if((ret = pvPortMalloc(size)) == NULL)
-		ret = tcm_heap_calloc(size);
-	else memset(ret, 0, size);
-	return ret;
+void *pvPortCalloc(size_t nmemb, size_t size) {
+    return pvPortZalloc(nmemb * size);
 }
-
-void *calloc(size_t count, size_t size)
-{
-  return zalloc(count * size);
-} */
-
-void free(void *pv)
-{
-	vPortFree(pv);
-}
-
-void * realloc(void *pv, size_t size)
-{
-	return pvPortReAlloc(pv, size);
-}
-
-/* void *operator new(size_t size)
-{
-	void * ret;
-	if((ret = zalloc(size)) == NULL) {
-		DiagPrintf("\r\nMEM error!\r\n");
-		while(1);
-	}
-    return ret;
-}
-
-void *operator new[](size_t size)
-{
-	void * ret;
-	if((ret = zalloc(size)) == NULL) {
-		DiagPrintf("\r\nMEM error!\r\n");
-		while(1);
-	}
-    return ret;
-}
-
-void operator delete(void * ptr)
-{
-    free(ptr);
-}
-
-void operator delete[](void * ptr)
-{
-    free(ptr);
-} */
-
-/*
-extern "C" void __cxa_pure_virtual(void) __attribute__ ((__noreturn__));
-extern "C" void __cxa_deleted_virtual(void) __attribute__ ((__noreturn__));
-
-void __cxa_pure_virtual(void)
-{
-    panic();
-}
-
-void __cxa_deleted_virtual(void)
-{
-    panic();
-}
-
-typedef struct {
-    uint8_t guard;
-    uint8_t ps;
-} guard_t;
-
-extern "C" int __cxa_guard_acquire(__guard* pg)
-{
-    uint8_t ps = xt_rsil(15);
-    if (reinterpret_cast<guard_t*>(pg)->guard) {
-        xt_wsr_ps(ps);
-        return 0;
-    }
-    reinterpret_cast<guard_t*>(pg)->ps = ps;
-    return 1;
-}
-
-extern "C" void __cxa_guard_release(__guard* pg)
-{
-    reinterpret_cast<guard_t*>(pg)->guard = 1;
-    xt_wsr_ps(reinterpret_cast<guard_t*>(pg)->ps);
-}
-
-extern "C" void __cxa_guard_abort(__guard* pg)
-{
-    xt_wsr_ps(reinterpret_cast<guard_t*>(pg)->ps);
-}
-
-
-namespace std
-{
-void __throw_bad_function_call()
-{
-    panic();
-}
-
-void __throw_length_error(char const*)
-{
-    panic();
-}
-
-void __throw_bad_alloc()
-{
-    panic();
-}
-
-void __throw_logic_error(const char* str)
-{
-    panic();
-}
-
-void __throw_out_of_range(const char* str)
-{
-    panic();
-}
-}
-
-*/    
diff --git a/arduino/realtek-ambz/libraries/WiFi/WiFiClientSecure.h b/arduino/realtek-ambz/libraries/WiFi/WiFiClientSecure.h
new file mode 100644
index 0000000..a4b1456
--- /dev/null
+++ b/arduino/realtek-ambz/libraries/WiFi/WiFiClientSecure.h
@@ -0,0 +1,8 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-05-04. */
+
+#pragma once
+
+#include <WiFi.h>
+#include <ssl/MbedTLSClient.h>
+
+typedef MbedTLSClient WiFiClientSecure;
diff --git a/builder/frameworks/realtek-ambz-arduino.py b/builder/frameworks/realtek-ambz-arduino.py
index 316bfba..2afdb8a 100644
--- a/builder/frameworks/realtek-ambz-arduino.py
+++ b/builder/frameworks/realtek-ambz-arduino.py
@@ -6,6 +6,8 @@ from SCons.Script import DefaultEnvironment
 
 env = DefaultEnvironment()
 
+env.Replace(AMBZ_NO_POLARSSL=True)
+
 env.SConscript("realtek-ambz-sdk.py", exports="env")
 env.SConscript("../arduino-common.py", exports="env")
 
@@ -45,8 +47,8 @@ env.Append(
         # enable LwIPRxBuffer
         "LT_HAS_LWIP",
         ("LT_PRINTF_BROKEN", "1"),  # printf does not handle %.3f properly
-        ("zalloc", "os_zalloc"),
         "MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED",  # enable PSK in mbedTLS
+        # "MBEDTLS_DEBUG_C",
     ],
     LINKFLAGS=[
         "--specs=nosys.specs",
diff --git a/builder/frameworks/realtek-ambz-sdk.py b/builder/frameworks/realtek-ambz-sdk.py
index e27a0d7..a95bba3 100644
--- a/builder/frameworks/realtek-ambz-sdk.py
+++ b/builder/frameworks/realtek-ambz-sdk.py
@@ -35,7 +35,7 @@ env.Replace(
 )
 
 # Flags
-env.Replace(
+env.Append(
     CFLAGS=[
         "-std=gnu99",
         "-mcpu=cortex-m4",
@@ -101,7 +101,6 @@ env.AddLibrary(
     name="ambz_sdk",
     base_dir="$SDK_DIR",
     srcs=[
-        "+<component/common/application/uart_adapter/uart_adapter.c>",
         # NOTE: a fixup is used instead, to remove default main()
         # "+<component/soc/realtek/8711b/cmsis/device/app_start.c>",
         "+<component/soc/realtek/8711b/fwlib/ram_lib/startup.c>",
@@ -116,22 +115,6 @@ env.AddLibrary(
         "+<component/common/api/wifi/wifi_simple_config.c>",
         "+<component/common/api/wifi/wifi_util.c>",
         "+<component/common/api/lwip_netconf.c>",
-        "+<component/common/application/mqtt/MQTTClient/MQTTClient.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTConnectClient.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTConnectServer.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTDeserializePublish.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTFormat.c>",
-        "+<component/common/application/mqtt/MQTTClient/MQTTFreertos.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTPacket.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTSerializePublish.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTSubscribeClient.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTSubscribeServer.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTUnsubscribeClient.c>",
-        "+<component/common/application/mqtt/MQTTPacket/MQTTUnsubscribeServer.c>",
-        "+<component/common/api/network/src/ping_test.c>",
-        "+<component/common/utilities/ssl_client.c>",
-        "+<component/common/utilities/tcptest.c>",
-        "+<component/common/api/network/src/wlan_network.c>",
         "+<component/common/network/lwip/lwip_v1.4.1/src/api/api_lib.c>",
         "+<component/common/network/lwip/lwip_v1.4.1/src/api/api_msg.c>",
         "+<component/common/network/lwip/lwip_v1.4.1/src/api/err.c>",
@@ -168,52 +151,8 @@ env.AddLibrary(
         "+<component/common/network/lwip/lwip_v1.4.1/port/realtek/freertos/ethernetif.c>",
         "+<component/common/drivers/wlan/realtek/src/osdep/lwip_intf.c>",
         "+<component/common/network/lwip/lwip_v1.4.1/port/realtek/freertos/sys_arch.c>",
-        "+<component/common/network/websocket/wsclient_tls.c>",
         "+<component/common/network/dhcp/dhcps.c>",
         "+<component/common/network/sntp/sntp.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/aesni.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/blowfish.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/camellia.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ccm.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/certs.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/cipher.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/cipher_wrap.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/debug.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ecp_ram.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/entropy.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/entropy_poll.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/error.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/gcm.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/havege.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/md2.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/md4.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/memory_buffer_alloc.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/net.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/padlock.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/pbkdf2.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs11.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs12.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs5.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/pkparse.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/platform.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ripemd160.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_cache.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_ciphersuites.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_cli.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_srv.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_tls.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/threading.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/timing.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/version.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/version_features.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509_create.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509_crl.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509_crt.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509_csr.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509write_crt.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/x509write_csr.c>",
-        "+<component/common/network/ssl/polarssl-1.3.8/library/xtea.c>",
         "+<component/common/network/ssl/ssl_ram_map/ssl_ram_map.c>",
         "+<component/os/freertos/freertos_v8.1.2/Source/portable/MemMang/heap_5.c>",
         "+<component/os/freertos/freertos_v8.1.2/Source/portable/GCC/ARM_CM4F/port.c>",
@@ -257,11 +196,7 @@ env.AddLibrary(
         "+<component/soc/realtek/8711b/misc/rtl8710b_ota.c>",
         "+<component/soc/realtek/8711b/fwlib/ram_lib/rtl8710b_pinmapcfg.c>",
         "+<component/soc/realtek/8711b/fwlib/ram_lib/rtl8710b_sleepcfg.c>",
-        "+<component/common/network/httpc/httpc_tls.c>",
-        "+<component/common/network/httpd/httpd_tls.c>",
         "+<component/common/utilities/cJSON.c>",
-        "+<component/common/utilities/http_client.c>",
-        "+<component/common/utilities/uart_socket.c>",
         "+<component/common/utilities/xml.c>",
     ],
     includes=[
@@ -272,17 +207,12 @@ env.AddLibrary(
         "+<component/os/os_dep/include>",
         "+<component/common/api/network/include>",
         "+<component/common/api>",
-        "+<component/common/api/at_cmd>",
         "+<component/common/api/platform>",
         "+<component/common/api/wifi>",
         "+<component/common/api/wifi/rtw_wpa_supplicant/src>",
         "+<component/common/api/wifi/rtw_wowlan>",
         "+<component/common/api/wifi/rtw_wpa_supplicant/wpa_supplicant>",
         "+<component/common/application>",
-        "+<component/common/application/mqtt/MQTTClient>",
-        "+<component/common/application/mqtt/MQTTPacket>",
-        "+<component/common/example>",
-        "+<component/common/example/wlan_fast_connect>",
         "+<component/common/drivers/wlan/realtek/include>",
         "+<component/common/drivers/wlan/realtek/src/osdep>",
         "+<component/common/drivers/wlan/realtek/wlan_ram_map/rom>",
@@ -295,7 +225,6 @@ env.AddLibrary(
         "+<component/common/network/lwip/lwip_v1.4.1/port/realtek>",
         "+<component/common/network/ssl/polarssl-1.3.8/include>",
         "+<component/common/network/ssl/ssl_ram_map/rom>",
-        "+<component/common/test>",
         "+<component/common/utilities>",
         "+<component/soc/realtek/8711b/app/monitor/include>",
         "+<component/soc/realtek/8711b/cmsis>",
@@ -311,11 +240,61 @@ env.AddLibrary(
         "+<component/common/mbed/hal_ext>",
         "+<component/common/mbed/targets/cmsis>",
         "+<component/common/mbed/targets/hal/rtl8711b>",
-        "+<component/common/application/mqtt/MQTTClient>",
-        "+<component/common/network/websocket>",
     ],
 )
 
+# Sources - PolarSSL library
+if "AMBZ_NO_POLARSSL" not in env or not env["AMBZ_NO_POLARSSL"]:
+    env.AddLibrary(
+        name="ambz_polarssl",
+        base_dir="$SDK_DIR",
+        srcs=[
+            "+<component/common/network/ssl/polarssl-1.3.8/library/aesni.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/blowfish.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/camellia.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ccm.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/certs.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/cipher.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/cipher_wrap.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/debug.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ecp_ram.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/entropy.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/entropy_poll.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/error.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/gcm.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/havege.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/md2.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/md4.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/memory_buffer_alloc.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/net.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/padlock.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/pbkdf2.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs11.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs12.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/pkcs5.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/pkparse.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/platform.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ripemd160.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_cache.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_ciphersuites.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_cli.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_srv.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/ssl_tls.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/threading.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/timing.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/version.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/version_features.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509_create.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509_crl.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509_crt.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509_csr.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509write_crt.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/x509write_csr.c>",
+            "+<component/common/network/ssl/polarssl-1.3.8/library/xtea.c>",
+        ],
+    )
+
 # Sources - platform fixups
 env.AddLibrary(
     name="ambz_fixups",
diff --git a/docs/platform/realtek-ambz/memory-management.md b/docs/platform/realtek-ambz/memory-management.md
new file mode 100644
index 0000000..f65d243
--- /dev/null
+++ b/docs/platform/realtek-ambz/memory-management.md
@@ -0,0 +1,15 @@
+# Memory management
+
+Function      | Target                 | #define location                                  | Notes
+--------------|------------------------|---------------------------------------------------|------------------------------------------------------------------------------------------------
+__`malloc`__  | __`pvPortMalloc`__     | `component/common/api/platform/platform_stdlib.h` |
+`zalloc`      | `os_zalloc` (ROM)      |                                                   | This is **PROBABLY BROKEN**. ROM disassembly shows it only does memset on a fixed memory range.
+__`zalloc`__  | __`pvPortZalloc`__     | `arduino/realtek-ambz/cores/WVariant.h`           | Custom implementation in `rtl_sys.cpp`
+`calloc`      | `os_calloc`            | ?                                                 | This one is not in ROM. I didn't dig any deeper into it.
+`calloc`      | `calloc_freertos`      | `component/os/freertos/cmsis_os.h`                | Probably not used
+`calloc`      | `__rtl_calloc_r` (ROM) |                                                   | Not used, as I preferred to use FreeRTOS memory management.
+__`calloc`__  | __`pvPortCalloc`__     | `arduino/realtek-ambz/cores/WVariant.h`           | Custom implementation in `rtl_sys.cpp`
+__`realloc`__ | __`pvPortRealloc`__    | `arduino/realtek-ambz/cores/WVariant.h`           |
+__`free`__    | __`vPortFree`__        | `component/common/api/platform/platform_stdlib.h` |
+
+__Underlined__ item means that it is defined and used in code.
diff --git a/mkdocs.yml b/mkdocs.yml
index caf99cb..8780daa 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -19,5 +19,7 @@ nav:
       - "Realtek AmebaZ Series":
           - "Boards":
               - "WR3": "boards/wr3/README.md"
+          - "stdlib usage":
+              - "Memory management": "docs/platform/realtek-ambz/memory-management.md"
           - "Debugging": "docs/platform/realtek/debugging.md"
           - "Exception decoder": "docs/platform/realtek/exception-decoder.md"