From 1f88f28f8c8a2b75f5edd934855722c9bdf16cc4 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Wed, 8 Aug 2018 17:28:35 +0200
Subject: [PATCH 01/13] Automatic stack location selection (SYS or HEAP),
 remove unnecessary board generator option

---
 cores/esp8266/cont.h                          |  6 ++
 .../core_esp8266_app_entry_noextra4k.cpp      | 38 +++++++++
 cores/esp8266/core_esp8266_main.cpp           | 37 ++++----
 cores/esp8266/coredecls.h                     |  6 ++
 .../ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp    | 84 +++++++++++++++++++
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp  | 84 -------------------
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h    | 14 ++--
 .../src/WiFiClientSecureBearSSL.cpp           |  4 +-
 .../extra4kchecker/extra4kchecker.ino         | 42 ++++++++++
 platform.txt                                  |  5 +-
 tools/boards.txt.py                           |  8 +-
 tools/sdk/include/user_interface.h            | 14 ----
 12 files changed, 206 insertions(+), 136 deletions(-)
 create mode 100644 cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
 create mode 100644 libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
 create mode 100644 libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino

diff --git a/cores/esp8266/cont.h b/cores/esp8266/cont.h
index 46daad1007..1fe2cb634b 100644
--- a/cores/esp8266/cont.h
+++ b/cores/esp8266/cont.h
@@ -45,6 +45,12 @@ typedef struct cont_ {
         unsigned* struct_start;
 } cont_t;
 
+/* Not static, used in core_esp8266_postmortem.c.
+ * Placed into noinit section because we assign value to this variable
+ * before .bss is zero-filled, and need to preserve the value.
+ */
+extern cont_t* g_pcont __attribute__((section(".noinit")));
+
 // Initialize the cont_t structure before calling cont_run
 void cont_init(cont_t*);
 
diff --git a/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
new file mode 100644
index 0000000000..5f4210762b
--- /dev/null
+++ b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
@@ -0,0 +1,38 @@
+/*
+ *  This is the original app_entry() not providing extra 4K heap, but allowing
+ *  the use of WPS.
+ *
+ *  see comments in core_esp8266_main.cpp's app_entry()
+ *
+ */
+
+#include <c_types.h>
+#include "cont.h"
+#include "coredecls.h"
+
+// calls to this function must *always* be inlined
+void disable_extra4k_at_link_time (void)
+{
+    /*
+     * does nothing
+     * allows overriding the core_esp8266_main.cpp's app_entry()
+     * by this one below, at link time
+     *
+     */
+}
+
+/* the following code is linked only if a call to the above function is made somewhere */
+
+extern "C" void call_user_start();
+
+/* this is the default NONOS-SDK user's heap location */
+static cont_t g_cont __attribute__ ((aligned (16)));
+
+extern "C" void ICACHE_RAM_ATTR app_entry_redefinable(void)
+{
+    /* this is the default NONOS-SDK user's heap location */
+    g_pcont = &g_cont;
+
+    /* Call the entry point of the SDK code. */
+    call_user_start();
+}
diff --git a/cores/esp8266/core_esp8266_main.cpp b/cores/esp8266/core_esp8266_main.cpp
index ba878b5679..f64d60079c 100644
--- a/cores/esp8266/core_esp8266_main.cpp
+++ b/cores/esp8266/core_esp8266_main.cpp
@@ -175,10 +175,15 @@ void init_done() {
 
    WPS beeing flawed by its poor security, or not beeing used by lots of
    users, it has been decided that we are still going to use that memory for
-   user's stack and disable the use of WPS, with an option to revert that
-   back at the user's discretion.  This selection can be done with the
-   global define NO_EXTRA_4K_HEAP.  An option has been added to the board
-   generator script.
+   user's stack and disable the use of WPS.
+
+   app_entry() jumps to app_entry_custom() defined as "weakref" calling
+   itself a weak customizable function, allowing to use another one when
+   this is required (see core_esp8266_app_entry_noextra4k.cpp, used by WPS).
+
+   (note: setting app_entry() itself as "weak" is not sufficient and always
+    ends up with the other "noextra4k" one linked, maybe because it has a
+    default value in linker scripts).
 
    References:
    https://github.com/esp8266/Arduino/pull/4553
@@ -188,31 +193,25 @@ void init_done() {
 
 */
 
-#ifdef NO_EXTRA_4K_HEAP
-/* this is the default NONOS-SDK user's heap location */
-cont_t g_cont __attribute__ ((aligned (16)));
-#endif
-
-extern "C" void ICACHE_RAM_ATTR app_entry(void)
+extern "C" void ICACHE_RAM_ATTR app_entry_redefinable(void) __attribute__((weak));
+extern "C" void ICACHE_RAM_ATTR app_entry_redefinable(void)
 {
-#ifdef NO_EXTRA_4K_HEAP
-
-    /* this is the default NONOS-SDK user's heap location */
-    g_pcont = &g_cont;
-
-#else
-
     /* Allocate continuation context on this SYS stack,
        and save pointer to it. */
     cont_t s_cont __attribute__((aligned(16)));
     g_pcont = &s_cont;
 
-#endif
-
     /* Call the entry point of the SDK code. */
     call_user_start();
 }
 
+static void ICACHE_RAM_ATTR app_entry_custom (void) __attribute__((weakref("app_entry_redefinable")));
+
+extern "C" void ICACHE_RAM_ATTR app_entry (void)
+{
+    return app_entry_custom();
+}
+
 extern "C" void user_init(void) {
     struct rst_info *rtc_info_ptr = system_get_rst_info();
     memcpy((void *) &resetInfo, (void *) rtc_info_ptr, sizeof(resetInfo));
diff --git a/cores/esp8266/coredecls.h b/cores/esp8266/coredecls.h
index 9e06419ca4..5212c84211 100644
--- a/cores/esp8266/coredecls.h
+++ b/cores/esp8266/coredecls.h
@@ -8,11 +8,17 @@ extern "C" {
 
 // TODO: put declarations here, get rid of -Wno-implicit-function-declaration
 
+
 extern bool timeshift64_is_set;
 
+void esp_yield();
+void esp_schedule();
 void tune_timeshift64 (uint64_t now_us);
 void settimeofday_cb (void (*cb)(void));
 
+// calls to this function must *always* be inlined
+void disable_extra4k_at_link_time (void) __attribute__((noinline));
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
new file mode 100644
index 0000000000..5b99b187b0
--- /dev/null
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
@@ -0,0 +1,84 @@
+
+#include "ESP8266WiFi.h"
+#include "ESP8266WiFiGeneric.h"
+#include "ESP8266WiFiSTA.h"
+
+void wifi_wps_status_cb(wps_cb_status status);
+
+/**
+ * WPS config
+ * so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
+ * @return ok
+ */
+bool beginWPSConfig(void) {
+
+    if(!WiFi.enableSTA(true)) {
+        // enable STA failed
+        return false;
+    }
+
+    WiFi.disconnect();
+
+    DEBUGV("wps begin\n");
+
+    if(!wifi_wps_disable()) {
+        DEBUGV("wps disable failed\n");
+        return false;
+    }
+
+    // so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
+    if(!wifi_wps_enable(WPS_TYPE_PBC)) {
+        DEBUGV("wps enable failed\n");
+        return false;
+    }
+
+    if(!wifi_set_wps_cb((wps_st_cb_t) &wifi_wps_status_cb)) {
+        DEBUGV("wps cb failed\n");
+        return false;
+    }
+
+    if(!wifi_wps_start()) {
+        DEBUGV("wps start failed\n");
+        return false;
+    }
+
+    esp_yield();
+    // will return here when wifi_wps_status_cb fires
+
+    return true;
+}
+
+/**
+ * WPS callback
+ * @param status wps_cb_status
+ */
+void wifi_wps_status_cb(wps_cb_status status) {
+    DEBUGV("wps cb status: %d\r\n", status);
+    switch(status) {
+        case WPS_CB_ST_SUCCESS:
+            if(!wifi_wps_disable()) {
+                DEBUGV("wps disable failed\n");
+            }
+            wifi_station_connect();
+            break;
+        case WPS_CB_ST_FAILED:
+            DEBUGV("wps FAILED\n");
+            break;
+        case WPS_CB_ST_TIMEOUT:
+            DEBUGV("wps TIMEOUT\n");
+            break;
+        case WPS_CB_ST_WEP:
+            DEBUGV("wps WEP\n");
+            break;
+        case WPS_CB_ST_UNK:
+            DEBUGV("wps UNKNOWN\n");
+            if(!wifi_wps_disable()) {
+                DEBUGV("wps disable failed\n");
+            }
+            break;
+    }
+    // TODO user function to get status
+
+    esp_schedule(); // resume the beginWPSConfig function
+}
+
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp
index 730b52886a..5f2c2c3b05 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp
@@ -571,90 +571,6 @@ int32_t ESP8266WiFiSTAClass::RSSI(void) {
 // -------------------------------------------------- STA remote configure -----------------------------------------------
 // -----------------------------------------------------------------------------------------------------------------------
 
-#ifdef NO_EXTRA_4K_HEAP
-/* NO_EXTRA_4K_HEAP's description in cores/esp8266/core_esp8266_main.cpp */
-
-void wifi_wps_status_cb(wps_cb_status status);
-
-/**
- * WPS config
- * so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
- * @return ok
- */
-bool ESP8266WiFiSTAClass::beginWPSConfig(void) {
-
-    if(!WiFi.enableSTA(true)) {
-        // enable STA failed
-        return false;
-    }
-
-    disconnect();
-
-    DEBUGV("wps begin\n");
-
-    if(!wifi_wps_disable()) {
-        DEBUGV("wps disable failed\n");
-        return false;
-    }
-
-    // so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
-    if(!wifi_wps_enable(WPS_TYPE_PBC)) {
-        DEBUGV("wps enable failed\n");
-        return false;
-    }
-
-    if(!wifi_set_wps_cb((wps_st_cb_t) &wifi_wps_status_cb)) {
-        DEBUGV("wps cb failed\n");
-        return false;
-    }
-
-    if(!wifi_wps_start()) {
-        DEBUGV("wps start failed\n");
-        return false;
-    }
-
-    esp_yield();
-    // will return here when wifi_wps_status_cb fires
-
-    return true;
-}
-
-/**
- * WPS callback
- * @param status wps_cb_status
- */
-void wifi_wps_status_cb(wps_cb_status status) {
-    DEBUGV("wps cb status: %d\r\n", status);
-    switch(status) {
-        case WPS_CB_ST_SUCCESS:
-            if(!wifi_wps_disable()) {
-                DEBUGV("wps disable failed\n");
-            }
-            wifi_station_connect();
-            break;
-        case WPS_CB_ST_FAILED:
-            DEBUGV("wps FAILED\n");
-            break;
-        case WPS_CB_ST_TIMEOUT:
-            DEBUGV("wps TIMEOUT\n");
-            break;
-        case WPS_CB_ST_WEP:
-            DEBUGV("wps WEP\n");
-            break;
-        case WPS_CB_ST_UNK:
-            DEBUGV("wps UNKNOWN\n");
-            if(!wifi_wps_disable()) {
-                DEBUGV("wps disable failed\n");
-            }
-            break;
-    }
-    // TODO user function to get status
-
-    esp_schedule(); // resume the beginWPSConfig function
-}
-
-#endif // NO_EXTRA_4K_HEAP
-
 bool ESP8266WiFiSTAClass::_smartConfigStarted = false;
 bool ESP8266WiFiSTAClass::_smartConfigDone = false;
 
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index f94ba0a4d3..9ce10297c2 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -27,7 +27,9 @@
 #include "ESP8266WiFiType.h"
 #include "ESP8266WiFiGeneric.h"
 #include "user_interface.h"
+#include "coredecls.h" // disable_extra4k_at_link_time()
 
+extern bool beginWPSConfig(void);
 
 class ESP8266WiFiSTAClass {
         // ----------------------------------------------------------------------------------------------
@@ -93,14 +95,12 @@ class ESP8266WiFiSTAClass {
 
     public:
 
-#ifdef NO_EXTRA_4K_HEAP
-        bool beginWPSConfig(void);
-#else
-        inline bool beginWPSConfig(void) __attribute__((always_inline)) {
-            return WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool();
+        inline bool beginWPSConfig(void) __attribute__((always_inline))
+        {
+            disable_extra4k_at_link_time(); // this call must always be inlined
+            return ::beginWPSConfig();
         }
-#endif
-
+        
         bool beginSmartConfig();
         bool stopSmartConfig();
         bool smartConfigDone();
diff --git a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
index 890d86c8e3..0e28295520 100644
--- a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
+++ b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
@@ -1260,13 +1260,13 @@ bool WiFiClientSecure::loadPrivateKey(Stream& stream, size_t size) {
 
 extern "C" {
 #include <cont.h>
-  extern cont_t g_cont;
+  extern cont_t *g_pcont;
   extern size_t br_esp8266_stack_proxy_usage();
 
   void _BearSSLCheckStack(const char *fcn, const char *file, int line) {
     static int cnt = 0;
     register uint32_t *sp asm("a1");
-    int freestack = 4 * (sp - g_cont.stack);
+    int freestack = 4 * (sp - g_pcont->stack);
     int freeheap = ESP.getFreeHeap();
     static int laststack, lastheap, laststack2;
     if ((laststack != freestack) || (lastheap != freeheap) || (laststack2 != (int)br_esp8266_stack_proxy_usage())) {
diff --git a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
new file mode 100644
index 0000000000..d679de10bd
--- /dev/null
+++ b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
@@ -0,0 +1,42 @@
+
+/*
+   This is a debugging / validation test only
+
+   It demonstrates the effect of calling
+       disable_extra4k_at_link_time()
+
+   Currently only WPS is using that call
+
+   released to public domain
+*/
+
+#include <ESP8266WiFi.h>
+#include <cont.h>
+
+#define USE_WPS 0 // try me with 0 or 1
+
+extern cont_t* g_pcont;
+
+void setup() {
+
+  Serial.begin(115200);
+  Serial.setDebugOutput(true);
+  WiFi.mode(WIFI_STA);
+  bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
+  Serial.printf("\nUsing sys stack: %s\ncont: %p (USER:0x3ffe SYS:0x3fff)\n"
+                "check https://github.com/esp8266/esp8266-wiki/wiki/Memory-Map)\n",
+                sysstack ? "YES" : "NO",
+                g_pcont);
+
+  Serial.printf("FreeHeap: %d (~52112 without WPS, ~46832 with)\n", ESP.getFreeHeap());
+
+#if USE_WPS
+  Serial.printf("starting WPS...\n");
+  Serial.printf("wps: %d\n", WiFi.beginWPSConfig());
+#else
+  Serial.printf("done\n");
+#endif
+}
+
+void loop() {
+}
diff --git a/platform.txt b/platform.txt
index 69b2d6536c..429cea6ec2 100644
--- a/platform.txt
+++ b/platform.txt
@@ -25,7 +25,6 @@ build.vtable_flags=-DVTABLES_IN_FLASH
 
 build.float=-u _printf_float -u _scanf_float
 build.led=
-build.noextra4kheap=
 
 compiler.path={runtime.tools.xtensa-lx106-elf-gcc.path}/bin/
 compiler.sdk.path={runtime.platform.path}/tools/sdk
@@ -33,7 +32,7 @@ compiler.libc.path={runtime.platform.path}/tools/sdk/libc/xtensa-lx106-elf
 compiler.cpreprocessor.flags=-D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ "-I{compiler.sdk.path}/include" "-I{compiler.sdk.path}/{build.lwip_include}" "-I{compiler.libc.path}/include" "-I{build.path}/core"
 
 compiler.c.cmd=xtensa-lx106-elf-gcc
-compiler.c.flags=-c {compiler.warning_flags} {build.noextra4kheap} -Os -g -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -std=gnu99 -ffunction-sections -fdata-sections
+compiler.c.flags=-c {compiler.warning_flags} -Os -g -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -std=gnu99 -ffunction-sections -fdata-sections
 
 compiler.S.cmd=xtensa-lx106-elf-gcc
 compiler.S.flags=-c -g -x assembler-with-cpp -MMD -mlongcalls
@@ -44,7 +43,7 @@ compiler.c.elf.cmd=xtensa-lx106-elf-gcc
 compiler.c.elf.libs=-lhal -lphy -lpp -lnet80211 {build.lwip_lib} -lwpa -lcrypto -lmain -lwps -lbearssl -laxtls -lespnow -lsmartconfig -lairkiss -lwpa2 -lstdc++ -lm -lc -lgcc
 
 compiler.cpp.cmd=xtensa-lx106-elf-g++
-compiler.cpp.flags=-c {compiler.warning_flags} {build.noextra4kheap} -Os -g -mlongcalls -mtext-section-literals -fno-exceptions -fno-rtti -falign-functions=4 -std=c++11 -MMD -ffunction-sections -fdata-sections
+compiler.cpp.flags=-c {compiler.warning_flags} -Os -g -mlongcalls -mtext-section-literals -fno-exceptions -fno-rtti -falign-functions=4 -std=c++11 -MMD -ffunction-sections -fdata-sections
 
 compiler.as.cmd=xtensa-lx106-elf-as
 
diff --git a/tools/boards.txt.py b/tools/boards.txt.py
index fe60838a35..221e6bfdc7 100755
--- a/tools/boards.txt.py
+++ b/tools/boards.txt.py
@@ -1275,9 +1275,6 @@ def all_boards ():
         if nofloat:
             print(id + '.build.float=')
 
-        if noextra4kheap:
-            print(id + '.build.noextra4kheap=-DNO_EXTRA_4K_HEAP')
-
         print('')
 
     if boardsgen:
@@ -1372,8 +1369,6 @@ def usage (name,ret):
     print(" --speed s       - change default serial speed")
     print(" --customspeed s - new serial speed for all boards")
     print(" --nofloat       - disable float support in printf/scanf")
-    print(" --noextra4kheap - disable extra 4k heap (will enable WPS)")
-    print(" --allowWPS      - synonym for --noextra4kheap")
     print("")
     print(" mandatory option (at least one):")
     print("")
@@ -1417,7 +1412,6 @@ def usage (name,ret):
 led_default = 2
 led_max = 16
 nofloat = False
-noextra4kheap = False
 ldgen = False
 ldshow = False
 boardsgen = False
@@ -1478,7 +1472,7 @@ def usage (name,ret):
         nofloat=True
 
     elif o in ("--noextra4kheap", "--allowWPS"):
-        noextra4kheap=True
+        print('option ' + o + ' is now useless')
 
     elif o in ("--ldshow"):
         ldshow = True
diff --git a/tools/sdk/include/user_interface.h b/tools/sdk/include/user_interface.h
index d2a4152ef7..a7733a9548 100644
--- a/tools/sdk/include/user_interface.h
+++ b/tools/sdk/include/user_interface.h
@@ -577,25 +577,11 @@ enum wps_cb_status {
 
 typedef void (*wps_st_cb_t)(int status);
 
-#ifdef NO_EXTRA_4K_HEAP
-/* check cores/esp8266/core_esp8266_main.cpp for comments about this */
-
 bool wifi_wps_enable(WPS_TYPE_t wps_type);
 bool wifi_wps_disable(void);
 bool wifi_wps_start(void);
 bool wifi_set_wps_cb(wps_st_cb_t cb);
 
-#else
-
-bool WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool ();
-#define wifi_wps_enable(...) WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool()
-#define wifi_wps_disable() WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool()
-#define wifi_wps_start() WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool()
-#define wifi_set_wps_cb(...) WPS_is_unavailable_in_this_configuration__Please_check_FAQ_or_board_generator_tool()
-
-#endif
-
-
 typedef void (*freedom_outside_cb_t)(uint8 status);
 int wifi_register_send_pkt_freedom_cb(freedom_outside_cb_t cb);
 void wifi_unregister_send_pkt_freedom_cb(void);

From 60d3b4eff9723dc96e229c9ea18524aa7dd9d7fb Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Wed, 8 Aug 2018 17:47:08 +0200
Subject: [PATCH 02/13] documentation updates

---
 cores/esp8266/coredecls.h                  |  1 -
 doc/faq/a05-board-generator.rst            |  2 --
 doc/faq/readme.rst                         | 16 ++++++++++------
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h |  2 +-
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/cores/esp8266/coredecls.h b/cores/esp8266/coredecls.h
index 5212c84211..9665fdc2fb 100644
--- a/cores/esp8266/coredecls.h
+++ b/cores/esp8266/coredecls.h
@@ -8,7 +8,6 @@ extern "C" {
 
 // TODO: put declarations here, get rid of -Wno-implicit-function-declaration
 
-
 extern bool timeshift64_is_set;
 
 void esp_yield();
diff --git a/doc/faq/a05-board-generator.rst b/doc/faq/a05-board-generator.rst
index 4aea17df8c..d68b9b1d1f 100644
--- a/doc/faq/a05-board-generator.rst
+++ b/doc/faq/a05-board-generator.rst
@@ -48,8 +48,6 @@ As of today you can:
 
 * increase available flash space by disabling floats in ``*printf`` functions
 
-* enable WPS which is now disabled by default (at the cost of a smaller heap by ~4KB)
-
 * change led pin ``LED_BUILTIN`` for the two generic boards
 
 * change the default lwIP version (1.4 or 2)
diff --git a/doc/faq/readme.rst b/doc/faq/readme.rst
index 2ed3743a50..b4ff2659e6 100644
--- a/doc/faq/readme.rst
+++ b/doc/faq/readme.rst
@@ -46,22 +46,26 @@ How can I get some extra KBs in flash ?
 * Using ``*printf()`` with floats is enabled by default.  Some KBs of flash can
   be saved by using the option ``--nofloat`` with the boards generator:
 
-  ``./tools/boards.txt.py --nofloat --allgen``
+  ``./tools/boards.txt.py --nofloat --boardsgen``
 
 * Use the debug level option ``NoAssert-NDEBUG`` (in the Tools menu)
 
 `Read more <a05-board-generator.rst>`__.
 
-Why can't I use WPS ?
-~~~~~~~~~~~~~~~~~~~~~
+About WPS
+~~~~~~~~~
 
-WPS is disabled by default, this offers an extra 4KB in ram/heap.  To enable
-WPS (and lose 4KB of useable ram), use this boards generator option:
+In release 2.4.2 only, WPS is disabled by default.  To enable WPS, use this
+boards generator option:
 
-``./tools/boards.txt.py --allowWPS --allgen``
+``./tools/boards.txt.py --allowWPS --boardsgen``
 
 `Read more <a05-board-generator.rst>`__.
 
+From release 2.4.2 and ahead, using WPS will reduce available heap space to
+user by around 4.5KB.  In other words, from release 2.4.2 without using WPS,
+an extra ~4.5KB is available in user's heap space.
+
 This Arduino library doesn't work on ESP. How do I make it work?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index 9ce10297c2..22bf10c519 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -100,7 +100,7 @@ class ESP8266WiFiSTAClass {
             disable_extra4k_at_link_time(); // this call must always be inlined
             return ::beginWPSConfig();
         }
-        
+
         bool beginSmartConfig();
         bool stopSmartConfig();
         bool smartConfigDone();

From 05b2aeeb203c0e0f8be05a992557f866d4f8dfb1 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 14:39:06 +0200
Subject: [PATCH 03/13] dot_a_linkage=true

---
 libraries/ArduinoOTA/library.properties              | 1 +
 libraries/DNSServer/library.properties               | 1 +
 libraries/EEPROM/library.properties                  | 1 +
 libraries/ESP8266AVRISP/library.properties           | 1 +
 libraries/ESP8266HTTPClient/library.properties       | 1 +
 libraries/ESP8266HTTPUpdateServer/library.properties | 1 +
 libraries/ESP8266NetBIOS/library.properties          | 1 +
 libraries/ESP8266WebServer/library.properties        | 1 +
 libraries/ESP8266WiFi/library.properties             | 1 +
 libraries/ESP8266WiFiMesh/library.properties         | 1 +
 libraries/ESP8266httpUpdate/library.properties       | 1 +
 libraries/Ethernet/library.properties                | 1 +
 libraries/GDBStub/library.properties                 | 1 +
 libraries/Hash/library.properties                    | 1 +
 libraries/SD/library.properties                      | 1 +
 libraries/SPI/library.properties                     | 1 +
 libraries/SPISlave/library.properties                | 1 +
 libraries/Servo/library.properties                   | 1 +
 libraries/Ticker/library.properties                  | 1 +
 libraries/Wire/library.properties                    | 1 +
 libraries/esp8266/library.properties                 | 1 +
 platform.txt                                         | 6 ++++--
 tests/device/libraries/BSTest/library.properties     | 1 +
 23 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/libraries/ArduinoOTA/library.properties b/libraries/ArduinoOTA/library.properties
index 1c72335c81..18bf6a52fd 100644
--- a/libraries/ArduinoOTA/library.properties
+++ b/libraries/ArduinoOTA/library.properties
@@ -7,3 +7,4 @@ paragraph=With this library you can enable your sketch to be upgraded over netwo
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/DNSServer/library.properties b/libraries/DNSServer/library.properties
index 71f0ae5440..fc9f0f7fa1 100644
--- a/libraries/DNSServer/library.properties
+++ b/libraries/DNSServer/library.properties
@@ -7,3 +7,4 @@ paragraph=This library implements a simple DNS server.
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/EEPROM/library.properties b/libraries/EEPROM/library.properties
index 3a638c4a32..de05c4f3de 100644
--- a/libraries/EEPROM/library.properties
+++ b/libraries/EEPROM/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Data Storage
 url=http://arduino.cc/en/Reference/EEPROM
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266AVRISP/library.properties b/libraries/ESP8266AVRISP/library.properties
index 70fa3cf8e5..59f581a546 100644
--- a/libraries/ESP8266AVRISP/library.properties
+++ b/libraries/ESP8266AVRISP/library.properties
@@ -7,3 +7,4 @@ paragraph=This library allows programming 8-bit AVR ICSP targets via TCP over Wi
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266HTTPClient/library.properties b/libraries/ESP8266HTTPClient/library.properties
index a63eb5717b..af2cf8ddf8 100644
--- a/libraries/ESP8266HTTPClient/library.properties
+++ b/libraries/ESP8266HTTPClient/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Communication
 url=https://github.com/esp8266/Arduino/blob/master/libraries/ESP8266HTTPClient
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266HTTPUpdateServer/library.properties b/libraries/ESP8266HTTPUpdateServer/library.properties
index 5fd9988715..23ced5a862 100644
--- a/libraries/ESP8266HTTPUpdateServer/library.properties
+++ b/libraries/ESP8266HTTPUpdateServer/library.properties
@@ -7,3 +7,4 @@ paragraph=The library accepts HTTP post requests to the /update url, and updates
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266NetBIOS/library.properties b/libraries/ESP8266NetBIOS/library.properties
index 510f9937c9..b72e43dcf8 100644
--- a/libraries/ESP8266NetBIOS/library.properties
+++ b/libraries/ESP8266NetBIOS/library.properties
@@ -7,3 +7,4 @@ paragraph=With this library you can connect to your ESP from Windows using a sho
 category=Communication
 url=http://www.xpablo.cz/?p=751#more-751
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266WebServer/library.properties b/libraries/ESP8266WebServer/library.properties
index 4dd12d3ba6..73e33ab14f 100644
--- a/libraries/ESP8266WebServer/library.properties
+++ b/libraries/ESP8266WebServer/library.properties
@@ -7,3 +7,4 @@ paragraph=The library supports HTTP GET and POST requests, provides argument par
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266WiFi/library.properties b/libraries/ESP8266WiFi/library.properties
index 3db731e8ed..35aae4ccf8 100644
--- a/libraries/ESP8266WiFi/library.properties
+++ b/libraries/ESP8266WiFi/library.properties
@@ -7,3 +7,4 @@ paragraph=With this library you can instantiate Servers, Clients and send/receiv
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266WiFiMesh/library.properties b/libraries/ESP8266WiFiMesh/library.properties
index 5dc4dec11a..70dff32590 100644
--- a/libraries/ESP8266WiFiMesh/library.properties
+++ b/libraries/ESP8266WiFiMesh/library.properties
@@ -7,3 +7,4 @@ paragraph=The library sets up a Mesh Node which acts as a router, creating a Mes
 category=Communication
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/ESP8266httpUpdate/library.properties b/libraries/ESP8266httpUpdate/library.properties
index 94a8499b89..f94d2102fe 100644
--- a/libraries/ESP8266httpUpdate/library.properties
+++ b/libraries/ESP8266httpUpdate/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Data Processing
 url=https://github.com/Links2004/Arduino/tree/esp8266/hardware/esp8266com/esp8266/libraries/ESP8266httpUpdate
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/Ethernet/library.properties b/libraries/Ethernet/library.properties
index 17fcae1003..00320f2acc 100644
--- a/libraries/Ethernet/library.properties
+++ b/libraries/Ethernet/library.properties
@@ -7,3 +7,4 @@ paragraph=With this library you can use the Arduino Ethernet (shield or board) t
 category=Communication
 url=http://www.arduino.cc/en/Reference/Ethernet
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/GDBStub/library.properties b/libraries/GDBStub/library.properties
index 0ede834fdd..28a69deef6 100644
--- a/libraries/GDBStub/library.properties
+++ b/libraries/GDBStub/library.properties
@@ -7,3 +7,4 @@ paragraph=GDB server stub helps debug crashes when JTAG isn't an option.
 category=Uncategorized
 url=https://github.com/espressif/esp-gdbstub
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/Hash/library.properties b/libraries/Hash/library.properties
index 81c8bba77d..82ce85b1d9 100644
--- a/libraries/Hash/library.properties
+++ b/libraries/Hash/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Data Processing
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/SD/library.properties b/libraries/SD/library.properties
index 40891c831a..42a1602564 100644
--- a/libraries/SD/library.properties
+++ b/libraries/SD/library.properties
@@ -7,3 +7,4 @@ paragraph=Once an SD memory card is connected to the SPI interfare of the Arduin
 category=Data Storage
 url=http://www.arduino.cc/en/Reference/SD
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/SPI/library.properties b/libraries/SPI/library.properties
index 46f7d47f33..950045187f 100644
--- a/libraries/SPI/library.properties
+++ b/libraries/SPI/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Signal Input/Output
 url=http://arduino.cc/en/Reference/SPI
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/SPISlave/library.properties b/libraries/SPISlave/library.properties
index 50d81f3fb8..bca1281dd2 100644
--- a/libraries/SPISlave/library.properties
+++ b/libraries/SPISlave/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Signal Input/Output
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/Servo/library.properties b/libraries/Servo/library.properties
index d19ef5886d..df32b66167 100644
--- a/libraries/Servo/library.properties
+++ b/libraries/Servo/library.properties
@@ -7,3 +7,4 @@ paragraph=This library can control a great number of servos.<br />It makes caref
 category=Device Control
 url=http://arduino.cc/en/Reference/Servo
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/Ticker/library.properties b/libraries/Ticker/library.properties
index 9261ad22dd..a759351e4c 100644
--- a/libraries/Ticker/library.properties
+++ b/libraries/Ticker/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Timing
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/Wire/library.properties b/libraries/Wire/library.properties
index 19eb0f43a7..c8f4ae1d85 100644
--- a/libraries/Wire/library.properties
+++ b/libraries/Wire/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Signal Input/Output
 url=http://arduino.cc/en/Reference/Wire
 architectures=esp8266
+dot_a_linkage=true
diff --git a/libraries/esp8266/library.properties b/libraries/esp8266/library.properties
index 15b1a31486..6e1cc8aded 100644
--- a/libraries/esp8266/library.properties
+++ b/libraries/esp8266/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Other
 url=
 architectures=esp8266
+dot_a_linkage=true
diff --git a/platform.txt b/platform.txt
index 429cea6ec2..83e1d72bf2 100644
--- a/platform.txt
+++ b/platform.txt
@@ -91,10 +91,12 @@ recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpreprocessor
 recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.S.flags} -DF_CPU={build.f_cpu} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {build.led} {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Create archives
-recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/arduino.ar" "{object_file}"
+#recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/arduino.ar" "{object_file}"
+recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}"
 
 ## Combine gc-sections, archives, and objects
-recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{build.path}/arduino.ar" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
+#recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{build.path}/arduino.ar" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
+recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" "-L{build.path}" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
 
 ## Create eeprom
 recipe.objcopy.eep.pattern=
diff --git a/tests/device/libraries/BSTest/library.properties b/tests/device/libraries/BSTest/library.properties
index cd65913497..f2399ca939 100644
--- a/tests/device/libraries/BSTest/library.properties
+++ b/tests/device/libraries/BSTest/library.properties
@@ -7,3 +7,4 @@ paragraph=
 category=Uncategorized
 url=
 architectures=esp8266
+dot_a_linkage=true

From 6ed54ee5ad55f9dfbcbc0b667a84f40c68946e33 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 14:39:57 +0200
Subject: [PATCH 04/13] WIP: fixes from @igrr's review

---
 cores/esp8266/cont.h                          |  8 ++++
 .../core_esp8266_app_entry_noextra4k.cpp      |  3 +-
 cores/esp8266/core_esp8266_postmortem.c       |  2 -
 cores/esp8266/coredecls.h                     |  2 +
 .../ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp    | 38 +++++++++++++++----
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h    | 13 +++----
 .../src/WiFiClientSecureBearSSL.cpp           |  2 -
 .../extra4kchecker/extra4kchecker.ino         |  2 -
 8 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/cores/esp8266/cont.h b/cores/esp8266/cont.h
index 1fe2cb634b..13b51babe6 100644
--- a/cores/esp8266/cont.h
+++ b/cores/esp8266/cont.h
@@ -27,6 +27,10 @@
 #define CONT_STACKSIZE 4096
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef struct cont_ {
         void (*pc_ret)(void);
         unsigned* sp_ret;
@@ -74,4 +78,8 @@ int cont_get_free_stack(cont_t* cont);
 // continuation stack
 bool cont_can_yield(cont_t* cont);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* CONT_H_ */
diff --git a/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
index 5f4210762b..1aa380459d 100644
--- a/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
+++ b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
@@ -10,7 +10,7 @@
 #include "cont.h"
 #include "coredecls.h"
 
-// calls to this function must *always* be inlined
+// callers to this function must *always* be inlined
 void disable_extra4k_at_link_time (void)
 {
     /*
@@ -30,7 +30,6 @@ static cont_t g_cont __attribute__ ((aligned (16)));
 
 extern "C" void ICACHE_RAM_ATTR app_entry_redefinable(void)
 {
-    /* this is the default NONOS-SDK user's heap location */
     g_pcont = &g_cont;
 
     /* Call the entry point of the SDK code. */
diff --git a/cores/esp8266/core_esp8266_postmortem.c b/cores/esp8266/core_esp8266_postmortem.c
index 3878cf1b9d..d0d5cbbf33 100644
--- a/cores/esp8266/core_esp8266_postmortem.c
+++ b/cores/esp8266/core_esp8266_postmortem.c
@@ -32,8 +32,6 @@
 
 extern void __real_system_restart_local();
 
-extern cont_t* g_pcont;
-
 // These will be pointers to PROGMEM const strings
 static const char* s_panic_file = 0;
 static int s_panic_line = 0;
diff --git a/cores/esp8266/coredecls.h b/cores/esp8266/coredecls.h
index 9665fdc2fb..4465fa8153 100644
--- a/cores/esp8266/coredecls.h
+++ b/cores/esp8266/coredecls.h
@@ -8,6 +8,8 @@ extern "C" {
 
 // TODO: put declarations here, get rid of -Wno-implicit-function-declaration
 
+#include <cont.h> // g_pcont declaration
+
 extern bool timeshift64_is_set;
 
 void esp_yield();
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
index 5b99b187b0..ebfabc08cc 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
@@ -1,23 +1,48 @@
+/*
+ ESP8266WiFiSTA-WPS.cpp - WiFi library for esp8266
+
+ Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.
+ This file is part of the esp8266 core for Arduino environment.
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+ Reworked on 28 Dec 2015 by Markus Sattler
+
+ */
+
 
 #include "ESP8266WiFi.h"
 #include "ESP8266WiFiGeneric.h"
 #include "ESP8266WiFiSTA.h"
 
-void wifi_wps_status_cb(wps_cb_status status);
-
 /**
  * WPS config
  * so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
  * @return ok
  */
-bool beginWPSConfig(void) {
+bool ESP8266WiFiSTAClass::beginWPSConfig(void) {
+
+    // SYS ram is used by WPS, let's configure user stack inside user's HEAP
+    disable_extra4k_at_link_time();
 
     if(!WiFi.enableSTA(true)) {
         // enable STA failed
         return false;
     }
 
-    WiFi.disconnect();
+    disconnect();
 
     DEBUGV("wps begin\n");
 
@@ -32,7 +57,7 @@ bool beginWPSConfig(void) {
         return false;
     }
 
-    if(!wifi_set_wps_cb((wps_st_cb_t) &wifi_wps_status_cb)) {
+    if(!wifi_set_wps_cb((wps_st_cb_t) &WPSStatusCB)) {
         DEBUGV("wps cb failed\n");
         return false;
     }
@@ -52,7 +77,7 @@ bool beginWPSConfig(void) {
  * WPS callback
  * @param status wps_cb_status
  */
-void wifi_wps_status_cb(wps_cb_status status) {
+void ESP8266WiFiSTAClass::WPSStatusCB(wps_cb_status status) {
     DEBUGV("wps cb status: %d\r\n", status);
     switch(status) {
         case WPS_CB_ST_SUCCESS:
@@ -81,4 +106,3 @@ void wifi_wps_status_cb(wps_cb_status status) {
 
     esp_schedule(); // resume the beginWPSConfig function
 }
-
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index 22bf10c519..fc103713ee 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -87,20 +87,19 @@ class ESP8266WiFiSTAClass {
 
     protected:
 
-      static bool _useStaticIp;
+        static bool _useStaticIp;
 
     // ----------------------------------------------------------------------------------------------
     // ------------------------------------ STA remote configure  -----------------------------------
     // ----------------------------------------------------------------------------------------------
 
-    public:
+    protected:
+    
+        static void WPSStatusCB(wps_cb_status status);
 
-        inline bool beginWPSConfig(void) __attribute__((always_inline))
-        {
-            disable_extra4k_at_link_time(); // this call must always be inlined
-            return ::beginWPSConfig();
-        }
+    public:
 
+        bool beginWPSConfig(void);
         bool beginSmartConfig();
         bool stopSmartConfig();
         bool smartConfigDone();
diff --git a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
index 0e28295520..595f2ce87a 100644
--- a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
+++ b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
@@ -1259,8 +1259,6 @@ bool WiFiClientSecure::loadPrivateKey(Stream& stream, size_t size) {
 // SSL debugging which should focus on the WiFiClientBearSSL objects.
 
 extern "C" {
-#include <cont.h>
-  extern cont_t *g_pcont;
   extern size_t br_esp8266_stack_proxy_usage();
 
   void _BearSSLCheckStack(const char *fcn, const char *file, int line) {
diff --git a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
index d679de10bd..44c7cff444 100644
--- a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
+++ b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
@@ -15,8 +15,6 @@
 
 #define USE_WPS 0 // try me with 0 or 1
 
-extern cont_t* g_pcont;
-
 void setup() {
 
   Serial.begin(115200);

From 6f7286ea0cf350b6506d8bb3a2325e03a0153b0c Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 14:49:24 +0200
Subject: [PATCH 05/13] (WIP) one more pass - need to recheck weak,alias at the
 light of the new building process - need to convert the example to host test

---
 cores/esp8266/coredecls.h                              |  2 --
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp       |  1 +
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h             |  1 -
 libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp  |  1 +
 .../esp8266/examples/extra4kchecker/extra4kchecker.ino | 10 +++++++---
 platform.txt                                           |  2 --
 6 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/cores/esp8266/coredecls.h b/cores/esp8266/coredecls.h
index 4465fa8153..39cedf557c 100644
--- a/cores/esp8266/coredecls.h
+++ b/cores/esp8266/coredecls.h
@@ -16,8 +16,6 @@ void esp_yield();
 void esp_schedule();
 void tune_timeshift64 (uint64_t now_us);
 void settimeofday_cb (void (*cb)(void));
-
-// calls to this function must *always* be inlined
 void disable_extra4k_at_link_time (void) __attribute__((noinline));
 
 #ifdef __cplusplus
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
index ebfabc08cc..854410d154 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
@@ -26,6 +26,7 @@
 #include "ESP8266WiFi.h"
 #include "ESP8266WiFiGeneric.h"
 #include "ESP8266WiFiSTA.h"
+#include "coredecls.h" // disable_extra4k_at_link_time()
 
 /**
  * WPS config
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index fc103713ee..52714684df 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -27,7 +27,6 @@
 #include "ESP8266WiFiType.h"
 #include "ESP8266WiFiGeneric.h"
 #include "user_interface.h"
-#include "coredecls.h" // disable_extra4k_at_link_time()
 
 extern bool beginWPSConfig(void);
 
diff --git a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
index 595f2ce87a..f946ae6ef1 100644
--- a/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
+++ b/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.cpp
@@ -41,6 +41,7 @@ extern "C" {
 #include "lwip/netif.h"
 #include "include/ClientContext.h"
 #include "c_types.h"
+#include "coredecls.h"
 
 namespace BearSSL {
 
diff --git a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
index 44c7cff444..e8130d0aa5 100644
--- a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
+++ b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
@@ -28,12 +28,16 @@ void setup() {
 
   Serial.printf("FreeHeap: %d (~52112 without WPS, ~46832 with)\n", ESP.getFreeHeap());
 
-#if USE_WPS
+  #if USE_WPS
+
   Serial.printf("starting WPS...\n");
   Serial.printf("wps: %d\n", WiFi.beginWPSConfig());
-#else
+
+  #else
+
   Serial.printf("done\n");
-#endif
+
+  #endif
 }
 
 void loop() {
diff --git a/platform.txt b/platform.txt
index 83e1d72bf2..a319e4f6f6 100644
--- a/platform.txt
+++ b/platform.txt
@@ -91,11 +91,9 @@ recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpreprocessor
 recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.S.flags} -DF_CPU={build.f_cpu} {build.lwip_flags} {build.debug_port} {build.debug_level} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} -DARDUINO_BOARD="{build.board}" {build.led} {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Create archives
-#recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/arduino.ar" "{object_file}"
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}"
 
 ## Combine gc-sections, archives, and objects
-#recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{build.path}/arduino.ar" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
 recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" "-L{build.path}" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
 
 ## Create eeprom

From 12f412dc3c117f10ed15b2edc91cd95228e00ce1 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 14:55:39 +0200
Subject: [PATCH 06/13] clean (wip'ed) declaration

---
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index 52714684df..aea4c68601 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -28,8 +28,6 @@
 #include "ESP8266WiFiGeneric.h"
 #include "user_interface.h"
 
-extern bool beginWPSConfig(void);
-
 class ESP8266WiFiSTAClass {
         // ----------------------------------------------------------------------------------------------
         // ---------------------------------------- STA function ----------------------------------------

From 3259bbc8144ef2458be759e5799e254884ce9d56 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 16:01:20 +0200
Subject: [PATCH 07/13] removed example, added device tests

---
 .../extra4kchecker/extra4kchecker.ino         | 44 -------------------
 .../libraries/BSTest/library.properties       |  1 -
 .../test_stack_in_heap/test_stack_in_heap.ino | 24 ++++++++++
 .../test_stack_in_sys/test_stack_in_sys.ino   | 21 +++++++++
 4 files changed, 45 insertions(+), 45 deletions(-)
 delete mode 100644 libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
 create mode 100644 tests/device/test_stack_in_heap/test_stack_in_heap.ino
 create mode 100644 tests/device/test_stack_in_sys/test_stack_in_sys.ino

diff --git a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino b/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
deleted file mode 100644
index e8130d0aa5..0000000000
--- a/libraries/esp8266/examples/extra4kchecker/extra4kchecker.ino
+++ /dev/null
@@ -1,44 +0,0 @@
-
-/*
-   This is a debugging / validation test only
-
-   It demonstrates the effect of calling
-       disable_extra4k_at_link_time()
-
-   Currently only WPS is using that call
-
-   released to public domain
-*/
-
-#include <ESP8266WiFi.h>
-#include <cont.h>
-
-#define USE_WPS 0 // try me with 0 or 1
-
-void setup() {
-
-  Serial.begin(115200);
-  Serial.setDebugOutput(true);
-  WiFi.mode(WIFI_STA);
-  bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
-  Serial.printf("\nUsing sys stack: %s\ncont: %p (USER:0x3ffe SYS:0x3fff)\n"
-                "check https://github.com/esp8266/esp8266-wiki/wiki/Memory-Map)\n",
-                sysstack ? "YES" : "NO",
-                g_pcont);
-
-  Serial.printf("FreeHeap: %d (~52112 without WPS, ~46832 with)\n", ESP.getFreeHeap());
-
-  #if USE_WPS
-
-  Serial.printf("starting WPS...\n");
-  Serial.printf("wps: %d\n", WiFi.beginWPSConfig());
-
-  #else
-
-  Serial.printf("done\n");
-
-  #endif
-}
-
-void loop() {
-}
diff --git a/tests/device/libraries/BSTest/library.properties b/tests/device/libraries/BSTest/library.properties
index f2399ca939..cd65913497 100644
--- a/tests/device/libraries/BSTest/library.properties
+++ b/tests/device/libraries/BSTest/library.properties
@@ -7,4 +7,3 @@ paragraph=
 category=Uncategorized
 url=
 architectures=esp8266
-dot_a_linkage=true
diff --git a/tests/device/test_stack_in_heap/test_stack_in_heap.ino b/tests/device/test_stack_in_heap/test_stack_in_heap.ino
new file mode 100644
index 0000000000..02cb11e9f1
--- /dev/null
+++ b/tests/device/test_stack_in_heap/test_stack_in_heap.ino
@@ -0,0 +1,24 @@
+#include <BSTest.h>
+
+BS_ENV_DECLARE();
+
+#include <ESP8266WiFi.h>
+#include <coredecls.h>
+
+void setup()
+{
+    Serial.begin(115200);
+    BS_RUN(Serial);
+}
+
+TEST_CASE("stack in user's HEAP ram", "[bs]")
+{
+    bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
+    CHECK(!sysstack);
+}
+
+void loop ()
+{
+    // WPS I link you !
+    WiFi.beginWPSConfig();
+}
diff --git a/tests/device/test_stack_in_sys/test_stack_in_sys.ino b/tests/device/test_stack_in_sys/test_stack_in_sys.ino
new file mode 100644
index 0000000000..6a1595c5ad
--- /dev/null
+++ b/tests/device/test_stack_in_sys/test_stack_in_sys.ino
@@ -0,0 +1,21 @@
+#include <BSTest.h>
+
+BS_ENV_DECLARE();
+
+#include <cont.h>
+
+void setup()
+{
+    Serial.begin(115200);
+    BS_RUN(Serial);
+}
+
+TEST_CASE("stack in SYS ram", "[bs]")
+{
+    bool sysstack = (((unsigned long)g_pcont) >> 16) == 0x3fff;
+    CHECK(sysstack);
+}
+
+void loop ()
+{
+}

From 446220b82b706bf4a677222ceb9b1fe98dddab4f Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 16:03:49 +0200
Subject: [PATCH 08/13] minimize commits footprint

---
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index aea4c68601..d7ade712dd 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -28,6 +28,7 @@
 #include "ESP8266WiFiGeneric.h"
 #include "user_interface.h"
 
+
 class ESP8266WiFiSTAClass {
         // ----------------------------------------------------------------------------------------------
         // ---------------------------------------- STA function ----------------------------------------

From c64f994100761dd19c5f4e2623eb93ea1cd3a8c3 Mon Sep 17 00:00:00 2001
From: david gauchard <gauchard@laas.fr>
Date: Thu, 9 Aug 2018 23:42:51 +0200
Subject: [PATCH 09/13] boards gen: deprecated option

---
 tools/boards.txt.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/boards.txt.py b/tools/boards.txt.py
index 221e6bfdc7..6fc9c787b7 100755
--- a/tools/boards.txt.py
+++ b/tools/boards.txt.py
@@ -1472,7 +1472,7 @@ def usage (name,ret):
         nofloat=True
 
     elif o in ("--noextra4kheap", "--allowWPS"):
-        print('option ' + o + ' is now useless')
+        print('option ' + o + ' is now deprecated, without effect, and will be removed')
 
     elif o in ("--ldshow"):
         ldshow = True

From cdba9b4751c45e704a8c3279d62d92d9f4bd543a Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Fri, 10 Aug 2018 12:00:57 +0200
Subject: [PATCH 10/13] some comment updates and fixes from @devyte's review

---
 cores/esp8266/core_esp8266_app_entry_noextra4k.cpp | 1 -
 cores/esp8266/core_esp8266_main.cpp                | 2 +-
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp   | 6 ++++--
 libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h         | 4 ----
 4 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
index 1aa380459d..f2f9bffa32 100644
--- a/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
+++ b/cores/esp8266/core_esp8266_app_entry_noextra4k.cpp
@@ -10,7 +10,6 @@
 #include "cont.h"
 #include "coredecls.h"
 
-// callers to this function must *always* be inlined
 void disable_extra4k_at_link_time (void)
 {
     /*
diff --git a/cores/esp8266/core_esp8266_main.cpp b/cores/esp8266/core_esp8266_main.cpp
index f64d60079c..137559b738 100644
--- a/cores/esp8266/core_esp8266_main.cpp
+++ b/cores/esp8266/core_esp8266_main.cpp
@@ -183,7 +183,7 @@ void init_done() {
 
    (note: setting app_entry() itself as "weak" is not sufficient and always
     ends up with the other "noextra4k" one linked, maybe because it has a
-    default value in linker scripts).
+    default ENTRY(app_entry) value in linker scripts).
 
    References:
    https://github.com/esp8266/Arduino/pull/4553
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
index 854410d154..c7a92765be 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA-WPS.cpp
@@ -28,6 +28,8 @@
 #include "ESP8266WiFiSTA.h"
 #include "coredecls.h" // disable_extra4k_at_link_time()
 
+static void wifi_wps_status_cb(wps_cb_status status);
+
 /**
  * WPS config
  * so far only WPS_TYPE_PBC is supported (SDK 1.2.0)
@@ -58,7 +60,7 @@ bool ESP8266WiFiSTAClass::beginWPSConfig(void) {
         return false;
     }
 
-    if(!wifi_set_wps_cb((wps_st_cb_t) &WPSStatusCB)) {
+    if(!wifi_set_wps_cb((wps_st_cb_t) &wifi_wps_status_cb)) {
         DEBUGV("wps cb failed\n");
         return false;
     }
@@ -78,7 +80,7 @@ bool ESP8266WiFiSTAClass::beginWPSConfig(void) {
  * WPS callback
  * @param status wps_cb_status
  */
-void ESP8266WiFiSTAClass::WPSStatusCB(wps_cb_status status) {
+void wifi_wps_status_cb(wps_cb_status status) {
     DEBUGV("wps cb status: %d\r\n", status);
     switch(status) {
         case WPS_CB_ST_SUCCESS:
diff --git a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
index d7ade712dd..58b76ef5ee 100644
--- a/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
+++ b/libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h
@@ -91,10 +91,6 @@ class ESP8266WiFiSTAClass {
     // ------------------------------------ STA remote configure  -----------------------------------
     // ----------------------------------------------------------------------------------------------
 
-    protected:
-    
-        static void WPSStatusCB(wps_cb_status status);
-
     public:
 
         bool beginWPSConfig(void);

From 67405c18c0dc5dbcd7d8ded7741cc3f819696b96 Mon Sep 17 00:00:00 2001
From: david gauchard <gauchard@laas.fr>
Date: Thu, 16 Aug 2018 16:10:59 +0200
Subject: [PATCH 11/13] updates from second @igrr's review

---
 cores/esp8266/cont.h                | 6 +-----
 cores/esp8266/core_esp8266_main.cpp | 2 +-
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/cores/esp8266/cont.h b/cores/esp8266/cont.h
index 13b51babe6..c3a36eba11 100644
--- a/cores/esp8266/cont.h
+++ b/cores/esp8266/cont.h
@@ -49,11 +49,7 @@ typedef struct cont_ {
         unsigned* struct_start;
 } cont_t;
 
-/* Not static, used in core_esp8266_postmortem.c.
- * Placed into noinit section because we assign value to this variable
- * before .bss is zero-filled, and need to preserve the value.
- */
-extern cont_t* g_pcont __attribute__((section(".noinit")));
+extern cont_t* g_pcont;
 
 // Initialize the cont_t structure before calling cont_run
 void cont_init(cont_t*);
diff --git a/cores/esp8266/core_esp8266_main.cpp b/cores/esp8266/core_esp8266_main.cpp
index f64d60079c..fe88804f58 100644
--- a/cores/esp8266/core_esp8266_main.cpp
+++ b/cores/esp8266/core_esp8266_main.cpp
@@ -48,7 +48,7 @@ extern void (*__init_array_end)(void);
 /* Not static, used in Esp.cpp */
 struct rst_info resetInfo;
 
-/* Not static, used in core_esp8266_postmortem.c.
+/* Not static, used in core_esp8266_postmortem.c and other places.
  * Placed into noinit section because we assign value to this variable
  * before .bss is zero-filled, and need to preserve the value.
  */

From 8ec3504fe346be8a02b02bc4a56845db12c4a58a Mon Sep 17 00:00:00 2001
From: david gauchard <gauchard@laas.fr>
Date: Thu, 16 Aug 2018 16:12:48 +0200
Subject: [PATCH 12/13] updates from second @igrr's review

---
 doc/faq/readme.rst | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/doc/faq/readme.rst b/doc/faq/readme.rst
index b4ff2659e6..17d8309ca5 100644
--- a/doc/faq/readme.rst
+++ b/doc/faq/readme.rst
@@ -55,16 +55,19 @@ How can I get some extra KBs in flash ?
 About WPS
 ~~~~~~~~~
 
-In release 2.4.2 only, WPS is disabled by default.  To enable WPS, use this
-boards generator option:
+From release 2.4.2 and ahead, not using WPS will give an exra ~4.5KB in
+heap.
+
+In release 2.4.2 only, WPS is disabled by default and the board generator is
+required to enable it:
 
 ``./tools/boards.txt.py --allowWPS --boardsgen``
 
 `Read more <a05-board-generator.rst>`__.
 
-From release 2.4.2 and ahead, using WPS will reduce available heap space to
-user by around 4.5KB.  In other words, from release 2.4.2 without using WPS,
-an extra ~4.5KB is available in user's heap space.
+This manual selection is not needed starting from 2.5.0 (and in git
+version).  WPS is always available, and not using it will give an extra
+~4.5KB compared to releases until 2.4.1 included.
 
 This Arduino library doesn't work on ESP. How do I make it work?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From eb18c5b1575d2a801a7b91048fbbfa4fb11faa9d Mon Sep 17 00:00:00 2001
From: david gauchard <gauchard@laas.fr>
Date: Thu, 16 Aug 2018 23:42:16 +0200
Subject: [PATCH 13/13] remove duplicate -L option

---
 platform.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/platform.txt b/platform.txt
index a319e4f6f6..9158c3a46d 100644
--- a/platform.txt
+++ b/platform.txt
@@ -94,7 +94,7 @@ recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.fla
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}"
 
 ## Combine gc-sections, archives, and objects
-recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" "-L{build.path}" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
+recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"
 
 ## Create eeprom
 recipe.objcopy.eep.pattern=