optionally allow WPS (#4889)

Author: d-a-v

cores/esp8266/core_esp8266_main.cpp

@@ -156,11 +156,59 @@ void init_done() {
  * Peripherals (except for SPI0 and UART0) are not initialized.
  * This function does not return.
  */
+/*
+   A bit of explanation for this entry point:
+
+   SYS is the SDK task/context used by the upperlying system to run its
+   administrative tasks (at least WLAN and lwip's receive callbacks and
+   Ticker).  NONOS-SDK is designed to run user's non-threaded code in
+   another specific task/context with its own stack in BSS.
+
+   Some clever fellows found that the SYS stack was a large and quite unused
+   piece of ram that we could use for the user's stack instead of using user's
+   main memory, thus saving around 4KB on ram/heap.
+
+   A problem arose later, which is that this stack can heavily be used by
+   the SDK for some features.  One of these features is WPS.  We still don't
+   know if other features are using this, or if this memory is going to be
+   used in future SDK releases.
+
+   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.
+
+   References:
+   https://github.com/esp8266/Arduino/pull/4553
+   https://github.com/esp8266/Arduino/pull/4622
+   https://github.com/esp8266/Arduino/issues/4779
+   https://github.com/esp8266/Arduino/pull/4889
+
+*/
+
+#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)
 {
-    /* Allocate continuation context on this stack, and save pointer to it. */
+#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();
 }

doc/faq/readme.rst

@@ -40,6 +40,22 @@ entering an issue report, please perform initial troubleshooting.
 
 `Read more <a02-my-esp-crashes.rst>`__.
 
+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``
+
+Why can't I use 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:
+
+``./tools/boards.txt.py --allowWPS --allgen``
+
 This Arduino library doesn't work on ESP. How do I make it work?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.cpp

@@ -571,6 +571,9 @@ 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);
 
 /**
@@ -650,7 +653,7 @@ void wifi_wps_status_cb(wps_cb_status status) {
     esp_schedule(); // resume the beginWPSConfig function
 }
 
-
+#endif // NO_EXTRA_4K_HEAP
 
 bool ESP8266WiFiSTAClass::_smartConfigStarted = false;
 bool ESP8266WiFiSTAClass::_smartConfigDone = false;

libraries/ESP8266WiFi/src/ESP8266WiFiSTA.h

@@ -26,6 +26,7 @@
 
 #include "ESP8266WiFiType.h"
 #include "ESP8266WiFiGeneric.h"
+#include "user_interface.h"
 
 
 class ESP8266WiFiSTAClass {
@@ -92,7 +93,13 @@ 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();
+        }
+#endif
 
         bool beginSmartConfig();
         bool stopSmartConfig();

platform.txt

@@ -25,14 +25,15 @@ 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
 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} -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} {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.S.cmd=xtensa-lx106-elf-gcc
 compiler.S.flags=-c -g -x assembler-with-cpp -MMD -mlongcalls
@@ -43,7 +44,7 @@ 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} -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} {build.noextra4kheap} -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
 

tools/boards.txt.py

@@ -1236,6 +1236,9 @@ def all_boards ():
         if nofloat:
             print id + '.build.float='
 
+        if noextra4kheap:
+            print id + '.build.noextra4kheap=-DNO_EXTRA_4K_HEAP'
+
         print ''
 
     if boardsgen:
@@ -1253,11 +1256,8 @@ def package ():
 
     if packagegen:
         pkgfname_read = pkgfname + '.orig'
-        # check if backup already exists
         if os.path.isfile(pkgfname_read):
-            print "package file is in the way, please move it"
-            print "    %s" % pkgfname_read
-            sys.exit(1)
+            os.remove(pkgfname_read)
         os.rename(pkgfname, pkgfname_read)
 
     # read package file
@@ -1333,6 +1333,8 @@ 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 ""
@@ -1376,6 +1378,7 @@ def usage (name,ret):
 led_default = 2
 led_max = 16
 nofloat = False
+noextra4kheap = False
 ldgen = False
 ldshow = False
 boardsgen = False
@@ -1391,6 +1394,7 @@ def usage (name,ret):
 try:
     opts, args = getopt.getopt(sys.argv[1:], "h",
         [ "help", "lwip=", "led=", "speed=", "board=", "customspeed=", "nofloat",
+          "noextra4kheap", "allowWPS",
           "ld", "ldgen", "boards", "boardsgen", "package", "packagegen", "doc", "docgen",
           "allgen"] )
 except getopt.GetoptError as err:
@@ -1434,6 +1438,9 @@ def usage (name,ret):
     elif o in ("--nofloat"):
         nofloat=True
 
+    elif o in ("--noextra4kheap", "--allowWPS"):
+        noextra4kheap=True
+
     elif o in ("--ldshow"):
         ldshow = True
 

tools/sdk/include/user_interface.h

@@ -575,13 +575,27 @@ enum wps_cb_status {
     WPS_CB_ST_UNK,
 };
 
+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);
-
-typedef void (*wps_st_cb_t)(int status);
 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);