* Upgrade to GCC 9.1 toolchain * Rebuilt using pure GNU binutils and GCC Remove dependencies on earlier forked GNU utilities (gcc-xtensa, binutils-gdb-xtensa) and just use GCC sources, unmodified (except for patches in the esp-quick-toolchain directories). * Rebuild bearssl using new toolchain * Fix GDBstub linkage options GDB works with pure GNU GCC and pure GNU binutils now. Still warnings galore, but tested with the example sketch in the docs. * Fix digitalRead alias warning * Remove gdb stub warnings w/a pragma * Fix deprecated implicit copy ctors in IP code Fix some warnings present in GCC8/9 in the IPAddress code In AddressListIterator there was a copy constructor which simply copied the structure bit-for-bit. That's the default operation, so remove it to avoid the warning there. IPAddress, add a default copy constructor since the other copy constructors are simply parsing from one format into a native ip_addr_t. @d-a-v, can you give these a look over and see if they're good (since IP stuff is really your domain). * Fix AxTLS alias function defs to match real code * Fix WiFiClientSecure implicit default copy ctor These both use shared-ptrs to handle refcnts to allocated data, so using the default copy constructor is fine (and has been in use for a long time). * Dummy size for heap to avoid GCC 8/9 warnings Make GCC think _heap_start is large enough to avoid the basic (and incorrect) bounds-checking warnings it produces. The size chosen is arbitrary and does not affect the actual size of the heap in any way. * Make heap an undefined extend array Instead of a bogus size, use an indefinite size for the heap to avoid GCC warnings * Trivial tab to space fix * Update SDFat to remove FatFile warnings * Fix ticker function cast warnings in GCC 9 The callback function is defined to take a (void*) as parameter, but our templates let users use anything that fits inside sizeof(void*) to be passed in. Add pragmas to stop GCC warnings about this, since we already check the size of the type will fit in the allocated space. * Remove GCC support fcn that's in ROM Manually delete the divdi3.so from the libgcc.a library by running the updated EQT's 9.1-post script. * Make exceptions work again, get std::regex up Exceptions are broken on all builds (GCC4.8-9.1) due to the removal of the PROGMEM non-32b read exception handler (added in the unstable pre3.0.0). Build the exception code with -mforce-l32 and patch accordingly to avoid LoadStore errors. Apply patches to select portions of the regex lib which use _stype_ (which is now in flash). * Rebuild Bearssl using latest GCC push * Automate building of BearSSL and LWIP w/new toolchain * Workaround g++ template section problem for exception strings G++ seems to throw out the section attributes for templates. This means that the __EXCSTR(a synonym for "PSTR()") is ignored and exception.what strings are stored in RODATA, eating up RAM. Workaround by using the linker to place the strings keying off their name ("*__exception_what__*"). * Rebuild moving exception.what to unique names Exception.whats are now all in __exception_what__ and can be moved by the linker to flash. Works aroung G++ issue with segments being lost in templates. * Rebuild with new LWIP locking * Update to latest libs, save iram Move two GCC FP support routines out of iram since they are in ROM already, saving some add'l IRAM. Same list as gcc 4.8. * Update BearSSL to latest release * Fix umm_perf reference to ROM function * Fix "reinterpret_case is not a constexpr" error In GCC 9 (and 8 from what I read on SO), a cast of a const int to a function pointer (via explicit or implicit reinterpret_cast) is not a constexpr. ```` /home/earle/Arduino/hardware/esp8266com/esp8266/cores/esp8266/umm_malloc/umm_performance.cpp:45:36: error: a reinterpret_cast is not a constant expression 45 | int constexpr (*_rom_putc1)(int) = (int (*)(int))(void*)0x40001dcc; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ```` Remove the constexpr, potentially increasing heap usage by 4 bytes in debug mode. * Update libc.a to latest rev * Full rebuild of toolchain and libs * Upgrade to GCC 9.2, released in August 2019 Add builds for all 5 cross-compiles to pass CI * Move to --std=gnu++14 (C++14 + GNU extensions) * Fix Ticker merge conflict * Fix json merge conflict * One more merge diff fix * Reapply Ticker.h casting warning fixes for gcc9 * Update with fixes from Sming repo for PSTR and ASM * Upgrade to -gnu4 toolchain * Move to gnu5 build with add'l softFP from ROM * Move add'l softFP from IRAM to flash Per @mikee47, we miss sone add'l soft-FP routined in the linker which makes them end up in IRAM. Move them explicitly into flash, like a couple others we have already done this for. * Move to std=c++17/c17 in platform, remove abs/round Move to C++17 and C17 standards on the compiler options. Remove "register" from core since it is deprecated. Remove the #define abs() and #define round() which a) overwrote the C stdlib definitions, poorly, and b) broke the GCC core code which used "abs" as an internal function name. Now abs() returns an integer, and not whatever was being absoluted. fabs() etc. can be used if users need fload/double suport. round() returns a double now, which is basically what it was returning in the original case since adding/subtracting by a FP. * Use std::abs/round to replace the macro definitions Per discussion w/@devyte, preserve the abs() and round() functionality via the using statement. * Remove using std::abs which conflicted with C lib headers * Add 2nd arg (exception handler) to ets_isr_t Disassembly of the ROM shows there are 2 params to the ets_isr_t callback. The first is the arg passed in, the second is a pointer to an exception frame where you can get info about when the IRQ happened. * Move the gdbstub example to a subdir The Arduino IDE and the build CI don't build it without a subdir, so make one for gdbstub's example so it's visible and tested. * Fix ets_irq_arratch redefinition and core IRQ handlers Remove a duplicated, different declaration for ets_irq_attach from ets_sys.h. It never really even matched the other declaration in the same header. Update the core to IRQ handlers to fix the prototype and include the 2nd, unused frame parameter. * Actually rebuild the libc.a using GCC 9.2 * Fix SPISlave interrupt attach's 2nd parameter * Rebuild eboot.elf with GCC 9 * Update to latest SoftwareSerial for Delegate fix * Upgrade to GCC 9.3 * Rebuild all arch toolchains * Move to GCC 10.1 * Merge master and fix eboot build GCC10 now uses `-fno-common` so the eboot global variables were being placed in IRAM. Adjust the makefile and rebuild to fix. * Built complete toolchain for all archs * Pull in latest PSTR changes and fix GCC10.1 build Somehow the prior GCC build's -mforce32 patch wasn't applying correctly, but I was still able to get a binary. Fixed. Also pulled in latest PSTR changes in progmem.h * Update platform.io to platform C/C++ standards * Use PR's toolchain in platformio build * Fix several asm warnings in PIO build * Optional stack smash protection -fstack-protector Add a menu to enable GCC's built-in stack smash protection. When a subroutine goes past its end of stack, generate a crashdump on function exit like: ```` GCC detected stack overrun Stack corrupted, stack smash detected. >>>stack>>> ctx: cont sp: 3fffff20 end: 3fffffc0 offset: 0000 3fffff20: 40202955 00000001 0000001c 4020287e 3fffff30: feefeffe 000000fd 00000000 00000000 ... <<<stack<<< ```` Disabled by default because there is a small per-function code overhead (and CPU time if the function is called very frequently and is very small). BearSSL and LWIP are not built using stack smash detection, yet. * Fix duplicated stc=gnu99/c17 in build * Dump faulting function PC in stack overflow Report a fake exception to have the exception decoder print the actual faulting function. This won't tell you where in the function the issue happened, but it will tell you the function name first and foremost. * Rebuild with Platform.io JSON tag in release tgzs
Arduino core for ESP8266 WiFi chip
Quick links
Arduino on ESP8266
This project brings support for the ESP8266 chip to the Arduino environment. It lets you write sketches, using familiar Arduino functions and libraries, and run them directly on ESP8266, with no external microcontroller required.
ESP8266 Arduino core comes with libraries to communicate over WiFi using TCP and UDP, set up HTTP, mDNS, SSDP, and DNS servers, do OTA updates, use a file system in flash memory, and work with SD cards, servos, SPI and I2C peripherals.
Contents
- Installing options:
- Documentation
- Issues and support
- Contributing
- License and credits
Installing with Boards Manager
Starting with 1.6.4, Arduino allows installation of third-party platform packages using Boards Manager. We have packages available for Windows, Mac OS, and Linux (32 and 64 bit).
- Install the current upstream Arduino IDE at the 1.8.9 level or later. The current version is on the Arduino website.
- Start Arduino and open the Preferences window.
- Enter
https://arduino.esp8266.com/stable/package_esp8266com_index.json
into the Additional Board Manager URLs field. You can add multiple URLs, separating them with commas. - Open Boards Manager from Tools > Board menu and install esp8266 platform (and don't forget to select your ESP8266 board from Tools > Board menu after installation).
Latest release 
Boards manager link: https://arduino.esp8266.com/stable/package_esp8266com_index.json
Documentation: https://arduino-esp8266.readthedocs.io/en/2.7.2/
Using git version
Also known as latest git or master branch.
- Install the current upstream Arduino IDE at the 1.8 level or later. The current version is on the Arduino website.
- Follow the instructions in the documentation.
Using PlatformIO
PlatformIO is an open source ecosystem for IoT development with a cross-platform build system, a library manager, and full support for Espressif (ESP8266) development. It works on the following popular host operating systems: macOS, Windows, Linux 32/64, and Linux ARM (like Raspberry Pi, BeagleBone, CubieBoard).
- What is PlatformIO?
- PlatformIO IDE
- PlatformIO Core (command line tool)
- Advanced usage - custom settings, uploading to SPIFFS, Over-the-Air (OTA), staging version
- Integration with Cloud and Standalone IDEs - Cloud9, Codeanywhere, Eclipse Che (Codenvy), Atom, CLion, Eclipse, Emacs, NetBeans, Qt Creator, Sublime Text, VIM, Visual Studio, and VSCode
- Project Examples
Building with make
makeEspArduino is a generic makefile for any ESP8266 Arduino project. Using make instead of the Arduino IDE makes it easier to do automated and production builds.
Documentation
Documentation for latest development version: https://arduino-esp8266.readthedocs.io/en/latest/
Issues and support
ESP8266 Community Forum is a well-established community for questions and answers about Arduino for ESP8266. Stackoverflow is also an alternative. If you need help, have a "How do I..." type question, have a problem with a 3rd party library not hosted in this repo, or just want to discuss how to approach a problem, please ask there.
If you find the forum useful, please consider supporting it with a donation.
If you encounter an issue which you think is a bug in the ESP8266 Arduino Core or the associated libraries, or if you want to propose an enhancement, you are welcome to submit it here on Github: https://github.com/esp8266/Arduino/issues.
Please provide as much context as possible, as well as the information requested in the issue template:
- ESP8266 Arduino core version which you are using (you can check it in Boards Manager)
- your sketch code; please wrap it into a code block, see Github markdown manual
- when encountering an issue that happens at run time, attach the serial output. Wrap it into a code block, just like the code.
- for issues that happen at compile time, enable verbose compiler output in the IDE preferences, and attach that output (also inside a code block)
- ESP8266 development board model
- IDE settings (board choice, flash size)
- etc
Contributing
For minor fixes of code and documentation, please go ahead and submit a pull request. A gentle introduction to the process can be found here.
Check out the list of issues that are easy to fix — easy issues pending. Working on them is a great way to move the project forward.
Larger changes (rewriting parts of existing code from scratch, adding new functions to the core, adding new libraries) should generally be discussed by opening an issue first. PRs with such changes require testing and approval.
Feature branches with lots of small commits (especially titled "oops", "fix typo", "forgot to add file", etc.) should be squashed before opening a pull request. At the same time, please refrain from putting multiple unrelated changes into a single pull request.
License and credits
Arduino IDE is developed and maintained by the Arduino team. The IDE is licensed under GPL.
ESP8266 core includes an xtensa gcc toolchain, which is also under GPL.
Esptool.py was initially created by Fredrik Ahlberg (@themadinventor, @kongo), and is currently maintained by Angus Gratton (@projectgus) under GPL 2.0 license.
Espressif SDK included in this build is under Espressif MIT License.
ESP8266 core files are licensed under LGPL.
SPI Flash File System (SPIFFS) written by Peter Andersson is used in this project. It is distributed under the MIT license.
umm_malloc memory management library written by Ralph Hempel is used in this project. It is distributed under the MIT license.
SoftwareSerial library and examples written by Peter Lerup. Distributed under LGPL 2.1.
axTLS library written by Cameron Rich, built from https://github.com/igrr/axtls-8266, is used in this project. It is distributed under BSD license.
BearSSL library written by Thomas Pornin, built from https://github.com/earlephilhower/bearssl-esp8266, is used in this project. It is distributed under the MIT License.
LittleFS library written by ARM Limited and released under the BSD 3-clause license.
uzlib library written and (c) 2014-2018 Paul Sokolovsky, licensed under the ZLib license (https://www.zlib.net/zlib_license.html). uzlib is based on: tinf library by Joergen Ibsen (Deflate decompression); Deflate Static Huffman tree routines by Simon Tatham; LZ77 compressor by Paul Sokolovsky; with library integrated and maintained by Paul Sokolovsky.
Other useful links
Serial Monitor Arduino IDE plugin Original discussion here, quick download there.