Go compiler for small devices, based on LLVM.
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deadprogram and aykevl pca10031: add support for PCA10031 nrf51 wireless dongle
Signed-off-by: Ron Evans <ron@hybridgroup.com>
Latest commit ce0ad1d Nov 20, 2018
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compiler arm: implement arm.ReadRegister Nov 18, 2018
docs pca10031: add support for PCA10031 nrf51 wireless dongle Nov 21, 2018
interp interp: do not try to interpret functions with an inttoptr instruction Nov 18, 2018
ir ir: do not throw an error on unknown conversions Oct 31, 2018
lib all: use compiler-rt for builtins Oct 7, 2018
src pca10031: add support for PCA10031 nrf51 wireless dongle Nov 21, 2018
targets pca10031: add support for PCA10031 nrf51 wireless dongle Nov 21, 2018
testdata runtime: implement a simple mark/sweep garbage collector Nov 18, 2018
tools avr: add support for the digispark Nov 20, 2018
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.travis.yml pca10031: add support for PCA10031 nrf51 wireless dongle Nov 21, 2018
Dockerfile all: add support to Dockerfile for AVR and ARM targets Nov 15, 2018
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Makefile avr: add support for the digispark Nov 20, 2018
README.md docs: rename readme extension to .md Oct 25, 2018
binutils.go compiler: add -size flag to replace size utility Sep 17, 2018
buildcache.go all: use compiler-rt for builtins Oct 7, 2018
builtins.go main: add aeabi builtins to arm targets Oct 7, 2018
colorwriter.go all: implement gdb sub-command for easy debugging Oct 3, 2018
main.go targets: make compiler runtime selection more configurable Nov 19, 2018
main_test.go runtime: implement a simple mark/sweep garbage collector Nov 18, 2018
target.go targets: let specific targets inherit more general targets Nov 19, 2018


TinyGo - Go compiler for microcontrollers

Documentation Status Build Status

We never expected Go to be an embedded language and so it's got serious problems [...].

-- Rob Pike, GopherCon 2014 Opening Keynote

TinyGo is a project to bring Go to microcontrollers and small systems with a single processor core. It is similar to emgo but a major difference is that I want to keep the Go memory model (which implies garbage collection of some sort). Another difference is that TinyGo uses LLVM internally instead of emitting C, which hopefully leads to smaller and more efficient code and certainly leads to more flexibility.

My original reasoning was: if Python can run on microcontrollers, then certainly Go should be able to and run on even lower level micros.

Example program (blinky):

import (

func main() {
	led := machine.GPIO{machine.LED}
	led.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
	for {
		time.Sleep(time.Millisecond * 1000)

		time.Sleep(time.Millisecond * 1000)

Currently supported features:

  • control flow
  • many (but not all) basic types: most ints, floats, strings, structs
  • function calling
  • interfaces for basic types (with type switches and asserts)
  • goroutines (very initial support)
  • function pointers (non-blocking)
  • interface methods
  • standard library (but most packages won't work due to missing language features)
  • slices (partially)
  • maps (very rough, unfinished)
  • defer
  • closures
  • bound methods
  • complex numbers (except for arithmetic)

Not yet supported:

  • complex arithmetic
  • garbage collection
  • recover
  • channels
  • introspection (if it ever gets implemented)
  • ...


See the installation instructions.

Running with Docker

A docker container exists for easy access to the tinygo CLI:

$ docker run --rm -v $(pwd):/src tinygo/tinygo build -o /src/wasm.wasm -target wasm examples/wasm

Note that you cannot run tinygo flash from inside the docker container, so it is less useful for microcontroller development.

Supported targets

The following architectures/systems are currently supported:

  • ARM (Cortex-M)
  • AVR (Arduino Uno)
  • Linux
  • WebAssembly

For more information, see this list of targets and boards. Pull requests for broader support are welcome!

Analysis and optimizations

The goal is to reduce code size (and increase performance) by performing all kinds of whole-program analysis passes. The official Go compiler doesn't do a whole lot of analysis (except for escape analysis) because it needs to be fast, but embedded programs are necessarily smaller so it becomes practical. And I think especially program size can be reduced by a large margin when actually trying to optimize for it.

Implemented compiler passes:

  • Analyse which functions are blocking. Blocking functions are functions that call sleep, chan send, etc. Its parents are also blocking.
  • Analyse whether the scheduler is needed. It is only needed when there are go statements for blocking functions.
  • Analyse whether a given type switch or type assert is possible with type-based alias analysis. I would like to use flow-based alias analysis in the future, if feasible.
  • Do basic dead code elimination of functions. This pass makes later passes better and probably improves compile time as well.



  • Have very small binary sizes. Don't pay for what you don't use.
  • Support for most common microcontroller boards.
  • Be usable on the web using WebAssembly.
  • Good CGo support, with no more overhead than a regular function call.
  • Support most standard library packages and compile most Go code without modification.


  • Using more than one core.
  • Be efficient while using zillions of goroutines. However, good goroutine support is certainly a goal.
  • Be as fast as gc. However, LLVM will probably be better at optimizing certain things so TinyGo might actually turn out to be faster for number crunching.
  • Be able to compile every Go program out there.


Documentation is currently maintained on a dedicated ReadTheDocs page.

Getting help

If you're looking for a more interactive way to discuss TinyGo usage or development, we have a #TinyGo channel on the Gophers Slack.

If you need an invitation for the Gophers Slack, you can generate one here which should arrive fairly quickly (under 1 min): https://invite.slack.golangbridge.org


Patches are welcome!

If you want to contribute, here are some suggestions:

  • A long tail of small (and large) language features haven't been implemented yet. In almost all cases, the compiler will show a todo: error from compiler/compiler.go when you try to use it. You can try implementing it, or open a bug report with a small code sample that fails to compile.
  • Lots of targets/boards are still unsupported. Adding an architecture often requires a few compiler changes, but if the architecture is supported you can try implementing support for a new chip or board in src/runtime. For details, see this wiki entry on adding archs/chips/boards.
  • Microcontrollers have lots of peripherals and many don't have an implementation yet in the machine package. Adding support for new peripherals is very useful.
  • Just raising bugs for things you'd like to see implemented is also a form of contributing! It helps prioritization.


This project is licensed under the BSD 3-clause license, just like the Go project itself.