It reuses libraries used by the [Go language tools](https://golang.org/pkg/go/) alongside [LLVM](http://llvm.org) to provide an alternative way to compile programs written in the Go programming language.
The above program can be compiled and run without modification on an Arduino Uno, an Adafruit ItsyBitsy M0, or any of the supported boards that have a built-in LED, just by setting the correct TinyGo compiler target. For example, this compiles and flashes an Arduino Uno:
TinyGo is very useful for compiling programs both for use in browsers (WASM) as well as for use on servers and other edge devices (WASI).
TinyGo programs can run in Fastly Compute@Edge (https://developer.fastly.com/learning/compute/go/), Fermyon Spin (https://developer.fermyon.com/spin/go-components), wazero (https://wazero.io/languages/tinygo/) and many other WebAssembly runtimes.
Here is a small TinyGo program for use by a WASI host application:
```go
package main
//go:wasm-module yourmodulename
//export add
func add(x, y uint32) uint32 {
return x + y
}
// main is required for the `wasi` target, even if it isn't used.
func main() {}
```
This compiles the above TinyGo program for use on any WASI runtime:
See the [getting started instructions](https://tinygo.org/getting-started/) for information on how to install TinyGo, as well as how to run the TinyGo compiler using our Docker container.
* 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.
Non-goals:
* 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.
## Why this project exists
> We never expected Go to be an embedded language and so its got serious problems...
-- Rob Pike, [GopherCon 2014 Opening Keynote](https://www.youtube.com/watch?v=VoS7DsT1rdM&feature=youtu.be&t=2799)
TinyGo is a project to bring Go to microcontrollers and small systems with a single processor core. It is similar to [emgo](https://github.com/ziutek/emgo) but a major difference is that we 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.
The original reasoning was: if [Python](https://micropython.org/) can run on microcontrollers, then certainly [Go](https://golang.org/) should be able to run on even lower level micros.
Some code has been copied from the LLVM project and is therefore licensed under [a variant of the Apache 2.0 license](http://releases.llvm.org/11.0.0/LICENSE.TXT). This has been clearly indicated in the header of these files.
Some code has been copied and/or ported from Paul Stoffregen's Teensy libraries and is therefore licensed under PJRC's license. This has been clearly indicated in the header of these files.
