* ci: build the compiler image on a prebuilt LLVM image The Docker workflow built LLVM as the first stages of the compiler image. The only thing that prevented a rebuild was the BuildKit registry layer cache. A layer cache is a best-effort optimisation, so CI sometimes built LLVM again although llvm-version.txt did not change. Move the LLVM stages to Dockerfile.llvm and make the compiler image start from that image through an LLVM_IMAGE build argument. The compiler build now holds no LLVM build step, so it cannot build LLVM again. Tag the LLVM image with the LLVM revision and a hash of the files that set the content of the image: llvm-version.txt, Dockerfile.llvm, GNUmakefile, and the files in make/. tools/llvm-image-tag.sh prints the tag, and CI and developers use the same script. The workflow builds and pushes the LLVM image only when the registry does not hold that tag. Remove the object files and the git history from the LLVM image in the same layer as the build. The CI caches already link against that subset, see .github/actions/setup-llvm/action.yml. Delete llvm.yml. It made an image that nothing used, and it needed a push to a special branch. The Docker workflow now does the same work when it is necessary, and the force-llvm input of the manual trigger makes the image again. The LLVM image goes to GHCR only, because only CI uses it. The compiler image continues to go to Docker Hub and GHCR. * ci: remove the LLVM git history in the layer that makes it The removal was in the tinygo-llvm-build stage. This stage is below the layer that makes the shallow clone. A later layer only hides files from a parent layer. Thus the pack files stayed in the published image. * ci: link the LLVM image to the repository The label puts the package in the repository package list, so the package settings are easy to find. BUILDING.md now tells you to build LLVM locally if you are not able to pull the image.
TinyGo - Go compiler for small places
TinyGo is a Go compiler intended for use in small places such as microcontrollers, WebAssembly (wasm/wasi), and command-line tools.
It reuses libraries used by the Go language tools alongside LLVM to provide an alternative way to compile programs written in the Go programming language.
Important
You can help TinyGo with a financial contribution using OpenCollective. Please see https://opencollective.com/tinygo for more information. Thank you!
Embedded
Here is an example program that blinks the built-in LED when run directly on any supported board with onboard LED:
package main
import (
"machine"
"time"
)
func main() {
led := machine.LED
led.Configure(machine.PinConfig{Mode: machine.PinOutput})
for {
led.Low()
time.Sleep(time.Millisecond * 1000)
led.High()
time.Sleep(time.Millisecond * 1000)
}
}
The above program can be compiled and run without modification on an Arduino Uno, an Adafruit Circuit Playground Express, a Seeed Studio XIAO-ESP32S3 or any of the many 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 flash -target arduino-uno examples/blinky1
WebAssembly
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, Fermyon Spin, wazero and many other WebAssembly runtimes.
Here is a small TinyGo program for use by a WASI host application:
package main
//go:wasmexport add
func add(x, y uint32) uint32 {
return x + y
}
This compiles the above TinyGo program for use on any WASI Preview 1 runtime:
tinygo build -buildmode=c-shared -o add.wasm -target=wasip1 add.go
You can also use the same syntax as Go 1.24+:
GOOS=wasip1 GOARCH=wasm tinygo build -buildmode=c-shared -o add.wasm add.go
Installation
See the getting started instructions for information on how to install TinyGo, as well as how to run the TinyGo compiler using our Docker container.
Supported targets
Embedded
You can compile TinyGo programs for over 150 different microcontroller boards.
For more information, please see https://tinygo.org/docs/reference/microcontrollers/
WebAssembly
TinyGo programs can be compiled for both WASM and WASI targets.
For more information, see https://tinygo.org/docs/guides/webassembly/
Operating Systems
You can also compile programs for Linux, macOS, and Windows targets.
For more information:
Currently supported features:
For a description of currently supported Go language features, please see https://tinygo.org/lang-support/.
Documentation
Documentation is located on our web site at https://tinygo.org/.
You can find the web site code at https://github.com/tinygo-org/tinygo-site.
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
Contributing
Your contributions are welcome!
Please take a look at our Contributing page on our web site for details.
Project Scope
Goals:
- 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 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 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 can run on microcontrollers, then certainly Go should be able to run on even lower level micros.
License
This project is licensed under the BSD 3-clause license, just like the Go project itself.
Some code has been copied from the LLVM project and is therefore licensed under a variant of the Apache 2.0 license. 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.