An important point release with some critical fixes and improvements that just could not wait. Thank you very much to our global team of humans who joined together so quickly to get this out for all of us! * **machine** - nrf: fix flash writes when SoftDevice is enabled * **runtime** - runtime: avoid fixed math/rand sequence on RP2040/RP2350 (#5124) - runtime: add calls to initRand() during run() for all schedulers - runtime: call initRand() before initHeap() during initialization - runtime: use rand_hwrng hardwareRand for RP2040/RP2350 (#5135) * **libs** - picolibc: use updated location for git repo

This release has what you need the most right now, which is Go 1.25 support! Of course it has other new features, such as adding multicore support for the RP2350 family of processors as well as for macOS. We've also got fixes, and as always further improvements for `reflect` support and `stdlib` packages. Plus a couple of new boards too! * **general** - all: add Go 1.25 support - net: update to latest tinygo net package - docs: clarify build verification step for macOS users - Add flag to skip Renesas SVD builds * **build** - Makefile: install missing dlmalloc files - flash: add -o flag support to save built binary (Fixes #4937) (#4942) - fix: update version of clang to 17 to accommodate latest Go 1.25 docker base image * **ci** - chore: update all CI builds to test Go 1.25 release - fix: disable test-newest since CircleCI seems unable to download due to rate-limits on Dockerhub - ci: rename some jobs to avoid churn on every Go/LLVM version bump - ci: make the goroutines test less racy - tests: de-flake goroutines test * **compiler** - compiler: implement internal/abi.Escape * **main** - main: show the compiler error (if any) for `tinygo test -c` - chore: correct GOOS=js name in error messages for WASM * **machine** - machine: add international keys - machine: remove some unnecessary "// peripherals:" comments - machine: add I2C pin comments - machine: standardize I2C errors with "i2c:" prefix - machine: make I2C usable in the simulator - fix: add SPI and I2C to teensy 4.1 (#4943) - `rp2`: use the correct channel mask for rp2350 ADC; hold lock during read (#4938) - `rp2`: disable digital input for analog inputs * **runtime** - runtime: ensure time.Sleep(d) sleeps at least d - runtime: stub out weak pointer support - runtime: implement dummy AddCleanup - runtime: enable multi-core scheduler for rp2350 - `internal/task`: use -stack-size flag when starting a new thread - `internal/task`: add SA_RESTART flag to GC interrupts - `internal/task`: a few small correctness fixes - `internal/gclayout`: make gclayout values constants - darwin: add threading support and use it by default * **standard library** - `sync`: implement sync.Swap - `reflect`: implement Method.IsExported * **testing** - testing: stub out testing.B.Loop * **targets** - `stm32`: add support for the STM32L031G6U6 - add metro-rp2350 board definition (#4989) - `rp2040/rp2350`: set the default stack size to 8k for rp2040/rp2350 based boards where this was not already the case

This release includes some very exciting new features, in particular our first multicore support! Initially available on the RP2040 microcontrollers, now TinyGo can use both cores at the same time for true concurrency in hardware. Another very powerful new capability added in this release is USB Mass Storage Device (MSD) support on the RP2040/RP2350, SAMD21, and SAMD51 series of processors. We have also added experimental Boehm garbage collector for WebAssembly to speed up your production code. * **general** - `go.*`: upgrade `golang.org/x/tools` to v0.30.0 - `all`: add support for LLVM 20 * **build** - go back to using MinoruSekine/setup-scoop for Windows CI builds - `flake.*`: upgrade to nixpkgs 25.05, LLVM 20 - `Makefile`: only detect ccache command when needed - `Makefile`: create random filename inside rule - `Makefile`: don't set GOROOT - `Makefile`: call uname at most once - `Makefile`: only read NodeJS version when it is needed * **compiler** - add support for `GODEBUG=gotypesalias=1` - `interp`: fix `copy()` from/to external buffers - add `-nobounds` (similar to `-gcflags=-B`) - `compileopts`: add library version to cached library path - `builder`: build wasi-libc inside TinyGo - `builder`: simplify bdwgc libc dependency - `builder`: don't use precompiled libraries - `compileopts`: enable support for `GOARCH=wasm` in `tinygo test` * **fixes** - `rp2350`: Fix DMA to SPI transmits on RP2350 (#4903) - `microbit v2`: use OpenOCD flash method on microbit v2 when using Nordic Semi SoftDevice - `main`: display all of the current GC options for the `-gc` flag - Remove duplicated error handling - `sync`: fix `TestMutexConcurrent` test - fix race condition in `testdata/goroutines.go` - fix build warnings on Windows ARM * **machine** - `usb`: add USB mass storage class support - implement usb receive message throttling - declare usb endpoints per-platform - `samd21`: implement watchdog - `samd51`: write to flash memory in 512 byte long chunks - `samd21`: write to flash memory in 64 byte long chunks - don't inline RTT `WriteByte` everywhere - `rp2`: unexport machine-specific errors - `rp2`: discount scheduling delays in I2C timeouts (#4876) - use pointer receiver in simulated PWM peripherals - add simulated PWM/timer peripherals - `rp2`: expose usb endpoint stall handling - `arm`: clear pending interrupts before enabling them - `rp2`: merge common usb code (#4856) * **main** - add "cores" and "threads" schedulers to help text - add `StartPos` and `EndPos` to `-json` build output - change `-json` flag to match upstream Go * **runtime** - don't lock the print output inside interrupts - don't try to interrupt other cores before they are started - implement `NumCPU` for the multicore scheduler - add support for multicore scheduler - refactor obtaining the system stack - `interrupt`: add `Checkpoint` type - add `exportedFuncPtr` - avoid an allocation in `(*time.Timer).Reset` - stub runtime signal functions for `os/signal` on wasip1 - move `timeUnit` to a single place - implement `NumCPU` for `-scheduler=threads` - move `mainExited` boolean - `internal/task`: rename `tinygo_pause` to `tinygo_task_exit` - map every goroutine to a new OS thread - refactor `timerQueue` - make conservative and precise GC MT-safe - `internal/task`: implement atomic primitives for preemptive scheduling - Use diskutil on macOS to extract volume name and path for FAT mounts #4928 * **standard library** - `net`: update submodule to latest commits - `runtime/debug`: add GC related stubs - `metrics`: flesh out some of the metric types - `reflect`: Chan related stubs - `os`: handle relative and abs paths in `Executable()` - `os`: add `os.Executable()` for Darwin - `sync`: implement `RWMutex` using futexes - `reflect`: Add `SliceOf`, `ArrayOf`, `StructOf`, `MapOf`, `FuncOf` * **targets** - `rp2040`: add multicore support - `riscv32`: use `gdb` binary as a fallback - add target for Microbit v2 with SoftDevice S140 support for both peripheral and central - `windows`: use MSVCRT.DLL instead of UCRT on i386 - `windows`: add windows/386 support - `arm64`: remove unnecessary `.section` directive - `riscv-qemu`: actually sleep in `time.Sleep()` - `riscv`: define CSR constants and use them where possible - `darwin`: support Boehm GC (and use by default) - `windows`: add support for the Boehm-Demers-Weiser GC - `windows`: fix wrong register for first parameter * **wasm** - add Boehm GC support - refactor/modify stub signal handling - don't block `//go:wasmexport` because of running goroutines - use `int64` instead of `float64` for the `timeUnit` * **boards** - Add board support for BigTreeTech SKR Pico (#4842)

* **general** - add initial Go 1.24 support - add support for LLVM 19 - update license for 2025 - make small corrections for README regarding wasm - use GOOS and GOARCH for building wasm simulated boards - only infer target for wasm when GOOS and GOARCH are set correctly, not just based on file extension - add test-corpus-wasip2 - use older image for cross-compiling builds - update Linux builds to run on ubuntu-latest since 20.04 is being retired - ensure build output directory is created - add NoSandbox flag to chrome headless that is run during WASM tests, since this is now required for Ubuntu 23+ and we are using Ubuntu 24+ when running Github Actions - update wasmtime used for CI to 29.0.1 to fix issue with install during CI tests - update to use `Get-CimInstance` as `wmic` is being deprecated on WIndows - remove unnecessary executable permissions - `goenv`: update to new v0.36.0 development version * **compiler** - `builder`: fix parsing of external ld.lld error messages - `cgo`: mangle identifier names - `interp`: correctly mark functions as modifying memory - add buildmode=wasi-legacy to support existing base of users who expected the older behavior for wasi modules to not return an exit code as if they were reactors * **standard library** - `crypto/tls`: add Dialer.DialContext() to fix websocket client - `crypto/tls`: add VersionTLS constants and VersionName(version uint16) method that turns it into a string, copied from big go - `internal/syscall/unix`: use our own version of this package - `machine`: replace hard-coded cpu frequencies on rp2xxx - `machine`: bump rp2350 CPUFrequency to 150 MHz - `machine`: compute rp2 clock dividers from crystal and target frequency - `machine`: remove bytes package dependency in flash code - `machine/usb/descriptor`: avoid bytes package - `net`: update to latest submodule with httptest subpackage and ResolveIPAddress implementation - `os`: add File.Chdir support - `os`: implement stub Chdir for non-OS systems - `os/file`: add file.Chmod - `reflect`: implement Value.Equal - `runtime`: add FIPS helper functions - `runtime`: manually initialize xorshift state - `sync`: move Mutex to internal/task - `syscall`: add wasip1 RandomGet - `testing`: add Chdir - `wasip2`: add stubs to get internal/syscall/unix to work * **fixes** - correctly handle calls for GetRNG() when being made from nrf devices with SoftDevice enabled - fix stm32f103 ADC - `wasm`: correctly handle id lookup for finalizeRef call - `wasm`: avoid total failure on wasm finalizer call - `wasm`: convert offset as signed int into unsigned int in syscall/js.stringVal in wasm_exec.js * **targets** - rp2350: add pll generalized solution; fix ADC handles; pwm period fix - rp2350: extending support to include the rp2350b - rp2350: cleanup: unexport internal USB and clock package variable, consts and types - nrf: make ADC resolution changeable - turn on GC for TKey1 device, since it does in fact work - match Pico2 stack size to Pico * **boards** - add support for Pimoroni Pico Plus2 - add target for pico2-w board - add comboat_fw tag for elecrow W5 boards with Combo-AT Wifi firmware - add support for Elecrow Pico rp2350 W5 boards - add support for Elecrow Pico rp2040 W5 boards - add support for NRF51 HW-651 - add support for esp32c3-supermini - add support for waveshare-rp2040-tiny * **examples** - add naive debouncing for pininterrupt example

This is our last release of the year, and we've got plenty of presents for all of us tiny gophers! We are happy to show improved error messages, and also a new HTML size report to help figure out what exactly is ending up in that binary. There are several CGo improvements, such as support for function-like macros. We've got a whole slew of improvements for reflection and runtime support, alongside several fixes and improvements for WASM. New hardware! Support for the new RP2350 microcontroller, with the Raspberry Pi Pico2 and Pimoroni Tiny2350 boards. And we are excited to bring our first software RISC-V running on FPGA to TinyGo with the newly added Tillitis TKey hardware device. * **general** - update cmsis-svd library - use default UART settings in the echo example - `goenv`: also show git hash with custom build of TinyGo - `goenv`: support parsing development versions of Go - `main`: parse extldflags early so we can report the error message * **compiler** - `builder`: whitelist temporary directory env var for Clang invocation to fix Windows bug - `builder`: fix cache paths in `-size=full` output - `builder`: work around incorrectly escaped DWARF paths on Windows (Clang bug) - `builder`: fix wasi-libc path names on Windows with `-size=full` - `builder`: write HTML size report - `cgo`: support C identifiers only referred to from within macros - `cgo`: support function-like macros - `cgo`: support errno value as second return parameter - `cgo`: add support for `#cgo noescape` lines - `compiler`: fix bug in interrupt lowering - `compiler`: allow panic directly in `defer` - `compiler`: fix wasmimport -> wasmexport in error message - `compiler`: support `//go:noescape` pragma - `compiler`: report error instead of crashing when instantiating a generic function without body - `interp`: align created globals * **standard library** - `machine`: modify i2s interface/implementation to better match specification - `os`: implement `StartProcess` - `reflect`: add `Value.Clear` - `reflect`: add interface support to `NumMethods` - `reflect`: fix `AssignableTo` for named + non-named types - `reflect`: implement `CanConvert` - `reflect`: handle more cases in `Convert` - `reflect`: fix Copy of non-pointer array with size > 64bits - `runtime`: don't call sleepTicks with a negative duration - `runtime`: optimize GC scanning (findHead) - `runtime`: move constants into shared package - `runtime`: add `runtime.fcntl` function for internal/syscall/unix - `runtime`: heapptr only needs to be initialized once - `runtime`: refactor scheduler (this fixes a few bugs with `-scheduler=none`) - `runtime`: rewrite channel implementation to be smaller and more flexible - `runtime`: use `SA_RESTART` when registering a signal for os/signal - `runtime`: implement race-free signals using futexes - `runtime`: run deferred functions in `Goexit` - `runtime`: remove `Cond` which seems to be unused - `runtime`: properly handle unix read on directory - `runtime/trace`: stub all public methods - `sync`: don't use volatile in `Mutex` - `sync`: implement `WaitGroup` using a (pseudo)futex - `sync`: make `Cond` parallelism-safe - `syscall`: use wasi-libc tables for wasm/js target * **targets** - `mips`: fix a bug when scanning the stack - `nintendoswitch`: get this target to compile again - `rp2350`: add support for the new RP2350 - `rp2040/rp2350` : make I2C implementation shared for rp2040/rp2350 - `rp2040/rp2350` : make SPI implementation shared for rp2040/rp2350 - `rp2040/rp2350` : make RNG implementation shared for rp2040/rp2350 - `wasm`: revise and simplify wasmtime argument handling - `wasm`: support `//go:wasmexport` functions after a call to `time.Sleep` - `wasm`: correctly return from run() in wasm_exec.js - `wasm`: call process.exit() when go.run() returns - `windows`: don't return, exit via exit(0) instead to flush stdout buffer * **boards** - add support for the Tillitis TKey - add support for the Raspberry Pi Pico2 (based on the RP2040) - add support for Pimoroni Tiny2350

This release adds support for [`//go:wasmexport`](https://github.com/golang/go/issues/65199) that is a standardized way to export WebAssembly functions to the host, improves garbage collection performance (especially on wasm), adds big-endian MIPS support (`GOOS=mips`), and adds two new boards! It also contains a number of smaller improvements and bug fixes. * **general** - fix `GOOS=wasip1` for `tinygo test` - add `-C DIR` flag - add initial documentation for project governance - add `-ldflags='-extldflags=...'` support - improve usage message with `tinygo help` and when passing invalid parameters * **compiler** - `builder`: remove environment variables when invoking Clang, to avoid the environment changing the behavior - `builder`: check for the Go toolchain version used to compile TinyGo - `cgo`: add `C.CBytes` implementation - `compiler`: fix passing weirdly-padded structs as parameters to new goroutines - `compiler`: support pragmas on generic functions - `compiler`: do not let the slice buffer escape when casting a `[]byte` or `[]rune` to a string, to help escape analysis - `compiler`: conform to the latest iteration of the wasm types proposal - `loader`: don't panic when main package is not named 'main' - `loader`: make sure we always return type checker errors even without type errors - `transform`: optimize range over `[]byte(string)` * **standard library** - `crypto/x509`: add package stub to build crypto/x509 on macOS - `machine/usb/adc/midi`: fix `PitchBend` - `os`: add `Truncate` stub for baremetal - `os`: add stubs for `os.File` deadlines - `os`: add internal `net.newUnixFile` for the net package - `runtime`: stub runtime_{Before,After}Exec for linkage - `runtime`: randomize map accesses - `runtime`: support `maps.Clone` - `runtime`: add more fields to `MemStats` - `runtime`: implement newcoro, coroswitch to support package iter - `runtime`: disallow defer in interrupts - `runtime`: add support for os/signal on Linux and MacOS - `runtime`: add gc layout info for some basic types to help the precise GC - `runtime`: bump GC mark stack size to avoid excessive heap rescans * **targets** - `darwin`: use Go standard library syscall package instead of a custom one - `fe310`: support GPIO `PinInput` - `mips`: fix compiler crash with GOMIPS=softfloat and defer - `mips`: add big-endian (GOARCH=mips) support - `mips`: use MIPS32 (instead of MIPS32R2) as the instruction set for wider compatibility - `wasi`: add relative and absolute --dir options to wasmtime args - `wasip2`: add wasmtime -S args to support network interfaces - `wasm`: add `//go:wasmexport` support (for all WebAssembly targets) - `wasm`: use precise instead of conservative GC for WebAssembly (including WASI) - `wasm-unknown`: add bulk memory flags since basically every runtime has it now * **boards** - add [RAKwireless RAK4631](https://store.rakwireless.com/products/rak4631-lpwan-node) - add [WaveShare ESP-C3-32S-Kit](https://www.waveshare.com/wiki/ESP-C3-32S-Kit)

This is an important release. No new boards, but we make up for that by adding a bunch of other big stuff! Some of the highlights: * Go 1.23 support (including the new [range-over-func](https://go.dev/wiki/RangefuncExperiment) language feature) * WASI preview 2 support * MIPS little endian support (big endian support is still experimental), so you can use `GOARCH=mipsle` * softfloat support for ARM and MIPS * improved error messages For a full list of changes, see the list below. * **general** - use latest version of x/tools - add chromeos 9p support for flashing - sort compiler error messages by source position in a package - don't include prebuilt libraries in the release to simplify packaging and reduce the release tarball size - show runtime panic addresses for `tinygo run` - support Go 1.23 (including all new language features) - `test`: support GOOS/GOARCH pairs in the `-target` flag - `test`: remove message after test binary built * **compiler** - remove unused registers for x86_64 linux syscalls - remove old atomics workaround for AVR (not necessary in modern LLVM versions) - support `golang.org/x/sys/unix` syscalls - `builder`: remove workaround for generics race condition - `builder`: add package ID to compiler and optimization error messages - `builder`: show better error messages for some common linker errors - `cgo`: support preprocessor macros passed on the command line - `cgo`: use absolute paths for error messages - `cgo`: add support for printf - `loader`: handle `go list` errors inside TinyGo (for better error messages) - `transform`: fix incorrect alignment of heap-to-stack transform - `transform`: use thinlto-pre-link passes (instead of the full pipeline) to speed up compilation speed slightly * **standard library** - `crypto/tls`: add CipherSuiteName and some extra fields to ConnectionState - `internal/abi`: implement initial version of this package - `machine`: use new `internal/binary` package - `machine`: rewrite Reply() to fix sending long replies in I2C Target Mode - `machine/usb/descriptor`: Reset joystick physical - `machine/usb/descriptor`: Drop second joystick hat - `machine/usb/descriptor`: Add more HID... functions - `machine/usb/descriptor`: Fix encoding of values - `machine/usb/hid/joystick`: Allow more hat switches - `os`: add `Chown`, `Truncate` - `os/user`: use stdlib version of this package - `reflect`: return correct name for the `unsafe.Pointer` type - `reflect`: implement `Type.Overflow*` functions - `runtime`: implement dummy `getAuxv` to satisfy golang.org/x/sys/ - `runtime`: don't zero out new allocations for `-gc=leaking` when they are already zeroed - `runtime`: simplify slice growing/appending code - `runtime`: print a message when a fatal signal like SIGSEGV happens - `runtime/debug`: add `GoVersion` to `debug.BuildInfo` - `sync`: add `Map.Clear()` - `sync/atomic`: add And* and Or* compiler intrinsics needed for Go 1.23 - `syscall`: add `Fork` and `Execve` - `syscall`: add all MacOS errno values - `testing`: stub out `T.Deadline` - `unique`: implement custom (naive) version of the unique package * **targets** - `arm`: support `GOARM=*,softfloat` (softfloat support for ARM v5, v6, and v7) - `mips`: add linux/mipsle (and experimental linux/mips) support - `mips`: add `GOMIPS=softfloat` support - `wasip2`: add WASI preview 2 support - `wasm/js`: add `node:` prefix in `require()` call of wasm_exec.js - `wasm-unknown`: make sure the `os` package can be imported - `wasm-unknown`: remove import-memory flag

This release has lots of features and fixes that you need. From support for the new LLVM 18, to a patched version of the `go/ssa` package with a fix for the race condition that annoys anyone who maintains a CI build using TinyGo. Of course, no TinyGo release would be complete without new hardware supported, such as the Pimoroni Badger2040-W. And more WASM features too! * **general** - fix wasi-libc include headers on Nix - apply OpenOCD commands after target configuration - fix a minor race condition when determining the build tags - support UF2 drives with a space in their name on Linux - add LLVM 18 support - drop support for Go 1.18 to be able to stay up to date * **compiler** - move `-panic=trap` support to the compiler/runtime - fix symbol table index for WebAssembly archives - fix ed25519 build errors by adjusting the alias names - add aliases to generic AES functions - fix race condition by temporarily applying a proposed patch - `builder`: keep un-wasm-opt'd .wasm if -work was passed - `builder`: make sure wasm-opt command line is printed if asked - `cgo`: implement shift operations in preprocessor macros - `interp`: checking for methodset existance * **standard library** - `machine`: add `__tinygo_spi_tx` function to simulator - `machine`: fix simulator I2C support - `machine`: add GetRNG support to simulator - `machine`: add `TxFifoFreeLevel` for CAN - `os`: add `Link` - `os`: add `FindProcess` for posix - `os`: add `Process.Release` for unix - `os`: add `SetReadDeadline` stub - `os`, `os/signal`: add signal stubs - `os/user`: add stubs for `Lookup{,Group}` and `Group` - `reflect`: use int in `StringHeader` and `SliceHeader` on non-AVR platforms - `reflect`: fix `NumMethods` for Interface type - `runtime`: skip negative sleep durations in sleepTicks * **targets** - `esp32`: add I2C support - `rp2040`: move UART0 and UART1 to common file - `rp2040`: make all RP2040 boards available for simulation - `rp2040`: fix timeUnit type - `stm32`: add i2c `Frequency` and `SetBaudRate` function for chips that were missing implementation - `wasm-unknown`: add math and memory builtins that LLVM needs - `wasip1`: replace existing `-target=wasi` support with wasip1 as supported in Go 1.21+ * **boards** - `adafruit-esp32-feather-v2`: add the Adafruit ESP32 Feather V2 - `badger2040-w`: add support for the Badger2040 W - `feather-nrf52840-sense`: fix lack of LXFO - `m5paper`: add support for the M5 Paper - `mksnanov3`: limit programming speed to 1800 kHz - `nucleol476rg`: add stm32 nucleol476rg support - `pico-w`: add the Pico W (which is near-idential to the pico target) - `thingplus-rp2040`, `waveshare-rp2040-zero`: add WS2812 definition - `pca10059-s140v7`: add this variant to the PCA10059 board