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)