Stream: git-wasmtime

Topic: wasmtime / issue #1173 Cranelift: arm32 support

Wasmtime GitHub notifications bot (Dec 20 2024 at 19:31):

alexcrichton edited issue #1173:

• What is the feature or code improvement you would like to do in Cranelift?
  I would like to add ARM support by implementing ARM (not Thumb) encodings/recipes and abi. I am especially interested in armv7 little endian support.

• What is the value of adding this in Cranelift?
  Emit code that could run on ARM architecture.

• Do you have an implementation plan, and/or ideas for data structures or
  algorithms to use?
  At first i want to add basic integer operations followed by floating point instructions. I thought about implementing the latter using VFP rather than the NEON extension (As far as I know NEON does not support double precision). As for calling convention, I would like to implement AAPCS.
  I already have some code that i hope to push after necessary modifications.

• Have you considered alternative implementations? If so, how are they better
  or worse than your proposal?
  No, but I am open to suggestions.

Wasmtime GitHub notifications bot (Dec 20 2024 at 19:31):

alexcrichton removed the wasmtime:platform-support label from Issue #1173.

Wasmtime GitHub notifications bot (Mar 28 2026 at 00:05):

mytechnotalent commented on issue #1173:

@alexcrichton Just wanted to drop a real-world validation of your recent work on Pulley for 32-bit ARM. I recently got the Pulley interpreter running completely bare-metal on an RP2350 (Cortex-M33) using #![no_std] and the Component Model.

Implementation details:

• Target: thumbv8m.main-none-eabihf (Raspberry Pi Pico 2)
• Memory: 256 KiB heap mapped via embedded-alloc
• Execution: AOT-compiling the guest to .cwasm on the host, and interpreting on the MCU.
• Hardware Abstraction: Using typed WIT interfaces (embedded:platform/gpio) generated by wit-bindgen to map directly to the Pico's pins, avoiding raw env imports or C-bindings entirely.

The repo and architecture diagram are here if it's a useful reference for anyone else pushing Wasmtime into Cortex-M environments: https://github.com/mytechnotalent/embedded-wasm-blinky

Thanks for pushing the Pulley architecture forward—it makes this kind of bare-metal Wasm actually viable.

Wasmtime GitHub notifications bot (Mar 30 2026 at 13:48):

alexcrichton commented on issue #1173:

That's awesome, and thanks for letting us know it's working well for you too! If you spot anything that needs improvement don't hesitate to file an issue

Wasmtime GitHub notifications bot (Mar 30 2026 at 13:53):

mytechnotalent commented on issue #1173:

Will do @alexcrichton and thank you for the kind words! I will be building out a large series of drivers and will be testing them and if I see any issues, I will touch base as I am excited to help expand Wasm into the Embedded community!

Last updated: Apr 13 2026 at 00:25 UTC