> ## Documentation Index
> Fetch the complete documentation index at: https://docs.optimism.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported Targets

Kona seeks to support all FPVM targets that LLVM and `rustc` can offer introductory support for. Below is a matrix of features that Kona offers
for each FPVM target:

| Target                 | Build Pipeline | IO | malloc |
| ---------------------- | -------------- | -- | ------ |
| `cannon` & `cannon-rs` | ✅              | ✅  | ✅      |
| `asterisc`             | ✅              | ✅  | ✅      |

If there is a feature that you would like to see supported, please [open an issue][new-issue] or [consider contributing][contributing]!

## Asterisc (RISC-V)

Asterisc is based off of the `rv64gc` target architecture, which defines the following extensions:

* `RV32I` support - 32 bit base instruction set
  * `FENCE`, `ECALL`, `EBREAK` are hardwired to implement a minimal subset of systemcalls of the linux kernel
    * Work in progress. All syscalls used by the Golang `risc64` runtime.
* `RV64I` support
* `RV32M`+`RV64M`: Multiplication support
* `RV32A`+`RV64A`: Atomics support
* `RV{32,64}{D,F,Q}`: no-op: No floating points support (since no IEEE754 determinism with rounding modes etc., nor worth the complexity)
* `Zifencei`: `FENCE.I` no-op: No need for `FENCE.I`
* `Zicsr`: no-op: some support for Control-and-status registers may come later though.
* `Ztso`: no-op: no need for Total Store Ordering
* other: revert with error code on unrecognized instructions

`asterisc` supports a plethora of syscalls, documented [in the repository][asterisc-syscalls]. `kona` offers an interface for
programs to directly invoke a select few syscalls:

1. `EXIT` - Terminate the process with the provided exit code.
2. `WRITE` - Write the passed buffer to the passed file descriptor.
3. `READ` - Read the specified number of bytes from the passed file descriptor.

[asterisc-syscalls]: https://github.com/ethereum-optimism/asterisc/blob/master/docs/golang.md#linux-syscalls-used-by-go

## Cannon (MIPS64r2)

Cannon is based off of the `mips64r2` target architecture, specified in [MIPS® Architecture For Programmers Volume II-A: The MIPS64® Instruction Set Reference Manual](https://s3-eu-west-1.amazonaws.com/downloads-mips/documents/MIPS_Architecture_MIPS64_InstructionSet_%20AFP_P_MD00087_06.05.pdf)

### Syscalls

Syscalls supported by `cannon` can be found within the `cannon` specification [here][cannon-syscalls].

[cannon-syscalls]: https://specs.optimism.io/fault-proof/cannon-fault-proof-vm.html#syscalls

[op-stack]: https://github.com/ethereum-optimism/optimism

[op-program]: https://github.com/ethereum-optimism/optimism/tree/develop/op-program

[cannon]: https://github.com/ethereum-optimism/optimism/tree/develop/cannon

[cannon-rs]: https://github.com/op-rs/cannon-rs

[asterisc]: https://github.com/ethereum-optimism/asterisc

[fp-specs]: https://specs.optimism.io/experimental/fault-proof/index.html

[fpp-specs]: https://specs.optimism.io/experimental/fault-proof/index.html#fault-proof-program

[preimage-specs]: https://specs.optimism.io/experimental/fault-proof/index.html#pre-image-oracle

[cannon-specs]: https://specs.optimism.io/experimental/fault-proof/cannon-fault-proof-vm.html#cannon-fault-proof-virtual-machine

[l2-output-root]: https://specs.optimism.io/protocol/proposals.html#l2-output-commitment-construction

[op-succinct]: https://github.com/succinctlabs/op-succinct

[revm]: https://github.com/bluealloy/revm

[kona]: https://github.com/ethereum-optimism/optimism/tree/develop/rust/kona

[issues]: https://github.com/ethereum-optimism/optimism/issues

[new-issue]: https://github.com/ethereum-optimism/optimism/issues/new

[contributing]: https://github.com/ethereum-optimism/optimism/tree/develop/rust/kona/CONTRIBUTING.md

[op-labs]: https://github.com/ethereum-optimism

[bad-boi-labs]: https://github.com/BadBoiLabs