| commit | 28913fdd14162f687c667b4e754ee8f07737b7ea | [log] [tgz] |
|---|---|---|
| author | bors[bot] <26634292+bors[bot]@users.noreply.github.com> | Tue Feb 09 23:10:32 2021 +0000 |
| committer | GitHub <noreply@github.com> | Tue Feb 09 23:10:32 2021 +0000 |
| tree | 9dedcbf92098e6f251fd8c52955cbb466b0fb240 | |
| parent | eff585190aca2ba62872eae3623667fda95f4d36 [diff] | |
| parent | 9b7a489f451a54fab6f6534a3b4a48c532726dcb [diff] |
Merge #272 272: Add the RISC-V entry point assembly to libtock_runtime r=hudson-ayers a=jrvanwhy To support the entry point assembly, I rewrote the linker script ([link to the new version](https://github.com/jrvanwhy/libtock-rs/blob/riscv-asm/core/runtime/layout_generic.ld) in case you don't want to see the diff). The rust toolchain is unable to compile raw assembly files on its own. I don't want a separate toolchain to be a build requirement of `libtock-rs`, so instead I committed the compiled library into the repository. To keep the compiled library and source code in sync, I added an actions workflow that verifies the compiled library matches the provided sources. There is one part of this PR I am unhappy with. I have to manually `strip` local symbols from the compiled library -- i.e., removing the `riscv64-linux-gnu-strip` invocation from `assemble.sh` gives the following: ``` Disassembly of section .start: 00000000 <start>: 0: 00000417 auipc s0,0x0 4: 87aa mv a5,a0 6: 4384 lw s1,0(a5) 8: 00940c63 beq s0,s1,20 <.Lset_brk> c: 4521 li a0,8 e: 4585 li a1,1 10: 4609 li a2,2 12: 4709 li a4,2 14: 00000073 ecall 18: 4501 li a0,0 1a: 4719 li a4,6 1c: 00000073 ecall 00000020 <.Lset_brk>: 20: 4501 li a0,0 22: 43cc lw a1,4(a5) 24: 4715 li a4,5 26: 00000073 ecall 2a: 0087a103 lw sp,8(a5) 2e: 47c8 lw a0,12(a5) 30: c909 beqz a0,42 <.Lzero_bss> 32: 4b8c lw a1,16(a5) 34: 4bd0 lw a2,20(a5) 00000036 <.Ldata_loop_body>: 36: 4194 lw a3,0(a1) 38: c214 sw a3,0(a2) 3a: 1571 addi a0,a0,-4 3c: 0591 addi a1,a1,4 3e: 0611 addi a2,a2,4 40: f97d bnez a0,36 <.Ldata_loop_body> 00000042 <.Lzero_bss>: 42: 4f88 lw a0,24(a5) 44: c519 beqz a0,52 <.Lcall_rust_start> 46: 4fcc lw a1,28(a5) 00000048 <.Lbss_loop_body>: 48: 00058023 sb zero,0(a1) 4c: 157d addi a0,a0,-1 4e: 0585 addi a1,a1,1 50: fd65 bnez a0,48 <.Lbss_loop_body> 00000052 <.Lcall_rust_start>: 52: fafff0ef jal ra,0 <start> ``` I'd appreciate advice on how to prevent `riscv64-linux-gnu-as` from including the local symbols in its output. Co-authored-by: Johnathan Van Why <jrvanwhy@google.com>
Rust userland library for Tock (WIP)
Generally this library was tested with tock Release 1.5. Since then changes have been made that might not work with the Tock release 1.5, but instead target Tock master. For example this library might support newer boards (Apollo3), changed boards (HiFive1 revB) or new drivers (HMAC).
The library works in principle on most boards, but there is currently the showstopper bug #28 that prevents the generation of relocatable code. This means that all applications must be installed at the flash address they are compiled with, which usually means that they must be compiled especially for your board and that there can only be one application written in rust at a time and it must be installed as the first application on the board, unless you want to play games with linker scripts. There are some boards/layout_*.ld files provided that allow to run the examples on common boards. Due to MPU region alignment issues they may not work for applications that use a lot of RAM, in that case you may have to change the SRAM start address to fit your application.
This project is nascent and still under heavy development, but first steps:
Ensure you have rustup installed.
Clone the repository:
git clone --recursive https://github.com/tock/libtock-rs cd libtock-rs
Install the dependencies:
make setup
Use make to build examples
make nrf52 # Builds all examples for the nrf52 platform
make opentitan # Builds all examples for the OpenTitan platform
make opentitan FEATURES=alloc # Builds all examples for the OpenTitan platform, with alloc feature enabled
make flash-hail EXAMPLE=blink # Flash the example 'blink' program to the hail platform
For an unknown platform, you may have to create your own memory layout definition. Place the layout definition file at boards/layout_<platform>.ld and do not forget to enhance the tockloader_flags dispatching section in tools/flash.sh. You are welcome to create a PR, s.t. the number of supported platforms grows.
The easiest way to start using libtock-rs is adding an example to the examples folder. The boiler plate code you would write is
#![no_std] use libtock::result::TockResult; #[libtock::main] async fn main() -> TockResult<()> { // Your code }
If you want to use heap based allocation you will have to add
extern crate alloc;
to the preamble and store your example in the examples-alloc folder.
To build the examples for your board you can use
make <platform> [FEATURES=alloc]
An example can be flashed to your board after the build process by running:
make flash-<platform> EXAMPLE=<example>
This script does the following steps for you:
libtock-rs is licensed under either of
at your option.
Submodules have their own licenses.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
The contribution guidelines can be found here: contribution guidelines