Replace binary blobs with inline assembly

Author: Disasm

.github/workflows/ci.yaml

@@ -28,13 +28,9 @@ jobs:
           override: true
       - name: Install all Rust targets for ${{ matrix.rust }}
         run: rustup target install --toolchain=${{ matrix.rust }} riscv32imac-unknown-none-elf riscv64imac-unknown-none-elf riscv64gc-unknown-none-elf
-      - name: Install riscv gcc
-        run: sudo apt-get update && sudo apt-get install -y gcc-riscv64-unknown-elf
       - name: Run CI script for riscv32imac-unknown-none-elf under ${{ matrix.rust }}
         run: cargo check --target riscv32imac-unknown-none-elf
       - name: Run CI script for riscv64imac-unknown-none-elf under ${{ matrix.rust }}
         run: cargo check --target riscv64imac-unknown-none-elf
       - name: Run CI script for riscv64gc-unknown-none-elf under ${{ matrix.rust }}
         run: cargo check --target riscv64gc-unknown-none-elf
-      - name: Check blobs
-        run: ./check-blobs.sh

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Changed
+
+- Use inline assembly instead of binary blobs
+
 ## [v0.9.0] - 2022-07-01
 
 ### Added

Cargo.toml

@@ -8,6 +8,7 @@ categories = ["embedded", "no-std"]
 description = "Minimal runtime / startup for RISC-V CPU's"
 keywords = ["riscv", "runtime", "startup"]
 license = "ISC"
+links = "riscv-rt" # prevent multiple versions of this crate to be linked together
 edition = "2018"
 
 [dependencies]
@@ -17,6 +18,3 @@ riscv-rt-macros = { path = "macros", version = "0.2.0" }
 
 [dev-dependencies]
 panic-halt = "0.2.0"
-
-[build-dependencies]
-riscv-target = "0.1.2"

asm.S

@@ -1,24 +1,17 @@
 // NOTE: Adapted from cortex-m/build.rs
-extern crate riscv_target;
-
-use riscv_target::Target;
 use std::env;
 use std::fs;
 use std::path::PathBuf;
 
 fn main() {
     let target = env::var("TARGET").unwrap();
     let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let name = env::var("CARGO_PKG_NAME").unwrap();
 
     if target.starts_with("riscv") {
-        let mut target = Target::from_target_str(&target);
-        target.retain_extensions("imfdc");
-        let archive = format!("bin/{}.a", target.to_string());
-
-        fs::copy(&archive, out_dir.join(format!("lib{}.a", name))).unwrap();
-        println!("cargo:rerun-if-changed={}", archive);
-        println!("cargo:rustc-link-lib=static={}", name);
+        let extensions = &target.split('-').next().unwrap()[7..];
+        if extensions.contains('m') || extensions.contains('g') {
+            println!("cargo:rustc-cfg=riscv_mul");
+        }
     }
 
     // Put the linker script somewhere the linker can find it