Adding CI for building the kernel and checking Clippy lints

.github/workflows/build.yml

@@ -0,0 +1,42 @@
+name: Kernel CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: rust-src, clippy
+
+      # - name: Get just
+      #   uses: taiki-e/install-action@just
+
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: ${{ runner.os }}-cargo-
+
+      - name: Build
+        run: cargo build --verbose
+
+      # - name: Test
+      #   run: cargo test --verbose
+
+      - name: Clippy
+        run: cargo clippy --all-features -- -D warnings

src/allocator/tiered.rs

@@ -32,7 +32,7 @@ impl BuddySystem {
     /// # Safety
     /// This is safe as long as the `addr` is valid
     pub unsafe fn init(base: usize) -> Result<Self, AllocatorError> {
-        if base % PAGE_SIZE != 0 {
+        if base.is_multiple_of(PAGE_SIZE) {
             return Err(AllocatorError::AddrNotAligned {
                 addr: base,
                 align: PAGE_SIZE,

src/kinit.rs

@@ -14,7 +14,7 @@ pub fn pre_kinit(balloc: &mut BitMapAlloc, fdt: fdt::Fdt) {
         let addr = balloc.alloc(STACK_PAGES);
         // the address we are returned is at the top of the allocated space, we need to go lower
         let stack_bottom = addr + STACK_SIZE;
-        sbi::hsm::start(id, _start as usize, stack_bottom);
+        sbi::hsm::start(id, _start as *const () as usize, stack_bottom);
     }
 }
 

src/vmem.rs

@@ -78,7 +78,7 @@ impl PTEntry {
     }
 }
 
-pub fn init(balloc: &mut BitMapAlloc) -> Mapper {
+pub fn init(balloc: &mut BitMapAlloc) -> Mapper<'_> {
     let tbl_addr = balloc.alloc(1);
     PAGE_TABLE.store(tbl_addr, Ordering::Relaxed);
 
@@ -95,7 +95,7 @@ fn map(
     perms: Perms,
     pages: usize,
 ) -> Result<(), MapError> {
-    assert!((vaddr & 4096) % 4096 == 0);
+    assert!((vaddr & 4096).is_multiple_of(4096));
     assert!(pages > 0);
 
     for i in 0..pages {