Merge #113

113: Make bootsector a staticlib r=rybot666 a=phil-opp

Makes the bootsector self-contained by making it a staticlib. This ensures that we don't accidentally use functions from stage_2.

The `stage_2` crate is now the main executable, which links the bootsector through a build script.


Co-authored-by: Philipp Oppermann <dev@phil-opp.com>

Author: bors[bot]

.cargo/config

@@ -1,3 +1,2 @@
-[build]
-target = "x86_64-real_mode.json"
-rustflags = ["-C", "link-arg=-Tlinker.ld"]
+[alias]
+xbuild = "build -Zbuild-std=core"

.github/workflows/build.yml

@@ -41,20 +41,15 @@ jobs:
 
     - name: "Install Rustup Components"
       run: rustup component add rust-src llvm-tools-preview
-    - name: "Install cargo-xbuild"
-      run: cargo install cargo-xbuild --debug
     - name: "Install cargo-binutils"
       run: cargo install cargo-binutils --version 0.1.7 --debug
 
-    - run: cargo xbuild
-      working-directory: test-kernel
-      name: 'Build Test Kernel'
-
     - name: 'Build Bootloader'
       run: cargo xbuild --release
+      working-directory: src/stage_2
 
     - name: 'Convert Bootloader ELF to Binary'
-      run: cargo objcopy -- -I elf64-i386 -O binary --binary-architecture=i386:x86-64 target/x86_64-real_mode/release/bootsector target/x86_64-real_mode/release/bootsector.bin
+      run: cargo objcopy -- -I elf64-i386 -O binary --binary-architecture=i386:x86-64 target/x86_64-real_mode/release/stage_2 target/x86_64-real_mode/release/image.bin
 
     #  # install QEMU
     # - name: Install QEMU (Linux)
@@ -108,8 +103,6 @@ jobs:
       if: runner.os == 'macOS'
     - name: "Install Rustup Components"
       run: rustup component add rust-src llvm-tools-preview
-    - name: "Install cargo-xbuild"
-      run: cargo install cargo-xbuild --debug
     - name: 'Build Example Kernel'
       run: cargo xbuild
       working-directory: example-kernel

Cargo.lock

@@ -4,10 +4,15 @@ members = [
   "src/v86",
   "src/bootsector",
   "src/stage_2",
-#  "example-kernel",
-#  "test-kernel",
+  "example-kernel",
+  "test-kernel",
 ]
 
 [profile.release]
 opt-level = "z"
-panic = "abort"
+panic = "abort"
+lto = true
+
+[profile.release.package.bootsector]
+opt-level = "s"
+codegen-units = 1

Cargo.toml

@@ -6,6 +6,9 @@ edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[lib]
+name = "bootsector"
+crate-type = ["staticlib"]
+
 [dependencies]
 shared = { path = "../shared" }
-stage_2 = { path = "../stage_2" }

src/bootsector/Cargo.toml

@@ -1,16 +1,16 @@
-#[inline(never)]
-pub fn println(s: &[u8]) {
+#[no_mangle]
+pub fn real_mode_println(s: &[u8]) {
     print(s);
     print_char(b'\n');
 }
 
 pub fn print(s: &[u8]) {
-	let mut i = 0;
+    let mut i = 0;
 
-	while i < s.len() {
-		print_char(s[i]);
-		i += 1;
-	}
+    while i < s.len() {
+        print_char(s[i]);
+        i += 1;
+    }
 }
 
 #[inline(always)]
@@ -19,4 +19,4 @@ pub fn print_char(c: u8) {
     unsafe {
         llvm_asm!("int 0x10" :: "{ax}"(ax) :: "intel" );
     }
-}
+}

src/bootsector/src/console.rs

@@ -1,18 +1,18 @@
+use super::console::real_mode_println;
 use shared::utils;
-use super::console::println;
 
 #[no_mangle]
-pub extern "C" fn dap_load_failed() -> ! {
-    println(b"[!] DAP Load Failed");
+extern "C" fn dap_load_failed() -> ! {
+    real_mode_println(b"[!] DAP Load Failed");
     loop {
         utils::hlt()
     }
 }
 
 #[no_mangle]
-pub extern "C" fn no_int13h_extensions() -> ! {
-    println(b"[!] No int13h Extensions");
+extern "C" fn no_int13h_extensions() -> ! {
+    real_mode_println(b"[!] No int13h Extensions");
     loop {
         utils::hlt()
     }
-}
+}

src/bootsector/src/errors.rs

@@ -0,0 +1,54 @@
+#![feature(llvm_asm, global_asm)]
+#![no_std]
+#![allow(dead_code)]
+
+mod console;
+mod errors;
+
+use self::console::real_mode_println;
+use core::panic::PanicInfo;
+use shared::{dap, linker_symbol, utils};
+
+extern "C" {
+    fn second_stage();
+}
+global_asm!(include_str!("bootstrap.s"));
+
+#[no_mangle]
+extern "C" fn rust_start(disk_number: u16) -> ! {
+    real_mode_println(b"Stage 1");
+
+    check_int13h_extensions(disk_number);
+
+    let dap = dap::DiskAddressPacket::new(
+        linker_symbol!(_rest_of_bootloader_start) as u16,
+        (linker_symbol!(_rest_of_bootloader_start) - linker_symbol!(_bootloader_start)) as u64,
+        linker_symbol!(_rest_of_bootloader_end) - linker_symbol!(_rest_of_bootloader_start),
+    );
+
+    unsafe { dap.perform_load(disk_number) };
+
+    unsafe { second_stage() };
+
+    loop {
+        utils::hlt();
+    }
+}
+
+fn check_int13h_extensions(disk_number: u16) {
+    unsafe {
+        llvm_asm!("
+			int 0x13
+    		jc no_int13h_extensions
+        " :: "{ah}"(0x41), "{bx}"(0x55aa), "{dl}"(disk_number) :: "intel", "volatile");
+    }
+}
+
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    real_mode_println(b"[Panic]");
+
+    loop {
+        utils::hlt()
+    }
+}

src/bootsector/src/lib.rs

@@ -36,4 +36,4 @@ impl Writer {
             llvm_asm!("int 0x10" :: "{ax}"(ax), "{bx}"(0) :: "intel", "volatile");
         }
     }
-}
+}

src/bootsector/src/main.rs

@@ -4,4 +4,5 @@
 pub mod console;
 pub mod dap;
 pub mod utils;
-#[macro_use] pub mod macros;
+#[macro_use]
+pub mod macros;

src/shared/src/console.rs

@@ -9,4 +9,4 @@ macro_rules! linker_symbol {
 
 		symbol_value
 	}};
-}
+}

src/shared/src/lib.rs

@@ -3,4 +3,4 @@ pub fn hlt() {
     unsafe {
         llvm_asm!("hlt" :::: "intel","volatile");
     }
-}
+}

src/shared/src/macros.rs

@@ -0,0 +1,3 @@
+[build]
+target = "../../x86_64-real_mode.json"
+rustflags = ["-C", "link-arg=-Tlinker.ld"]

src/shared/src/utils.rs

@@ -12,4 +12,7 @@ v86 = { path = "../v86" }
 
 [dependencies.lazy_static]
 version = "1.0"
-features = ["spin_no_std"]
+features = ["spin_no_std"]
+
+[build-dependencies]
+llvm-tools = "0.1.1"

src/stage_2/.cargo/config

@@ -0,0 +1,75 @@
+use llvm_tools::{exe, LlvmTools};
+use std::env;
+use std::path::Path;
+use std::process::Command;
+
+fn main() {
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let llvm_tools = LlvmTools::new().expect("LLVM tools not found");
+    let objcopy = llvm_tools
+        .tool(&exe("llvm-objcopy"))
+        .expect("llvm-objcopy not found");
+
+    build_subproject(
+        Path::new("../bootsector"),
+        &[
+            "_start",
+            "real_mode_println",
+            "no_int13h_extensions",
+            "dap_load_failed",
+        ],
+        "x86_64-real_mode.json",
+        &out_dir,
+        &objcopy,
+    );
+}
+
+fn build_subproject(
+    dir: &Path,
+    global_symbols: &[&str],
+    target: &str,
+    out_dir: &str,
+    objcopy: &Path,
+) {
+    let dir_name = dir.file_name().unwrap().to_str().unwrap();
+    let manifest_path = dir.join("Cargo.toml");
+    let out_path = Path::new(&out_dir);
+    assert!(
+        global_symbols.len() > 0,
+        "must have at least one global symbol"
+    );
+
+    // build
+    let mut cmd = Command::new("cargo");
+    cmd.arg("xbuild").arg("--release");
+    cmd.arg("--verbose");
+    cmd.arg(format!("--manifest-path={}", manifest_path.display()));
+    cmd.arg(format!(
+        "--target={}",
+        dir.join("../..").join(target).display()
+    ));
+    cmd.arg("-Z").arg("unstable-options");
+    cmd.arg("--out-dir").arg(&out_dir);
+    cmd.arg("--target-dir")
+        .arg(out_path.join("target").join(dir_name));
+    cmd.env_remove("RUSTFLAGS");
+    cmd.env(
+        "XBUILD_SYSROOT_PATH",
+        out_path.join("target").join(dir_name).join("sysroot"),
+    );
+    let status = cmd.status().unwrap();
+    assert!(status.success());
+
+    // localize symbols
+    let mut cmd = Command::new(objcopy);
+    for symbol in global_symbols {
+        cmd.arg("-G").arg(symbol);
+    }
+    cmd.arg(out_path.join(format!("lib{}.a", dir_name)));
+    let status = cmd.status().unwrap();
+    assert!(status.success());
+
+    // emit linker flags
+    println!("cargo:rustc-link-search=native={}", out_dir);
+    println!("cargo:rustc-link-lib=static={}", dir_name);
+}