build: better fat32 image handling

Cargo.lock

@@ -90,6 +90,21 @@ dependencies = [
  "spinning_top",
 ]
 
+[[package]]
+name = "android-tzdata"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999941b234f3131b00bc13c22d06e8c5ff726d1b6318ac7eb276997bbb4fef0"
+
+[[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "anstream"
 version = "0.6.13"
@@ -210,6 +225,12 @@ dependencies = [
  "rustversion",
 ]
 
+[[package]]
+name = "bumpalo"
+version = "3.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79296716171880943b8470b5f8d03aa55eb2e645a4874bdbb28adb49162e012c"
+
 [[package]]
 name = "bytemuck"
 version = "1.14.3"
@@ -252,6 +273,20 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chrono"
+version = "0.4.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a0d04d43504c61aa6c7531f1871dd0d418d91130162063b789da00fd7057a5e"
+dependencies = [
+ "android-tzdata",
+ "iana-time-zone",
+ "js-sys",
+ "num-traits",
+ "wasm-bindgen",
+ "windows-targets",
+]
+
 [[package]]
 name = "clap"
 version = "4.5.2"
@@ -307,6 +342,12 @@ dependencies = [
  "rustc-std-workspace-core",
 ]
 
+[[package]]
+name = "core-foundation-sys"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06ea2b9bc92be3c2baa9334a323ebca2d6f074ff852cd1d7b11064035cd3868f"
+
 [[package]]
 name = "crossbeam-queue"
 version = "0.3.11"
@@ -467,6 +508,18 @@ version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25cbce373ec4653f1a01a31e8a5e5ec0c622dc27ff9c4e6606eefef5cbbed4a5"
 
+[[package]]
+name = "fatfs"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05669f8e7e2d7badc545c513710f0eba09c2fbef683eb859fd79c46c355048e0"
+dependencies = [
+ "bitflags 1.3.2",
+ "byteorder",
+ "chrono",
+ "log",
+]
+
 [[package]]
 name = "fdt-rs"
 version = "0.4.5"
@@ -516,6 +569,15 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fscommon"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "315ce685aca5ddcc5a3e7e436ef47d4a5d0064462849b6f0f628c28140103531"
+dependencies = [
+ "log",
+]
+
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -631,6 +693,29 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "iana-time-zone"
+version = "0.1.60"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7ffbb5a1b541ea2561f8c41c087286cc091e21e556a4f09a8f6cbf17b69b141"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "idna"
 version = "0.5.0"
@@ -684,6 +769,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "js-sys"
+version = "0.3.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29c15563dc2726973df627357ce0c9ddddbea194836909d655df6a75d2cf296d"
+dependencies = [
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "kernel-arch"
 version = "0.1.0"
@@ -1599,6 +1693,60 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4be2531df63900aeb2bca0daaaddec08491ee64ceecbee5076636a3b026795a8"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "614d787b966d3989fa7bb98a654e369c762374fd3213d212cfc0251257e747da"
+dependencies = [
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.52",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1f8823de937b71b9460c0c34e25f3da88250760bec0ebac694b49997550d726"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.52",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
+
 [[package]]
 name = "which"
 version = "6.0.0"
@@ -1643,6 +1791,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-core"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33ab640c8d7e35bf8ba19b884ba838ceb4fba93a4e8c65a9059d08afcfc683d9"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
@@ -1757,6 +1914,8 @@ dependencies = [
  "clap",
  "dependency-graph",
  "env_logger",
+ "fatfs",
+ "fscommon",
  "git2",
  "log",
  "qemu",

xtask/Cargo.toml

@@ -19,3 +19,5 @@ env_logger = "0.11.2"
 log = "0.4.21"
 dependency-graph = "0.1.5"
 semver = { version = "1.0.22", features = ["serde"] }
+fatfs = "0.3.6"
+fscommon = "0.1.1"

xtask/src/build/x86_64.rs

@@ -1,4 +1,10 @@
-use std::path::PathBuf;
+use std::{
+    fs::{self, File, OpenOptions},
+    io::{self, BufReader, BufWriter},
+    path::{Path, PathBuf},
+};
+
+use fscommon::BufStream;
 
 use crate::{build::cargo::CargoBuilder, env::BuildEnv, error::Error, util};
 
@@ -15,6 +21,26 @@ fn build_yboot(env: &BuildEnv) -> Result<YbootBuilt, Error> {
     Ok(YbootBuilt(binary))
 }
 
+fn copy_into_fat(
+    dir: &fatfs::Dir<'_, BufStream<File>>,
+    src: impl AsRef<Path>,
+    dst: impl AsRef<str>,
+) -> Result<(), Error> {
+    let src = src.as_ref();
+    let dst = dst.as_ref();
+
+    log::debug!("{} -> {}", src.display(), dst);
+    let mut dst = dir.create_file(dst)?;
+    let mut src = BufReader::new(File::open(src)?);
+
+    dst.truncate()?;
+    let mut dst = BufWriter::new(dst);
+
+    io::copy(&mut src, &mut dst)?;
+
+    Ok(())
+}
+
 fn build_uefi_image(
     env: &BuildEnv,
     yboot: YbootBuilt,
@@ -24,6 +50,7 @@ fn build_uefi_image(
     log::info!("Building x86-64 UEFI image");
     let image_path = env.kernel_output_dir.join("image.fat32");
 
+    if !image_path.exists() {
         util::run_external_command(
             "dd",
             [
@@ -39,46 +66,21 @@ fn build_uefi_image(
             ["-F32".as_ref(), image_path.as_os_str()],
             false,
         )?;
-    util::run_external_command(
+    }
-        "mmd",
+
-        ["-i".as_ref(), image_path.as_os_str(), "::EFI".as_ref()],
+    let image_file = OpenOptions::new()
-        false,
+        .read(true)
-    )?;
+        .write(true)
-    util::run_external_command(
+        .open(&image_path)?;
-        "mmd",
+    let buf_stream = fscommon::BufStream::new(image_file);
-        ["-i".as_ref(), image_path.as_os_str(), "::EFI/Boot".as_ref()],
+    let fs = fatfs::FileSystem::new(buf_stream, fatfs::FsOptions::new())?;
-        false,
+
-    )?;
+    let root_dir = fs.root_dir();
-    util::run_external_command(
+
-        "mcopy",
+    let boot_dir = root_dir.create_dir("EFI")?.create_dir("Boot")?;
-        [
+    copy_into_fat(&boot_dir, &yboot.0, "BootX64.efi")?;
-            "-i".as_ref(),
+    copy_into_fat(&root_dir, &kernel.0 .0, "kernel.elf")?;
-            image_path.as_os_str(),
+    copy_into_fat(&root_dir, &initrd.0, "initrd.img")?;
-            yboot.0.as_os_str(),
-            "::EFI/Boot/BootX64.efi".as_ref(),
-        ],
-        false,
-    )?;
-    util::run_external_command(
-        "mcopy",
-        [
-            "-i".as_ref(),
-            image_path.as_os_str(),
-            kernel.0 .0.as_os_str(),
-            "::kernel.elf".as_ref(),
-        ],
-        false,
-    )?;
-    util::run_external_command(
-        "mcopy",
-        [
-            "-i".as_ref(),
-            image_path.as_os_str(),
-            initrd.0.as_os_str(),
-            "::initrd.img".as_ref(),
-        ],
-        false,
-    )?;
 
     Ok(ImageBuilt(image_path))
 }