Embed bios and uefi binaries (#395)

Author: mysteriouslyseeing

build.rs

@@ -21,7 +21,6 @@ async fn bios_main() {
     // BIOS crates don't have enough dependencies to utilize all cores on modern
     // CPUs. So by running the build commands in parallel, we increase the number
     // of utilized cores.)
-    #[cfg(not(docsrs_dummy_build))]
     let (bios_boot_sector_path, bios_stage_2_path, bios_stage_3_path, bios_stage_4_path) = (
         build_bios_boot_sector(&out_dir),
         build_bios_stage_2(&out_dir),
@@ -30,14 +29,6 @@ async fn bios_main() {
     )
         .join()
         .await;
-    // dummy implementations because docsrs builds have no network access
-    #[cfg(docsrs_dummy_build)]
-    let (bios_boot_sector_path, bios_stage_2_path, bios_stage_3_path, bios_stage_4_path) = (
-        PathBuf::new(),
-        PathBuf::new(),
-        PathBuf::new(),
-        PathBuf::new(),
-    );
     println!(
         "cargo:rustc-env=BIOS_BOOT_SECTOR_PATH={}",
         bios_boot_sector_path.display()
@@ -60,11 +51,7 @@ async fn bios_main() {
 async fn uefi_main() {
     let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
 
-    #[cfg(not(docsrs_dummy_build))]
     let uefi_path = build_uefi_bootloader(&out_dir).await;
-    // dummy implementation because docsrs builds have no network access
-    #[cfg(docsrs_dummy_build)]
-    let uefi_path = PathBuf::new();
 
     println!(
         "cargo:rustc-env=UEFI_BOOTLOADER_PATH={}",
@@ -109,6 +96,26 @@ async fn build_uefi_bootloader(out_dir: &Path) -> PathBuf {
     }
 }
 
+// dummy implementation because docsrs builds have no network access.
+// This will put an empty file in out_dir and return its path.
+#[cfg(docsrs_dummy_build)]
+#[cfg(feature = "uefi")]
+async fn build_uefi_bootloader(out_dir: &Path) -> PathBuf {
+    use std::fs::File;
+
+    let path = out_dir.join("bootloader-dummy-bootloader-uefi");
+
+    if File::create(&path).is_err() {
+        panic!("Failed to create dummy uefi bootloader");
+    }
+    assert!(
+        path.exists(),
+        "uefi bootloader dummy file does not exist after file creation"
+    );
+
+    path
+}
+
 #[cfg(not(docsrs_dummy_build))]
 #[cfg(feature = "bios")]
 async fn build_bios_boot_sector(out_dir: &Path) -> PathBuf {
@@ -153,6 +160,26 @@ async fn build_bios_boot_sector(out_dir: &Path) -> PathBuf {
     convert_elf_to_bin(elf_path).await
 }
 
+// dummy implementation because docsrs builds have no network access.
+// This will put an empty file in out_dir and return its path.
+#[cfg(docsrs_dummy_build)]
+#[cfg(feature = "bios")]
+async fn build_bios_boot_sector(out_dir: &Path) -> PathBuf {
+    use std::fs::File;
+
+    let path = out_dir.join("bootloader-dummy-bios-boot-sector");
+
+    if File::create(&path).is_err() {
+        panic!("Failed to create dummy bios boot sector");
+    }
+    assert!(
+        path.exists(),
+        "bios boot sector dummy file does not exist after file creation"
+    );
+
+    path
+}
+
 #[cfg(not(docsrs_dummy_build))]
 #[cfg(feature = "bios")]
 async fn build_bios_stage_2(out_dir: &Path) -> PathBuf {
@@ -199,6 +226,26 @@ async fn build_bios_stage_2(out_dir: &Path) -> PathBuf {
     convert_elf_to_bin(elf_path).await
 }
 
+// dummy implementation because docsrs builds have no network access.
+// This will put an empty file in out_dir and return its path.
+#[cfg(docsrs_dummy_build)]
+#[cfg(feature = "bios")]
+async fn build_bios_stage_2(out_dir: &Path) -> PathBuf {
+    use std::fs::File;
+
+    let path = out_dir.join("bootloader-dummy-bios-stage-2");
+
+    if File::create(&path).is_err() {
+        panic!("Failed to create dummy bios second stage");
+    }
+    assert!(
+        path.exists(),
+        "bios second stage dummy file does not exist after file creation"
+    );
+
+    path
+}
+
 #[cfg(not(docsrs_dummy_build))]
 #[cfg(feature = "bios")]
 async fn build_bios_stage_3(out_dir: &Path) -> PathBuf {
@@ -241,6 +288,26 @@ async fn build_bios_stage_3(out_dir: &Path) -> PathBuf {
     convert_elf_to_bin(elf_path).await
 }
 
+// dummy implementation because docsrs builds have no network access.
+// This will put an empty file in out_dir and return its path.
+#[cfg(docsrs_dummy_build)]
+#[cfg(feature = "bios")]
+async fn build_bios_stage_3(out_dir: &Path) -> PathBuf {
+    use std::fs::File;
+
+    let path = out_dir.join("bootloader-dummy-bios-stage-3");
+
+    if File::create(&path).is_err() {
+        panic!("Failed to create dummy bios stage-3");
+    }
+    assert!(
+        path.exists(),
+        "bios stage-3 dummy file does not exist after file creation"
+    );
+
+    path
+}
+
 #[cfg(not(docsrs_dummy_build))]
 #[cfg(feature = "bios")]
 async fn build_bios_stage_4(out_dir: &Path) -> PathBuf {
@@ -284,6 +351,26 @@ async fn build_bios_stage_4(out_dir: &Path) -> PathBuf {
     convert_elf_to_bin(elf_path).await
 }
 
+// dummy implementation because docsrs builds have no network access.
+// This will put an empty file in out_dir and return its path.
+#[cfg(docsrs_dummy_build)]
+#[cfg(feature = "bios")]
+async fn build_bios_stage_4(out_dir: &Path) -> PathBuf {
+    use std::fs::File;
+
+    let path = out_dir.join("bootloader-dummy-bios-stage-4");
+
+    if File::create(&path).is_err() {
+        panic!("Failed to create dummy bios stage-4");
+    }
+    assert!(
+        path.exists(),
+        "bios stage-4 dummy file does not exist after file creation"
+    );
+
+    path
+}
+
 #[cfg(not(docsrs_dummy_build))]
 #[cfg(feature = "bios")]
 async fn convert_elf_to_bin(elf_path: PathBuf) -> PathBuf {

src/file_data_source.rs

@@ -11,6 +11,7 @@ use std::{fs, io};
 pub enum FileDataSource {
     File(PathBuf),
     Data(Vec<u8>),
+    Bytes(&'static [u8]),
 }
 
 impl Debug for FileDataSource {
@@ -22,6 +23,9 @@ impl Debug for FileDataSource {
             FileDataSource::Data(d) => {
                 f.write_fmt(format_args!("data source: {} raw bytes ", d.len()))
             }
+            FileDataSource::Bytes(b) => {
+                f.write_fmt(format_args!("data source: {} raw bytes ", b.len()))
+            }
         }
     }
 }
@@ -34,6 +38,7 @@ impl FileDataSource {
                 .with_context(|| format!("failed to read metadata of file `{}`", path.display()))?
                 .len(),
             FileDataSource::Data(v) => v.len() as u64,
+            FileDataSource::Bytes(s) => s.len() as u64,
         })
     }
     /// Copy this data source to the specified target that implements io::Write
@@ -51,6 +56,10 @@ impl FileDataSource {
                 let mut cursor = Cursor::new(contents);
                 io::copy(&mut cursor, target)?;
             }
+            FileDataSource::Bytes(contents) => {
+                let mut cursor = Cursor::new(contents);
+                io::copy(&mut cursor, target)?;
+            }
         };
 
         Ok(())

src/lib.rs

@@ -41,6 +41,17 @@ const KERNEL_FILE_NAME: &str = "kernel-x86_64";
 const RAMDISK_FILE_NAME: &str = "ramdisk";
 const CONFIG_FILE_NAME: &str = "boot.json";
 
+#[cfg(feature = "uefi")]
+const UEFI_BOOTLOADER: &[u8] = include_bytes!(env!("UEFI_BOOTLOADER_PATH"));
+#[cfg(feature = "bios")]
+const BIOS_BOOT_SECTOR: &[u8] = include_bytes!(env!("BIOS_BOOT_SECTOR_PATH"));
+#[cfg(feature = "bios")]
+const BIOS_STAGE_2: &[u8] = include_bytes!(env!("BIOS_STAGE_2_PATH"));
+#[cfg(feature = "bios")]
+const BIOS_STAGE_3: &[u8] = include_bytes!(env!("BIOS_STAGE_3_PATH"));
+#[cfg(feature = "bios")]
+const BIOS_STAGE_4: &[u8] = include_bytes!(env!("BIOS_STAGE_4_PATH"));
+
 /// Allows creating disk images for a specified set of files.
 ///
 /// It can currently create `MBR` (BIOS), `GPT` (UEFI), and `TFTP` (UEFI) images.
@@ -98,28 +109,19 @@ impl DiskImageBuilder {
     #[cfg(feature = "bios")]
     /// Create an MBR disk image for booting on BIOS systems.
     pub fn create_bios_image(&self, image_path: &Path) -> anyhow::Result<()> {
-        const BIOS_STAGE_3: &str = "boot-stage-3";
-        const BIOS_STAGE_4: &str = "boot-stage-4";
-        let bootsector_path = Path::new(env!("BIOS_BOOT_SECTOR_PATH"));
-        let stage_2_path = Path::new(env!("BIOS_STAGE_2_PATH"));
-        let stage_3_path = Path::new(env!("BIOS_STAGE_3_PATH"));
-        let stage_4_path = Path::new(env!("BIOS_STAGE_4_PATH"));
+        const BIOS_STAGE_3_NAME: &str = "boot-stage-3";
+        const BIOS_STAGE_4_NAME: &str = "boot-stage-4";
+        let stage_3 = FileDataSource::Bytes(BIOS_STAGE_3);
+        let stage_4 = FileDataSource::Bytes(BIOS_STAGE_4);
         let mut internal_files = BTreeMap::new();
-        internal_files.insert(
-            BIOS_STAGE_3,
-            FileDataSource::File(stage_3_path.to_path_buf()),
-        );
-        internal_files.insert(
-            BIOS_STAGE_4,
-            FileDataSource::File(stage_4_path.to_path_buf()),
-        );
-
+        internal_files.insert(BIOS_STAGE_3_NAME, stage_3);
+        internal_files.insert(BIOS_STAGE_4_NAME, stage_4);
         let fat_partition = self
             .create_fat_filesystem_image(internal_files)
             .context("failed to create FAT partition")?;
         mbr::create_mbr_disk(
-            bootsector_path,
-            stage_2_path,
+            BIOS_BOOT_SECTOR,
+            BIOS_STAGE_2,
             fat_partition.path(),
             image_path,
         )
@@ -135,12 +137,9 @@ impl DiskImageBuilder {
     /// Create a GPT disk image for booting on UEFI systems.
     pub fn create_uefi_image(&self, image_path: &Path) -> anyhow::Result<()> {
         const UEFI_BOOT_FILENAME: &str = "efi/boot/bootx64.efi";
-        let bootloader_path = Path::new(env!("UEFI_BOOTLOADER_PATH"));
+
         let mut internal_files = BTreeMap::new();
-        internal_files.insert(
-            UEFI_BOOT_FILENAME,
-            FileDataSource::File(bootloader_path.to_path_buf()),
-        );
+        internal_files.insert(UEFI_BOOT_FILENAME, FileDataSource::Bytes(UEFI_BOOTLOADER));
         let fat_partition = self
             .create_fat_filesystem_image(internal_files)
             .context("failed to create FAT partition")?;
@@ -159,15 +158,13 @@ impl DiskImageBuilder {
         use std::{fs, ops::Deref};
 
         const UEFI_TFTP_BOOT_FILENAME: &str = "bootloader";
-        let bootloader_path = Path::new(env!("UEFI_BOOTLOADER_PATH"));
         fs::create_dir_all(tftp_path)
             .with_context(|| format!("failed to create out dir at {}", tftp_path.display()))?;
 
         let to = tftp_path.join(UEFI_TFTP_BOOT_FILENAME);
-        fs::copy(bootloader_path, &to).with_context(|| {
+        fs::write(&to, UEFI_BOOTLOADER).with_context(|| {
             format!(
-                "failed to copy bootloader from {} to {}",
-                bootloader_path.display(),
+                "failed to copy bootloader from the embedded binary to {}",
                 to.display()
             )
         })?;

src/mbr.rs

@@ -5,15 +5,17 @@ use std::{
     io::{self, Seek, SeekFrom},
     path::Path,
 };
+
 const SECTOR_SIZE: u32 = 512;
 
 pub fn create_mbr_disk(
-    bootsector_path: &Path,
-    second_stage_path: &Path,
+    bootsector_binary: &[u8],
+    second_stage_binary: &[u8],
     boot_partition_path: &Path,
     out_mbr_path: &Path,
 ) -> anyhow::Result<()> {
-    let mut boot_sector = File::open(bootsector_path).context("failed to open boot sector")?;
+    use std::io::Cursor;
+    let mut boot_sector = Cursor::new(bootsector_binary);
     let mut mbr =
         mbrman::MBR::read_from(&mut boot_sector, SECTOR_SIZE).context("failed to read MBR")?;
 
@@ -23,12 +25,9 @@ pub fn create_mbr_disk(
         }
     }
 
-    let mut second_stage =
-        File::open(second_stage_path).context("failed to open second stage binary")?;
-    let second_stage_size = second_stage
-        .metadata()
-        .context("failed to read file metadata of second stage")?
-        .len();
+    let mut second_stage = Cursor::new(second_stage_binary);
+    let second_stage_size = second_stage_binary.len() as u64;
+
     let second_stage_start_sector = 1;
     let second_stage_sectors = ((second_stage_size - 1) / u64::from(SECTOR_SIZE) + 1)
         .try_into()