Successfully entered setup rust entrypoint

Cargo.lock

@@ -647,6 +647,7 @@ dependencies = [
  "volatile",
  "x86",
  "x86_64",
+ "xmas-elf",
 ]
 
 [[package]]

Makefile

@@ -58,7 +58,6 @@ export
 
 # Toolchain variables that are used when building the Linux setup header
 export CARGO := cargo
-export OBJCOPY := objcopy
 
 .PHONY: all setup build tools run test docs check clean
 

framework/jinux-frame/Cargo.toml

@@ -30,5 +30,8 @@ aml = "0.16.3"
 multiboot2 = "0.16.0"
 rsdp = "2.0.0"
 
+[build-dependencies]
+xmas-elf = "0.8.0"
+
 [features]
 intel_tdx = ["dep:tdx-guest"]

framework/jinux-frame/build.rs

@@ -1,14 +1,26 @@
-use std::{error::Error, io::Write, path::PathBuf};
+use std::{
+    error::Error,
+    io::{Seek, Write},
+    path::{Path, PathBuf},
+};
+
+use xmas_elf::program::{ProgramHeader, SegmentData};
+
+const SETUP32_LMA: usize = 0x100000;
 
 fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
-    build_linux_setup_header()?;
+    let source_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+    build_linux_setup_header(&source_dir, &out_dir)?;
+    copy_to_raw_binary(&out_dir)?;
     Ok(())
 }
 
-fn build_linux_setup_header() -> Result<(), Box<dyn Error + Send + Sync>> {
-    // Build the setup header to raw binary.
-    let source_dir = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
-    let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+fn build_linux_setup_header(
+    source_dir: &Path,
+    out_dir: &Path,
+) -> Result<(), Box<dyn Error + Send + Sync>> {
+    // Build the setup header to ELF.
     let setup_crate_dir = source_dir
         .join("src")
         .join("arch")
@@ -26,12 +38,17 @@ fn build_linux_setup_header() -> Result<(), Box<dyn Error + Send + Sync>> {
     let cargo = std::env::var("CARGO").unwrap();
     let mut cmd = std::process::Command::new(cargo);
     cmd.arg("install").arg("jinux-frame-x86-boot-setup");
+    cmd.arg("--debug");
     cmd.arg("--locked");
     cmd.arg("--path").arg(setup_crate_dir.to_str().unwrap());
     cmd.arg("--target").arg(target_json.as_os_str());
     cmd.arg("-Zbuild-std=core,compiler_builtins");
     cmd.arg("-Zbuild-std-features=compiler-builtins-mem");
+    // Specify the installation root.
     cmd.arg("--root").arg(out_dir.as_os_str());
+    // Specify the build target directory to avoid cargo running
+    // into a deadlock reading the workspace files.
+    cmd.arg("--target-dir").arg(out_dir.as_os_str());
     cmd.env_remove("RUSTFLAGS");
     cmd.env_remove("CARGO_ENCODED_RUSTFLAGS");
     let output = cmd.output()?;
@@ -45,31 +62,46 @@ fn build_linux_setup_header() -> Result<(), Box<dyn Error + Send + Sync>> {
         .into());
     }
 
+    Ok(())
+}
+
+/// We need a binary which satisfies `LMA == File_Offset`, and objcopy
+/// does not satisfy us well, so we should parse the ELF and do our own
+/// objcopy job.
+///
+/// Interstingly, the resulting binary should be the same as the memory
+/// dump of the kernel setup header when it's loaded by the bootloader.
+fn copy_to_raw_binary(out_dir: &Path) -> Result<(), Box<dyn Error + Send + Sync>> {
     // Strip the elf header to get the raw header.
     let elf_path = out_dir.join("bin").join("jinux-frame-x86-boot-setup");
     let bin_path = out_dir.join("bin").join("jinux-frame-x86-boot-setup.bin");
 
-    let objcopy = std::env::var("OBJCOPY").unwrap();
-    let mut cmd = std::process::Command::new(objcopy);
-    cmd.arg("-O").arg("binary");
-    cmd.arg("-j").arg(".header");
-    cmd.arg("-j").arg(".text");
-    cmd.arg("-j").arg(".rodata");
-    cmd.arg("-j").arg(".data");
-    cmd.arg("-j").arg(".bss");
-    cmd.arg("-j").arg(".eh_frame");
-    cmd.arg("-j").arg(".eh_frame_hdr");
-    cmd.arg(elf_path.to_str().unwrap());
-    cmd.arg(bin_path.to_str().unwrap());
-    let output = cmd.output()?;
-    if !output.status.success() {
-        std::io::stdout().write_all(&output.stdout).unwrap();
-        std::io::stderr().write_all(&output.stderr).unwrap();
-        return Err(format!(
-            "Failed to strip linux boot header:\n\tcommand `{:?}`\n\treturned {}",
-            cmd, output.status
-        )
-        .into());
+    let elf_file = std::fs::read(elf_path)?;
+    let elf = xmas_elf::ElfFile::new(&elf_file)?;
+
+    let bin_file = std::fs::File::create(bin_path)?;
+    let mut bin_writer = std::io::BufWriter::new(bin_file);
+
+    for ph in elf.program_iter() {
+        let ProgramHeader::Ph32(program) = ph else {
+            return Err("Unexpected program header type".into());
+        };
+        if program.get_type().unwrap() == xmas_elf::program::Type::Load {
+            let dest_file_offset = program.virtual_addr as usize - SETUP32_LMA;
+            bin_writer.seek(std::io::SeekFrom::End(0))?;
+            let cur_file_offset = bin_writer.stream_position().unwrap() as usize;
+            if cur_file_offset < dest_file_offset {
+                let padding = vec![0; dest_file_offset - cur_file_offset];
+                bin_writer.write_all(&padding)?;
+            } else {
+                bin_writer.seek(std::io::SeekFrom::Start(dest_file_offset as u64))?;
+            }
+            let SegmentData::Undefined(header_data) = program.get_data(&elf).unwrap() else {
+                return Err("Unexpected segment data type".into());
+            };
+            bin_writer.write_all(header_data)?;
+        }
     }
+
     Ok(())
 }

framework/jinux-frame/src/arch/x86/boot/linux_boot/setup/src/header.S

@@ -16,7 +16,7 @@
 
 .code16
 .org 0x01f1
-hdr:
+hdr_start:
 SETUP_SECTS = 4
 setup_sects:            .byte SETUP_SECTS
 root_flags:             .word 1
@@ -26,7 +26,7 @@ vid_mode:               .word 0xfffd
 root_dev:               .word 0
 boot_flag:              .word 0xAA55
 jump:                   .byte 0xeb
-jump_addr:              .byte start_of_setup32-jump_addr
+jump_addr:              .byte hdr_end-jump_addr
 magic:                  .ascii "HdrS"
                         .word 0x020f
 realmode_swtch:         .word 0, 0
@@ -58,12 +58,12 @@ pref_address:           .quad 0
 init_size:              .long 0xabababab # at 0x260/4, to be filled by the runner
 handover_offset:        .long 0
 kernel_info_offset:     .long 0
-
+hdr_end:
 // End of header.
 
-// 32-bit setup code starts here.
+// 32-bit setup code starts here, and will be loaded at code32_start (0x100000).
 .code32
-start_of_setup32:
 .org 0x200 * (SETUP_SECTS + 1)
+start_of_setup32:
         .extern _rust_setup_entry
         jmp _rust_setup_entry