From f703d915cd4c0f3dc332c12a71b8013bce8e7f8b Mon Sep 17 00:00:00 2001
From: Zhang Junyang <junyang@stu.pku.edu.cn>
Date: Thu, 20 Jun 2024 15:05:05 +0000
Subject: [PATCH] Solve the haunting i386 data layout in Linux legacy boot

---
 .../builder/src/x86_64-i386_pm-none.json       |  2 +-
 .../setup/src/x86/amd64_efi/relocation.rs      | 18 +-----------------
 2 files changed, 2 insertions(+), 18 deletions(-)

diff --git a/framework/libs/linux-bzimage/builder/src/x86_64-i386_pm-none.json b/framework/libs/linux-bzimage/builder/src/x86_64-i386_pm-none.json
index 4a5800775..e7ab8fa69 100644
--- a/framework/libs/linux-bzimage/builder/src/x86_64-i386_pm-none.json
+++ b/framework/libs/linux-bzimage/builder/src/x86_64-i386_pm-none.json
@@ -1,6 +1,6 @@
 {
     "llvm-target": "i386-unknown-none",
-    "data-layout": "e-m:e-i32:32-f80:128-n8:16:32-S128-p:32:32",
+    "data-layout": "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-i128:128-f64:32:64-f80:32-n8:16:32-S128",
     "cpu": "i386",
     "arch": "x86",
     "dynamic-linking": false,
diff --git a/framework/libs/linux-bzimage/setup/src/x86/amd64_efi/relocation.rs b/framework/libs/linux-bzimage/setup/src/x86/amd64_efi/relocation.rs
index c131fe699..cd884d381 100644
--- a/framework/libs/linux-bzimage/setup/src/x86/amd64_efi/relocation.rs
+++ b/framework/libs/linux-bzimage/setup/src/x86/amd64_efi/relocation.rs
@@ -15,23 +15,7 @@ fn get_rela_array() -> &'static [Elf64Rela] {
     }
     let start = __rela_dyn_start as *const Elf64Rela;
     let end = __rela_dyn_end as *const Elf64Rela;
-    // FIXME: 2023/11/29
-    // There should be a Rust compiler bug that makes the calculation of len incorrect.
-    // The most sound implementation only works in debug mode.
-    // let len = unsafe { end.offset_from(start) } as usize;
-    // The inline asm solution is a workaround.
-    let len = unsafe {
-        let len: usize;
-        core::arch::asm!("
-                mov {len}, {end}
-                sub {len}, {start}
-            ",
-            len = out(reg) len,
-            end = in(reg) end,
-            start = in(reg) start,
-        );
-        len / core::mem::size_of::<Elf64Rela>()
-    };
+    let len = unsafe { end.offset_from(start) } as usize;
     #[cfg(feature = "debug_print")]
     unsafe {
         use crate::console::{print_hex, print_str};