boot: Add EFISTUB and refactor boot protocols

2026-10-27 22:50:43 +01:00
parent 6827dc309e
commit 196543c3d3
40 changed files with 1923 additions and 208 deletions
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: ISC
+
+    .intel_syntax noprefix
+    .text
+
+    .globl _start
+    .type _start, @function
+_start:
+    // Align the stack pointer
+    push rbp
+    mov rbp, rsp
+    push rdi
+    push rsi
+    push rbx
+    push r12
+    and rsp, -16
+    cld
+
+    mov rbx, rcx
+    mov r12, rdx
+
+    // Clear .bss
+    lea rdi, [rip + __bss_start]
+    lea rcx, [rip + __bss_end]
+    sub rcx, rdi
+    xor eax, eax
+    rep stosb
+
+    // Self-relocate
+    lea rdi, [rip + __image_base]
+    lea rsi, [rip + _DYNAMIC]
+    call efistub_relocate
+    test rax, rax
+    jnz 1f
+
+    mov rdi, rbx
+    mov rsi, r12
+    call efi_main
+
+1:
+    lea rsp, [rbp - 32]
+    pop r12
+    pop rbx
+    pop rsi
+    pop rdi
+    pop rbp
+    ret
+    .size _start, . - _start