diff options
Diffstat (limited to 'roms/edk2/OvmfPkg/Library/LoadLinuxLib/X64/JumpToKernel.nasm')
| -rw-r--r-- | roms/edk2/OvmfPkg/Library/LoadLinuxLib/X64/JumpToKernel.nasm | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/roms/edk2/OvmfPkg/Library/LoadLinuxLib/X64/JumpToKernel.nasm b/roms/edk2/OvmfPkg/Library/LoadLinuxLib/X64/JumpToKernel.nasm new file mode 100644 index 000000000..6e37f21db --- /dev/null +++ b/roms/edk2/OvmfPkg/Library/LoadLinuxLib/X64/JumpToKernel.nasm @@ -0,0 +1,87 @@ +;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
+;
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+ DEFAULT REL
+ SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; JumpToKernel (
+; VOID *KernelStart, // rcx
+; VOID *KernelBootParams // rdx
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(JumpToKernel)
+ASM_PFX(JumpToKernel):
+
+ ; Set up for executing kernel. BP in %esi, entry point on the stack
+ ; (64-bit when the 'ret' will use it as 32-bit, but we're little-endian)
+ mov rsi, rdx
+ push rcx
+
+ ; Jump into the compatibility mode CS
+ push 0x10
+ lea rax, [.0]
+ push rax
+ DB 0x48, 0xcb ; retfq
+
+.0:
+ ; Now in compatibility mode.
+
+ DB 0xb8, 0x18, 0x0, 0x0, 0x0 ; movl $0x18, %eax
+ DB 0x8e, 0xd8 ; movl %eax, %ds
+ DB 0x8e, 0xc0 ; movl %eax, %es
+ DB 0x8e, 0xe0 ; movl %eax, %fs
+ DB 0x8e, 0xe8 ; movl %eax, %gs
+ DB 0x8e, 0xd0 ; movl %eax, %ss
+
+ ; Disable paging
+ DB 0xf, 0x20, 0xc0 ; movl %cr0, %eax
+ DB 0xf, 0xba, 0xf8, 0x1f ; btcl $31, %eax
+ DB 0xf, 0x22, 0xc0 ; movl %eax, %cr0
+
+ ; Disable long mode in EFER
+ DB 0xb9, 0x80, 0x0, 0x0, 0xc0 ; movl $0x0c0000080, %ecx
+ DB 0xf, 0x32 ; rdmsr
+ DB 0xf, 0xba, 0xf8, 0x8 ; btcl $8, %eax
+ DB 0xf, 0x30 ; wrmsr
+
+ ; Disable PAE
+ DB 0xf, 0x20, 0xe0 ; movl %cr4, %eax
+ DB 0xf, 0xba, 0xf8, 0x5 ; btcl $5, %eax
+ DB 0xf, 0x22, 0xe0 ; movl %eax, %cr4
+
+ DB 0x31, 0xed ; xor %ebp, %ebp
+ DB 0x31, 0xff ; xor %edi, %edi
+ DB 0x31, 0xdb ; xor %ebx, %ebx
+ DB 0xc3 ; ret
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; JumpToUefiKernel (
+; EFI_HANDLE ImageHandle, // rcx
+; EFI_SYSTEM_TABLE *SystemTable, // rdx
+; VOID *KernelBootParams // r8
+; VOID *KernelStart, // r9
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(JumpToUefiKernel)
+ASM_PFX(JumpToUefiKernel):
+
+ mov rdi, rcx
+ mov rsi, rdx
+ mov rdx, r8
+ xor rax, rax
+ mov eax, [r8 + 0x264]
+ add r9, rax
+ add r9, 0x200
+ call r9
+ ret
+
|