\r
-#include <BaseLibInternals.h>\r
+#include "BaseLibInternals.h"\r
\r
;------------------------------------------------------------------------------\r
;\r
-; Copyright (c) 2006, Intel Corporation\r
-; All rights reserved. This program and the accompanying materials\r
+; Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r
+; This program and the accompanying materials\r
; are licensed and made available under the terms and conditions of the BSD License\r
; which accompanies this distribution. The full text of the license may be found at\r
-; http://opensource.org/licenses/bsd-license.php\r
+; http://opensource.org/licenses/bsd-license.php.\r
;\r
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
or al, 2\r
out 92h, al ; deactivate A20M#\r
@2:\r
- mov eax, ss\r
+ mov ax, ss\r
lea bp, [esp + sizeof (IA32_REGS)]\r
;\r
; rsi in the following 2 instructions is indeed bp in 16-bit code\r
@64Eip DD ?\r
SavedCs DW ?\r
@64BitCode:\r
- mov rsp, r8 ; restore stack\r
+ db 090h \r
+ db 067h, 0bch ; mov esp, imm32\r
+SavedSp DD ? ; restore stack\r
+ nop\r
ret\r
_BackFromUserCode ENDP\r
\r
; );\r
;------------------------------------------------------------------------------\r
InternalAsmThunk16 PROC USES rbp rbx rsi rdi\r
- mov r10d, ds ; r9 ~ r11 are not accessible in 16-bit\r
- mov r11d, es ; so use them for saving seg registers\r
- mov r9d, ss\r
+ mov rbx, ds\r
+ push rbx ; Save ds segment register on the stack\r
+ mov rbx, es\r
+ push rbx ; Save es segment register on the stack\r
+ mov rbx, ss\r
+ push rbx ; Save ss segment register on the stack\r
+ \r
push fs\r
push gs\r
mov rsi, rcx\r
shl eax, 12 ; segment address in high order 16 bits\r
lea ax, [rdx + (_BackFromUserCode - m16Start)] ; offset address\r
stosd ; [edi] <- return address of user code\r
- sgdt fword ptr [rcx + (SavedGdt - SavedCr4)]\r
- sidt fword ptr [rsp + 38h] ; save IDT stack in argument space\r
+ \r
+ sgdt fword ptr [rsp + 60h] ; save GDT stack in argument space\r
+ movzx r10, word ptr [rsp + 60h] ; r10 <- GDT limit \r
+ lea r11, [rcx + (InternalAsmThunk16 - SavedCr4) + 0xf]\r
+ and r11, 0xfffffff0 ; r11 <- 16-byte aligned shadowed GDT table in real mode buffer\r
+ \r
+ mov word ptr [rcx + (SavedGdt - SavedCr4)], r10w ; save the limit of shadowed GDT table\r
+ mov qword ptr [rcx + (SavedGdt - SavedCr4) + 2], r11 ; save the base address of shadowed GDT table\r
+ \r
+ mov rsi, qword ptr [rsp + 62h] ; rsi <- the original GDT base address\r
+ xchg rcx, r10 ; save rcx to r10 and initialize rcx to be the limit of GDT table\r
+ inc rcx ; rcx <- the size of memory to copy\r
+ xchg rdi, r11 ; save rdi to r11 and initialize rdi to the base address of shadowed GDT table\r
+ rep movsb ; perform memory copy to shadow GDT table\r
+ mov rcx, r10 ; restore the orignal rcx before memory copy\r
+ mov rdi, r11 ; restore the original rdi before memory copy\r
+ \r
+ sidt fword ptr [rsp + 50h] ; save IDT stack in argument space\r
mov rax, cr0\r
mov [rcx + (SavedCr0 - SavedCr4)], eax\r
and eax, 7ffffffeh ; clear PE, PG bits\r
push r8\r
mov r8d, cs\r
mov [rcx + (SavedCs - SavedCr4)], r8w\r
- mov r8, rsp\r
+ mov [rcx + (SavedSp - SavedCr4)], esp\r
jmp fword ptr [rcx + (_EntryPoint - SavedCr4)]\r
@RetFromRealMode:\r
popfq\r
- lidt fword ptr [rsp + 38h] ; restore protected mode IDTR\r
+ lgdt fword ptr [rsp + 60h] ; restore protected mode GDTR\r
+ lidt fword ptr [rsp + 50h] ; restore protected mode IDTR\r
lea eax, [rbp - sizeof (IA32_REGS)]\r
pop gs\r
pop fs\r
- mov ss, r9d\r
- mov es, r11d\r
- mov ds, r10d\r
+ pop rbx\r
+ mov ss, rbx\r
+ pop rbx\r
+ mov es, rbx\r
+ pop rbx\r
+ mov ds, rbx\r
ret\r
InternalAsmThunk16 ENDP\r
\r