diff options
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/DisablePaging64.S | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/MdePkg/Library/BaseLib/X64/DisablePaging64.S b/MdePkg/Library/BaseLib/X64/DisablePaging64.S index 038af71d2f..242c0a07bb 100644 --- a/MdePkg/Library/BaseLib/X64/DisablePaging64.S +++ b/MdePkg/Library/BaseLib/X64/DisablePaging64.S @@ -37,8 +37,19 @@ ASM_GLOBAL ASM_PFX(InternalX86DisablePaging64)
ASM_PFX(InternalX86DisablePaging64):
- cli
- lea L1(%rip), %r10
+ cli + lea L1(%rip), %rsi # rsi <- The start address of transition code + mov 0x28(%rsp), %rdi # rdi <- New stack + sub $64, %rdi # rdi <- use 64 byte in stack to hold transition code + mov %rdi, %r10 # r10 <- The start address of transicition code below 4G + lea _mTransitionEnd(%rip), %rax # rax <- end of transition code + sub %rsi, %rax # rax <- The size of transition piece code + push %rcx # save rcx to stack + mov %rax, %rcx # rcx <- The size of transition piece code + rep + movsb # copy transition code to (new stack - 64byte) below 4G + pop %rcx # restore rcx +
mov %r8d, %esi
mov %r9d, %edi
mov 0x28(%rsp), %eax # eax <- New Stack
@@ -64,4 +75,4 @@ L1: push %rsi # push Context1
callq *%rbx # transfer control to EntryPoint
jmp . # no one should get here
-
+
_mTransitionEnd : |