diff options
Diffstat (limited to 'MdePkg')
| -rw-r--r-- | MdePkg/Include/Library/BaseLib.h | 41 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/BaseLib.msa | 4 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c | 64 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ebc/Synchronization.c | 57 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ia32/Thunk16.asm | 260 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ipf/CpuBreakpoint.c | 18 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/Ipf/CpuPause.s | 25 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/X64/Thunk16.asm | 298 | ||||
| -rw-r--r-- | MdePkg/Library/BaseLib/x86Thunk.c | 153 |
9 files changed, 664 insertions, 256 deletions
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h index ff663c9..7fb2e64 100644 --- a/MdePkg/Include/Library/BaseLib.h +++ b/MdePkg/Include/Library/BaseLib.h @@ -2969,15 +2969,16 @@ typedef union { // Byte packed structure for an 16-bit real mode thunks
//
typedef struct {
- IA32_REGISTER_SET RealModeState;
+ IA32_REGISTER_SET *RealModeState;
VOID *RealModeBuffer;
- UINTN RealModeBufferSize;
- VOID *CallStack;
- UINTN CallStackSize;
- VOID *RealModeCode;
- UINTN RealModeCodeSize;
+ UINT32 RealModeBufferSize;
+ UINT32 ThunkAttributes;
} THUNK_CONTEXT;
+#define THUNK_ATTRIBUTE_BIG_REAL_MODE 0x00000001
+#define THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 0x00000002
+#define THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL 0x00000004
+
/**
Retrieves CPUID information.
@@ -4799,6 +4800,34 @@ AsmDisablePaging64 ( //
/**
+ Retrieves the properties for 16-bit thunk functions.
+
+ Computes the size of the buffer and stack below 1MB required to use the
+ AsmPrepareThunk16(), AsmThunk16() and AsmPrepareAndThunk16() functions. This
+ buffer size is returned in RealModeBufferSize, and the stack size is returned
+ in ExtraStackSize. If parameters are passed to the 16-bit real mode code,
+ then the actual minimum stack size is ExtraStackSize plus the maximum number
+ of bytes that need to be passed to the 16-bit real mode code.
+
+ If RealModeBufferSize is NULL, then ASSERT().
+ If ExtraStackSize is NULL, then ASSERT().
+
+ @param RealModeBufferSize A pointer to the size of the buffer below 1MB
+ required to use the 16-bit thunk functions.
+ @param ExtraStackSize A pointer to the extra size of stack below 1MB
+ that the 16-bit thunk functions require for
+ temporary storage in the transition to and from
+ 16-bit real mode.
+
+**/
+VOID
+EFIAPI
+AsmGetThunk16Properties (
+ OUT UINT32 *RealModeBufferSize,
+ OUT UINT32 *ExtraStackSize
+ );
+
+/**
Prepares all structures a code required to use AsmThunk16().
Prepares all structures and code required to use AsmThunk16().
diff --git a/MdePkg/Library/BaseLib/BaseLib.msa b/MdePkg/Library/BaseLib/BaseLib.msa index a64eea5..380674a 100644 --- a/MdePkg/Library/BaseLib/BaseLib.msa +++ b/MdePkg/Library/BaseLib/BaseLib.msa @@ -272,6 +272,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. <Filename>Ipf/InterlockedCompareExchange32.s</Filename>
<Filename>Ipf/InterlockedCompareExchange64.s</Filename>
<Filename>Ipf/Synchronization.c</Filename>
+ <Filename>Ipf/CpuPause.s</Filename>
</Arch>
<Arch ArchType="EBC">
<Filename>Math64.c</Filename>
@@ -279,9 +280,10 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. <Filename>SetJumpLongJump.c</Filename>
<Filename>Unaligned.c</Filename>
<Filename>Ebc/CpuBreakpoint.c</Filename>
+ <Filename>Ebc/Synchronization.c</Filename>
</Arch>
</SourceFiles>
- <Includes>
+ <Includes>
<PackageName>MdePkg</PackageName>
</Includes>
<PCDs>
diff --git a/MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c b/MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c index b0b262f..352e1c7 100644 --- a/MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c +++ b/MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c @@ -98,3 +98,67 @@ GetInterruptState ( ASSERT (FALSE);
return FALSE;
}
+
+/**
+ Enables CPU interrupts for the smallest window required to capture any
+ pending interrupts.
+
+ Enables CPU interrupts for the smallest window required to capture any
+ pending interrupts.
+
+**/
+VOID
+EFIAPI
+EnableDisableInterrupts (
+ VOID
+ )
+{
+ EnableInterrupts ();
+ DisableInterrupts ();
+}
+
+/**
+ Requests CPU to pause for a short period of time.
+
+ Requests CPU to pause for a short period of time. Typically used in MP
+ systems to prevent memory starvation while waiting for a spin lock.
+
+**/
+VOID
+EFIAPI
+CpuPause (
+ VOID
+ )
+{
+}
+
+/**
+ Flushes all the Translation Lookaside Buffers(TLB) entries in a CPU.
+
+ Flushes all the Translation Lookaside Buffers(TLB) entries in a CPU.
+
+**/
+VOID
+EFIAPI
+CpuFlushTlb (
+ VOID
+ )
+{
+ ASSERT (FALSE);
+}
+
+/**
+ Places the CPU in a sleep state until an interrupt is received.
+
+ Places the CPU in a sleep state until an interrupt is received. If interrupts
+ are disabled prior to calling this function, then the CPU will be placed in a
+ sleep state indefinitely.
+
+**/
+VOID
+EFIAPI
+CpuSleep (
+ VOID
+ )
+{
+}
diff --git a/MdePkg/Library/BaseLib/Ebc/Synchronization.c b/MdePkg/Library/BaseLib/Ebc/Synchronization.c new file mode 100644 index 0000000..df591b2 --- /dev/null +++ b/MdePkg/Library/BaseLib/Ebc/Synchronization.c @@ -0,0 +1,57 @@ +/** @file
+ Implementation of synchronization functions on EBC.
+
+ Copyright (c) 2006, Intel Corporation<BR>
+ All rights reserved. This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+ Module Name: Synchronization.c
+
+**/
+
+UINT32
+EFIAPI
+InternalSyncCompareExchange32 (
+ IN volatile UINT32 *Value,
+ IN UINT32 CompareValue,
+ IN UINT32 ExchangeValue
+ )
+{
+ return *Value != CompareValue ? *Value :
+ ((*Value = ExchangeValue), CompareValue);
+}
+
+UINT64
+EFIAPI
+InternalSyncCompareExchange64 (
+ IN volatile UINT64 *Value,
+ IN UINT64 CompareValue,
+ IN UINT64 ExchangeValue
+ )
+{
+ return *Value != CompareValue ? *Value :
+ ((*Value = ExchangeValue), CompareValue);
+}
+
+UINT32
+EFIAPI
+InternalSyncIncrement (
+ IN volatile UINT32 *Value
+ )
+{
+ return ++*Value;
+}
+
+UINT32
+EFIAPI
+InternalSyncDecrement (
+ IN volatile UINT32 *Value
+ )
+{
+ return --*Value;
+}
diff --git a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm index 2d62d72..89d4f67 100644 --- a/MdePkg/Library/BaseLib/Ia32/Thunk16.asm +++ b/MdePkg/Library/BaseLib/Ia32/Thunk16.asm @@ -22,34 +22,16 @@ .686p
.model flat,C
- .data
+EXTERNDEF C m16Start:BYTE
+EXTERNDEF C m16Size:WORD
+EXTERNDEF C mThunk16Attr:WORD
+EXTERNDEF C m16Gdt:WORD
+EXTERNDEF C m16GdtrBase:WORD
+EXTERNDEF C mTransition:WORD
-NullSegSel DQ 0
-_16BitCsSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 9bh
- DB 8fh ; 16-bit segment
- DB 0
-_16BitDsSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 93h
- DB 8fh ; 16-bit segment
- DB 0
-GdtEnd LABEL QWORD
-
- .const
-
-_16Gdtr LABEL FWORD
- DW offset GdtEnd - offset NullSegSel - 1
- DD offset NullSegSel
-
-_16Idtr FWORD (1 SHL 10) - 1
-
- .code
+THUNK_ATTRIBUTE_BIG_REAL_MODE EQU 1
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 EQU 2
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL EQU 4
IA32_REGS STRUC 4t
_EDI DD ?
@@ -70,93 +52,165 @@ _CS DW ? _SS DW ?
IA32_REGS ENDS
-InternalAsmThunk16 PROC USES ebp ebx esi edi ds es fs gs
- mov esi, [esp + 36] ; esi <- RegSet
- push sizeof (IA32_REGS)
- pop ecx
- movzx edx, (IA32_REGS ptr [esi])._SS
- mov edi, (IA32_REGS ptr [esi])._ESP
- sub edi, ecx ; reserve space on realmode stack
- push edi ; save stack offset
- imul eax, edx, 16 ; eax <- edx * 16
- add edi, eax ; edi <- linear address of 16-bit stack
- rep movsb ; copy RegSet
- mov esi, edx ; esi <- 16-bit stack segment
- pop ebx ; ebx <- 16-bit stack offset
- mov edi, [esp + 40] ; edi <- realmode patch
- push cs ; save CS segment selector
- push offset @BackToThunk ; offset to back from real mode
- mov eax, offset @16Return
- stosd
- xor eax, eax
- stosw ; set CS base to 0
- mov eax, esp
- stosd
- mov eax, ss
- stosd
- mov eax, cr0
- mov ecx, eax ; ecx <- CR0
- and ecx, 7ffffffeh ; clear PE, PG bits
- stosd
- mov eax, cr4
- mov ebp, eax
- and ebp, 300h ; clear all but PCE and OSFXSR bits
- stosd
- sidt fword ptr [esp + 44] ; use parameter space to save IDTR
- sgdt fword ptr [edi]
- lidt _16Idtr
- push 10h
- pop eax
- push 8
- push offset @16Start
- lgdt _16Gdtr
- retf
-@16Start: ; 16-bit starts here
- mov ss, eax ; set SS to be a 16-bit segment
- mov cr0, ecx
- mov cr4, ebp
- mov ss, esi ; set up 16-bit stack
- mov sp, bx ; mov esp, ebx actually
- popaw ; popad actually
- pop ds
- pop es
- pop fs
- pop gs
- add sp, 4 ; skip _EFLAGS
+ .const
+
+m16Size DW offset InternalAsmThunk16 - offset m16Start
+mThunk16Attr DW offset _ThunkAttr - offset m16Start
+m16Gdt DW offset _NullSegDesc - offset m16Start
+m16GdtrBase DW offset _16GdtrBase - offset m16Start
+mTransition DW offset _EntryPoint - offset m16Start
+
+ .code
+
+m16Start LABEL BYTE
+
+SavedGdt LABEL FWORD
+ DW ?
+ DD ?
+
+_BackFromUserCode PROC
+ push ss
+ push cs
DB 66h
- retf ; transfer control to 16-bit code
-@16Return:
+ call @Base ; push eip
+@Base:
pushf ; pushfd actually
+ cli ; disable interrupts
push gs
push fs
push es
push ds
pushaw ; pushad actually
- DB 67h, 66h
- lds esi, fword ptr (IA32_REGS ptr [esp])._EIP
- DB 67h, 66h
- mov eax, [esi + 12]
- mov cr4, eax ; restore CR4
- DB 67h, 66h
- lgdt fword ptr [esi + 16]
- DB 67h, 66h
- mov eax, [esi + 8]
- mov cr0, eax ; restore CR0
- xor ax, ax ; xor eax, eax actually
+ DB 66h, 0bah ; mov edx, imm32
+_ThunkAttr DD ?
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15
+ jz @1
+ mov eax, 15cd2401h ; mov ax, 2401h & int 15h
+ cli ; disable interrupts
+ jnc @2
+@1:
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL
+ jz @2
+ in al, 92h
+ or al, 2
+ out 92h, al ; deactivate A20M#
+@2:
mov eax, ss
DB 67h
- mov dword ptr (IA32_REGS ptr [esp])._SS, eax
- shl ax, 4 ; shl eax, 4 actually
- add ax, sp ; add eax, esp actually
- add sp, sizeof (IA32_REGS) ; add esp, sizeof (IA32_REGS)
- DB 67h, 66h
- mov dword ptr (IA32_REGS ptr [esp - sizeof (IA32_REGS)])._ESP, esp
- DB 67h, 66h
- lss esp, fword ptr [esi] ; restore protected mode stack
+ lea bp, [esp + sizeof (IA32_REGS)]
+ mov word ptr (IA32_REGS ptr [esi - sizeof (IA32_REGS)])._ESP, bp
+ mov ebx, (IA32_REGS ptr [esi - sizeof (IA32_REGS)])._EIP
+ shl ax, 4 ; shl eax, 4
+ add bp, ax ; add ebp, eax
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr4 DD ?
+ mov cr4, eax
+ DB 66h
+ lgdt fword ptr cs:[edi + (offset SavedGdt - offset @Base)]
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr0 DD ?
+ mov cr0, eax
+ DB 0b8h ; mov ax, imm16
+SavedSs DW ?
+ mov ss, eax
+ DB 66h, 0bch ; mov esp, imm32
+SavedEsp DD ?
DB 66h
- retf ; go back to protected mode
-@BackToThunk:
+ retf ; return to protected mode
+_BackFromUserCode ENDP
+
+_EntryPoint DD offset _ToUserCode - offset m16Start
+ DW 8h
+_16Idtr FWORD (1 SHL 10) - 1
+_16Gdtr LABEL FWORD
+ DW offset GdtEnd - offset _NullSegDesc - 1
+_16GdtrBase DD offset _NullSegDesc
+
+_ToUserCode PROC
+ mov edx, ss
+ mov ss, ecx ; set new segment selectors
+ mov ds, ecx
+ mov es, ecx
+ mov fs, ecx
+ mov gs, ecx
+ mov cr0, eax
+ mov cr4, ebp ; real mode starts at next instruction
+ mov ss, esi ; set up 16-bit stack segment
+ xchg sp, bx ; set up 16-bit stack pointer
+ DB 66h
+ call @Base ; push eip
+@Base:
+ pop bp ; ebp <- offset @Base
+ mov cs:[esi + (offset SavedSs - offset @Base)], edx
+ mov cs:[esi + (offset SavedEsp - offset @Base)], bx
+ DB 66h
+ lidt fword ptr cs:[esi + (offset _16Idtr - offset @Base)]
+ popaw ; popad actually
+ pop ds
+ pop es
+ pop fs
+ pop gs
+ popf ; popfd
+ DB 66h
+ retf ; transfer control to user code
+_ToUserCode ENDP
+
+_NullSegDesc DQ 0
+_16CsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 9bh
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+_16DsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 93h
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+GdtEnd LABEL QWORD
+
+;
+; @param RegSet Pointer to a IA32_DWORD_REGS structure
+; @param Transition Pointer to the transition code
+; @return The address of the 16-bit stack after returning from user code
+;
+InternalAsmThunk16 PROC USES ebp ebx esi edi ds es fs gs
+ mov esi, [esp + 36] ; esi <- RegSet
+ movzx edx, (IA32_REGS ptr [esi])._SS
+ mov edi, (IA32_REGS ptr [esi])._ESP
+ add edi, - (sizeof (IA32_REGS) + 4) ; reserve stack space
+ mov ebx, edi ; ebx <- stack offset
+ imul eax, edx, 16 ; eax <- edx * 16
+ push sizeof (IA32_REGS) / 4
+ add edi, eax ; edi <- linear address of 16-bit stack
+ pop ecx
+ rep movsd ; copy RegSet
+ mov eax, [esp + 40] ; eax <- address of transition code
+ mov esi, edx ; esi <- 16-bit stack segment
+ lea edx, [eax + (offset SavedCr0 - offset m16Start)]
+ mov ecx, eax
+ and ecx, 0fh
+ shl eax, 12
+ lea ecx, [ecx + (offset _BackFromUserCode - offset m16Start)]
+ mov ax, cx
+ stosd ; [edi] <- return address of user code
+ sgdt fword ptr [edx + (offset SavedGdt - offset SavedCr0)]
+ sidt fword ptr [esp + 36] ; save IDT stack in argument space
+ mov eax, cr0
+ mov [edx], eax ; save CR0 in SavedCr0
+ and eax, 7ffffffeh ; clear PE, PG bits
+ mov ebp, cr4
+ mov [edx + (offset SavedCr4 - offset SavedCr0)], ebp
+ and ebp, 300h ; clear all but PCE and OSFXSR bits
+ push 10h
+ pop ecx ; ecx <- selector for data segments
+ lgdt fword ptr [edx + (offset _16Gdtr - offset SavedCr0)]
+ call fword ptr [edx + (offset _EntryPoint - offset SavedCr0)]
lidt fword ptr [esp + 36] ; restore protected mode IDTR
+ lea eax, [ebp - sizeof (IA32_REGS)]
ret
InternalAsmThunk16 ENDP
diff --git a/MdePkg/Library/BaseLib/Ipf/CpuBreakpoint.c b/MdePkg/Library/BaseLib/Ipf/CpuBreakpoint.c index 987fc9c..7923e92 100644 --- a/MdePkg/Library/BaseLib/Ipf/CpuBreakpoint.c +++ b/MdePkg/Library/BaseLib/Ipf/CpuBreakpoint.c @@ -99,3 +99,21 @@ GetInterruptState ( {
return FALSE;
}
+
+/**
+ Enables CPU interrupts for the smallest window required to capture any
+ pending interrupts.
+
+ Enables CPU interrupts for the smallest window required to capture any
+ pending interrupts.
+
+**/
+VOID
+EFIAPI
+EnableDisableInterrupts (
+ VOID
+ )
+{
+ EnableInterrupts ();
+ DisableInterrupts ();
+}
diff --git a/MdePkg/Library/BaseLib/Ipf/CpuPause.s b/MdePkg/Library/BaseLib/Ipf/CpuPause.s new file mode 100644 index 0000000..f52692f --- /dev/null +++ b/MdePkg/Library/BaseLib/Ipf/CpuPause.s @@ -0,0 +1,25 @@ +/// @file
+/// CpuPause() function for Itanium-based architecture.
+///
+/// Copyright (c) 2006, Intel Corporation
+/// All rights reserved. This program and the accompanying materials
+/// are licensed and made available under the terms and conditions of the BSD License
+/// which accompanies this distribution. The full text of the license may be found at
+/// http://opensource.org/licenses/bsd-license.php
+///
+/// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+///
+/// Module Name: CpuPause.s
+///
+///
+
+.auto
+.text
+
+.proc CpuPause
+.type CpuPause, @function
+CpuPause::
+ hint @pause
+ br.ret.sptk.many b0
+.endp
diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.asm b/MdePkg/Library/BaseLib/X64/Thunk16.asm index f3e8084..15aaa80 100644 --- a/MdePkg/Library/BaseLib/X64/Thunk16.asm +++ b/MdePkg/Library/BaseLib/X64/Thunk16.asm @@ -19,34 +19,16 @@ ;
;------------------------------------------------------------------------------
- .data
+EXTERNDEF m16Start:BYTE
+EXTERNDEF m16Size:WORD
+EXTERNDEF mThunk16Attr:WORD
+EXTERNDEF m16Gdt:WORD
+EXTERNDEF m16GdtrBase:WORD
+EXTERNDEF mTransition:WORD
-NullSegSel DQ 0
-_16CsSegSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 9bh
- DB 8fh ; 16-bit segment
- DB 0
-_16BitDsSel LABEL QWORD
- DW -1
- DW 0
- DB 0
- DB 93h
- DB 8fh ; 16-bit segment
- DB 0
-GdtEnd LABEL QWORD
-
- .const
-
-_16Gdtr LABEL FWORD
- DW offset GdtEnd - offset NullSegSel - 1
- DQ offset NullSegSel
-
-_16Idtr FWORD (1 SHL 10) - 1
-
- .code
+THUNK_ATTRIBUTE_BIG_REAL_MODE EQU 1
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15 EQU 2
+THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL EQU 4
IA32_REGS STRUC 4t
_EDI DD ?
@@ -61,128 +43,192 @@ _DS DW ? _ES DW ?
_FS DW ?
_GS DW ?
-_RFLAGS DQ ?
+_EFLAGS DQ ?
_EIP DD ?
_CS DW ?
_SS DW ?
IA32_REGS ENDS
-InternalAsmThunk16 PROC USES rbp rbx rsi rdi r12 r13 r14 r15
- mov eax, ds
- push rax
- mov eax, es
- push rax
- push fs
- push gs
- mov rsi, rcx ; rsi <- RegSet
- push sizeof (IA32_REGS)
- pop rcx
- movzx r8, (IA32_REGS ptr [rsi])._SS
- xor rdi, rdi
- mov edi, (IA32_REGS ptr [rsi])._ESP
- sub rdi, rcx ; reserve space on realmode stack
- push rdi ; save stack offset
- imul rax, r8, 16
- add rdi, rax ; rdi <- linear address of 16-bit stack
- rep movsb ; copy RegSet
- mov rsi, r8 ; si <- 16-bit stack segment
- pop rbx ; rbx <- 16-bit stack offset
- mov rdi, rdx ; rdi <- realmode patch
- lea eax, @BackToThunk ; rax <- address to back from real mode
- push rax ; use in a far return
- mov eax, cs
- mov [rsp + 4], eax ; save CS
- lea eax, @16Return ; thus @Return must < 4GB
- stosd ; set ret address offset
- xor eax, eax
- stosw ; set ret CS base to 0
- mov eax, esp
- stosd ; rsp must < 4GB
- mov eax, ss
- stosd
- mov rax, cr0
- mov ecx, eax ; ecx <- CR0
- and ecx, 7ffffffeh ; clear PE, PG bits
- stosd
- mov rax, cr4
- mov ebp, eax
- and ebp, 300h ; clear all but PCE and OSFXSR bits
- stosd
- sidt fword ptr [rsp + 70h] ; use parameter space to save IDTR
- sgdt fword ptr [rdi]
- lea edi, _16Idtr
- lea eax, @16Start ; rax <- seg:offset of @16Start
- push rax
- mov dword ptr [rsp + 4], 8
- push 10h
- pop rax ; rax <- 10h as dataseg selector
- lgdt _16Gdtr
- retf
-@16Start: ; 16-bit starts here
- mov ss, eax ; set SS to be a 16-bit segment
- mov cr0, rcx ; disable protected mode
- mov cr4, rbp
- DB 66h
- mov ecx, 0c0000080h
- rdmsr
- and ah, NOT 1 ; clear LME
- wrmsr
- mov ss, esi ; set up 16-bit stack
- mov sp, bx ; mov esp, ebx actually
- lidt fword ptr [edi]
- DB 66h, 61h ; popad
- DB 1fh ; pop ds
- DB 7 ; pop es
- pop fs
- pop gs
- add sp, 8 ; skip _RFLAGS
+ .const
+
+m16Size DW offset InternalAsmThunk16 - offset m16Start
+mThunk16Attr DW offset _ThunkAttr - offset m16Start
+m16Gdt DW offset _NullSegDesc - offset m16Start
+m16GdtrBase DW offset _16GdtrBase - offset m16Start
+mTransition DW offset _EntryPoint - offset m16Start
+
+ .code
+
+m16Start LABEL BYTE
+
+SavedGdt LABEL FWORD
+ DW ?
+ DQ ?
+
+_BackFromUserCode PROC
+ DB 16h ; push ss
+ DB 0eh ; push cs
DB 66h
- retf ; transfer control to 16-bit code
-@16Return:
+ call @Base ; push eip
+@Base:
DB 66h
- push 0 ; high order 32 bits of rflags
+ push 0 ; reserved high order 32 bits of EFlags
pushf ; pushfd actually
+ cli ; disable interrupts
push gs
push fs
DB 6 ; push es
DB 1eh ; push ds
DB 66h, 60h ; pushad
- DB 67h, 66h, 0c5h, 74h, 24h, 30h ; lds esi, [esp + 12*4]
- DB 66h
- mov eax, [esi + 12]
- mov cr4, rax ; restore CR4
- DB 66h
- lgdt fword ptr [esi + 16]
+ DB 66h, 0bah ; mov edx, imm32
+_ThunkAttr DD ?
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15
+ jz @1
+ mov eax, 15cd2401h ; mov ax, 2401h & int 15h
+ cli ; disable interrupts
+ jnc @2
+@1:
+ test dl, THUNK_ATTRIBUTE_DISABLE_A20_MASK_KBD_CTRL
+ jz @2
+ in al, 92h
+ or al, 2
+ out 92h, al ; deactivate A20M#
+@2:
+ mov eax, ss
+ lea bp, [esp + sizeof (IA32_REGS)]
+ mov word ptr (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._ESP, bp
+ mov ebx, (IA32_REGS ptr [rsi - sizeof (IA32_REGS)])._EIP
+ shl ax, 4 ; shl eax, 4
+ add bp, ax ; add ebp, eax
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr4 DD ?
+ mov cr4, rax
+ DB 66h, 2eh
+ lgdt fword ptr [rdi + (offset SavedGdt - offset @Base)]
DB 66h
mov ecx, 0c0000080h
rdmsr
- or ah, 1 ; set LME
+ or ah, 1
wrmsr
+ DB 66h, 0b8h ; mov eax, imm32
+SavedCr0 DD ?
+ mov cr0, rax
+ DB 0b8h ; mov ax, imm16
+SavedSs DW ?
+ mov ss, eax
+ DB 66h, 0bch ; mov esp, imm32
+SavedEsp DD ?
DB 66h
- mov eax, [esi + 8]
- mov cr0, rax ; restore CR0
- xor ax, ax ; xor eax, eax actually
- mov eax, ss
- mov dword ptr (IA32_REGS ptr [esp])._SS, eax
- shl ax, 4 ; shl eax, 4 actually
- add ax, sp ; add eax, esp actually
- add sp, sizeof (IA32_REGS) ; add esp, sizeof (IA32_REGS)
+ retf ; return to protected mode
+_BackFromUserCode ENDP
+
+_EntryPoint DD offset _ToUserCode - offset m16Start
+ DW 8h
+_16Gdtr LABEL FWORD
+ DW offset GdtEnd - offset _NullSegDesc - 1
+_16GdtrBase DQ offset _NullSegDesc
+_16Idtr FWORD (1 SHL 10) - 1
+
+_ToUserCode PROC
+ mov edi, ss
+ mov ss, edx ; set new segment selectors
+ mov ds, edx
+ mov es, edx
+ mov fs, edx
+ mov gs, edx
DB 66h
- mov dword ptr (IA32_REGS ptr [esp - sizeof (IA32_REGS)])._ESP, esp
+ mov ecx, 0c0000080h
+ mov cr0, rax ; real mode starts at next instruction
+ rdmsr
+ and ah, NOT 1
+ wrmsr
+ mov cr4, rbp
+ mov ss, esi ; set up 16-bit stack segment
+ xchg sp, bx ; set up 16-bit stack pointer
DB 66h
- lss esp, fword ptr [esi] ; restore protected mode stack
+ call @Base ; push eip
+@Base:
+ pop bp ; ebp <- offset @Base
+ DB 2eh ; cs:
+ mov [rsi + (offset SavedSs - offset @Base)], edi
+ DB 2eh ; cs:
+ mov [rsi + (offset SavedEsp - offset @Base)], bx
+ DB 66h, 2eh ; CS and operand size override
+ lidt fword ptr [rsi + (offset _16Idtr - offset @Base)]
+ DB 66h, 61h ; popad
+ DB 1fh ; pop ds
+ DB 07h ; pop es
+ pop fs
+ pop gs
+ popf ; popfd
+ lea sp, [esp + 4] ; skip high order 32 bits of EFlags
DB 66h
- retf ; go back to protected mode
-@BackToThunk:
- lidt fword ptr [rsp + 68h] ; restore protected mode IDTR
- shl rax, 32
- shr rax, 32 ; clear high order 32 bits of RAX
+ retf ; transfer control to user code
+_ToUserCode ENDP
+
+_NullSegDesc DQ 0
+_16CsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 9bh
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+_16DsDesc LABEL QWORD
+ DW -1
+ DW 0
+ DB 0
+ DB 93h
+ DB 8fh ; 16-bit segment, 4GB limit
+ DB 0
+GdtEnd LABEL QWORD
+
+;
+; @param RegSet Pointer to a IA32_DWORD_REGS structure
+; @param Transition Pointer to the transition code
+; @return The address of the 16-bit stack after returning from user code
+;
+InternalAsmThunk16 PROC USES rbp rbx rsi rdi
+ mov r10d, ds
+ mov r11d, es
+ push fs
+ push gs
+ mov rsi, rcx
+ movzx r8d, (IA32_REGS ptr [rsi])._SS
+ mov edi, (IA32_REGS ptr [rsi])._ESP
+ lea rdi, [edi - (sizeof (IA32_REGS) + 4)]
+ imul eax, r8d, 16 ; eax <- r8d(stack segment) * 16
+ mov ebx, edi ; ebx <- stack offset for 16-bit code
+ push sizeof (IA32_REGS) / 4
+ add edi, eax ; edi <- linear address of 16-bit stack
+ pop rcx
+ rep movsd ; copy RegSet
+ lea ecx, [rdx + (offset SavedCr4 - offset m16Start)]
+ mov eax, edx ; eax <- transition code address
+ and edx, 0fh
+ shl eax, 12
+ lea edx, [rdx + (offset _BackFromUserCode - offset m16Start)]
+ mov ax, dx
+ stosd ; [edi] <- return address of user code
+ sgdt fword ptr [rcx + (offset SavedGdt - offset SavedCr4)]
+ sidt fword ptr [rsp + 38h] ; save IDT stack in argument space
+ mov rax, cr0
+ mov [rcx + (offset SavedCr0 - offset SavedCr4)], eax
+ and eax, 7ffffffeh ; clear PE, PG bits
+ mov rbp, cr4
+ mov [rcx], ebp ; save CR4 in SavedCr4
+ and ebp, 300h ; clear all but PCE and OSFXSR bits
+ mov esi, r8d ; esi <- 16-bit stack segment
+ push 10h
+ pop rdx ; rdx <- selector for data segments
+ lgdt fword ptr [rcx + (offset _16Gdtr - offset SavedCr4)]
+ call fword ptr [rcx + (offset _EntryPoint - offset SavedCr4)]
+ lidt fword ptr [rsp + 38h] ; restore protected mode IDTR
+ lea eax, [rbp - sizeof (IA32_REGS)]
pop gs
pop fs
- pop rcx
- mov es, ecx
- pop rcx
- mov ds, ecx
+ mov es, r11d
+ mov ds, r10d
ret
InternalAsmThunk16 ENDP
diff --git a/MdePkg/Library/BaseLib/x86Thunk.c b/MdePkg/Library/BaseLib/x86Thunk.c index 8cb5f4f..7045924 100644 --- a/MdePkg/Library/BaseLib/x86Thunk.c +++ b/MdePkg/Library/BaseLib/x86Thunk.c @@ -14,6 +14,35 @@ **/
+//
+// Byte packed structure for a segment descriptor in a GDT/LDT
+//
+typedef union {
+ struct {
+ UINT32 LimitLow:16;
+ UINT32 BaseLow:16;
+ UINT32 BaseMid:8;
+ UINT32 Type:4;
+ UINT32 S:1;
+ UINT32 DPL:2;
+ UINT32 P:1;
+ UINT32 LimitHigh:4;
+ UINT32 AVL:1;
+ UINT32 L:1;
+ UINT32 DB:1;
+ UINT32 G:1;
+ UINT32 BaseHigh:8;
+ } Bits;
+ UINT64 Uint64;
+} IA32_SEGMENT_DESCRIPTOR;
+
+extern CONST UINT8 m16Start;
+extern CONST UINT16 m16Size;
+extern CONST UINT16 mThunk16Attr;
+extern CONST UINT16 m16Gdt;
+extern CONST UINT16 m16GdtrBase;
+extern CONST UINT16 mTransition;
+
/**
Invokes 16-bit code in big real mode and returns the updated register set.
@@ -22,7 +51,7 @@ on the real mode stack and the starting address of the save area is returned.
@param RegisterSet Values of registers before invocation of 16-bit code.
- @param Patch Pointer to the area following the 16-bit code.
+ @param Transition Pointer to the transition code under 1MB.
@return The pointer to a IA32_REGISTER_SET structure containing the updated
register values.
@@ -31,10 +60,45 @@ IA32_REGISTER_SET *
InternalAsmThunk16 (
IN IA32_REGISTER_SET *RegisterSet,
- IN OUT VOID *Patch
+ IN OUT VOID *Transition
);
/**
+ Retrieves the properties for 16-bit thunk functions.
+
+ Computes the size of the buffer and stack below 1MB required to use the
+ AsmPrepareThunk16(), AsmThunk16() and AsmPrepareAndThunk16() functions. This
+ buffer size is returned in RealModeBufferSize, and the stack size is returned
+ in ExtraStackSize. If parameters are passed to the 16-bit real mode code,
+ then the actual minimum stack size is ExtraStackSize plus the maximum number
+ of bytes that need to be passed to the 16-bit real mode code.
+
+ If RealModeBufferSize is NULL, then ASSERT().
+ If ExtraStackSize is NULL, then ASSERT().
+
+ @param RealModeBufferSize A pointer to the size of the buffer below 1MB
+ required to use the 16-bit thunk functions.
+ @param ExtraStackSize A pointer to the extra size of stack below 1MB
+ that the 16-bit thunk functions require for
+ temporary storage in the transition to and from
+ 16-bit real mode.
+
+**/
+VOID
+EFIAPI
+AsmGetThunk16Properties (
+ OUT UINT32 *RealModeBufferSize,
+ OUT UINT32 *ExtraStackSize
+ )
+{
+ ASSERT (RealModeBufferSize != NULL);
+ ASSERT (ExtraStackSize != NULL);
+
+ *RealModeBufferSize = m16Size;
+ *ExtraStackSize = sizeof (IA32_DWORD_REGS) + 8;
+}
+
+/**
Prepares all structures a code required to use AsmThunk16().
Prepares all structures and code required to use AsmThunk16().
@@ -51,7 +115,64 @@ AsmPrepareThunk16 ( OUT THUNK_CONTEXT *ThunkContext
)
{
+ IA32_SEGMENT_DESCRIPTOR *RealModeGdt;
+
ASSERT (ThunkContext != NULL);
+ ASSERT ((UINTN)ThunkContext->RealModeBuffer < 0x100000);
+ ASSERT (ThunkContext->RealModeBufferSize >= m16Size);
+ ASSERT ((UINTN)ThunkContext->RealModeBuffer + m16Size <= 0x100000);
+ ASSERT (((UINTN)ThunkContext->RealModeBuffer & 0x0f) == 0);
+
+ CopyMem (ThunkContext->RealModeBuffer, &m16Start, m16Size);
+
+ //
+ // Point RealModeGdt to the GDT to be used in transition
+ //
+ // RealModeGdt[0]: Reserved as NULL descriptor
+ // RealModeGdt[1]: Code Segment
+ // RealModeGdt[2]: Data Segment
+ // RealModeGdt[3]: Call Gate
+ //
+ RealModeGdt = (IA32_SEGMENT_DESCRIPTOR*)(
+ (UINTN)ThunkContext->RealModeBuffer + m16Gdt);
+
+ //
+ // Update Code & Data Segment Descriptor
+ //
+ RealModeGdt[1].Bits.BaseLow =
+ (UINT32)(UINTN)ThunkContext->RealModeBuffer & ~0xf;
+ RealModeGdt[1].Bits.BaseMid =
+ (UINT32)(UINTN)ThunkContext->RealModeBuffer >> 16;
+
+ //
+ // Update transition code entry point offset
+ //
+ *(UINT32*)((UINTN)ThunkContext->RealModeBuffer + mTransition) +=
+ (UINT32)(UINTN)ThunkContext->RealModeBuffer & 0xf;
+
+ //
+ // Update Segment Limits for both Code and Data Segment Descriptors
+ //
+ if ((ThunkContext->ThunkAttributes & THUNK_ATTRIBUTE_BIG_REAL_MODE) == 0) {
+ //
+ // Set segment limits to 64KB
+ //
+ RealModeGdt[1].Bits.LimitHigh = 0;
+ RealModeGdt[1].Bits.G = 0;
+ RealModeGdt[2].Bits.LimitHigh = 0;
+ RealModeGdt[2].Bits.G = 0;
+ }
+
+ //
+ // Update GDTBASE for this thunk context
+ //
+ *(VOID**)((UINTN)ThunkContext->RealModeBuffer + m16GdtrBase) = RealModeGdt;
+
+ //
+ // Update Thunk Attributes
+ //
+ *(UINT32*)((UINTN)ThunkContext->RealModeBuffer + mThunk16Attr) =
+ ThunkContext->ThunkAttributes;
}
/**
@@ -74,28 +195,20 @@ AsmThunk16 ( IN OUT THUNK_CONTEXT *ThunkContext
)
{
- UINT16 *Patch;
+ IA32_REGISTER_SET *UpdatedRegs;
ASSERT (ThunkContext != NULL);
+ ASSERT ((UINTN)ThunkContext->RealModeBuffer < 0x100000);
+ ASSERT (ThunkContext->RealModeBufferSize >= m16Size);
+ ASSERT ((UINTN)ThunkContext->RealModeBuffer + m16Size <= 0x100000);
+ ASSERT (((UINTN)ThunkContext->RealModeBuffer & 0x0f) == 0);
- Patch = (UINT16*)(
- (UINTN)ThunkContext->RealModeCode +
- ThunkContext->RealModeCodeSize
- );
+ UpdatedRegs = InternalAsmThunk16 (
+ ThunkContext->RealModeState,
+ ThunkContext->RealModeBuffer
+ );
- //
- // 0x9a66 is the OpCode of far call with an operand size override.
- //
- *Patch = 0x9a66;
-
- //
- // CopyMem() here copies the updated register values back to RealModeState
- //
- CopyMem (
- &ThunkContext->RealModeState,
- InternalAsmThunk16 (&ThunkContext->RealModeState, Patch + 1),
- sizeof (ThunkContext->RealModeState)
- );
+ CopyMem (ThunkContext->RealModeState, UpdatedRegs, sizeof (*UpdatedRegs));
}
/**
|