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audk/UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm

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UefiCpuPkg/CpuDxe: Add stackless assembly AP entry points The AP startup code simply jumps into this code with the CpuDxe driver without setting up a stack for the processor. Therefore, this code must setup the stack before calling into C code. This is the basic flow: * AP enters CpuDxe driver code (AsmApEntryPoint) without stack - AP grabs a lock - AP sets up stack - AP calls CpuMp.c:ApEntryPointInC - If ApEntryPointInC returns, the lock is freed, and another AP may run - The AP C code may call AsmApDoneWithCommonStack to indicate that the AP is no longer using the stack, and another may therefore proceed to use the stack and then call ApEntryPointInC Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> Reviewed-by: Jeff Fan <jeff.fan@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16347 6f19259b-4bc3-4df7-8a09-765794883524
2014-11-13 19:24:59 +01:00
;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
; 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.
;
;------------------------------------------------------------------------------
UefiCpuPkg: Avoid "error A2085" when DDK3790 tool chain is used The DDK3790 tool chain fails when the PAUSE instruction is assembled: error A2085: instruction or register not accepted in current CPU mode The solution is to use the .686 directive along with the .xmm directive. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Scott Duplichan <scott@notabs.org> Reviewed-by: Jeff Fan <jeff.fan@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17134 6f19259b-4bc3-4df7-8a09-765794883524
2015-04-09 05:09:17 +02:00
.686
.xmm
UefiCpuPkg/CpuDxe: Add stackless assembly AP entry points The AP startup code simply jumps into this code with the CpuDxe driver without setting up a stack for the processor. Therefore, this code must setup the stack before calling into C code. This is the basic flow: * AP enters CpuDxe driver code (AsmApEntryPoint) without stack - AP grabs a lock - AP sets up stack - AP calls CpuMp.c:ApEntryPointInC - If ApEntryPointInC returns, the lock is freed, and another AP may run - The AP C code may call AsmApDoneWithCommonStack to indicate that the AP is no longer using the stack, and another may therefore proceed to use the stack and then call ApEntryPointInC Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> Reviewed-by: Jeff Fan <jeff.fan@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16347 6f19259b-4bc3-4df7-8a09-765794883524
2014-11-13 19:24:59 +01:00
.model flat, C
extern mTopOfApCommonStack:DWORD
extern ApEntryPointInC:PROC
.code
;
; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
;
ApStackLock dd 0
;.code
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; AsmApEntryPoint (
; VOID
; );
;------------------------------------------------------------------------------
AsmApEntryPoint PROC
cli
AsmApEntryPointAcquireLock:
lock bts dword ptr [ApStackLock], 0
pause
jc AsmApEntryPointAcquireLock
mov esp, [mTopOfApCommonStack]
call ApEntryPointInC
cli
lock btc dword ptr [ApStackLock], 0
mov eax, 100h
AsmApEntryPointShareLock:
pause
dec eax
jnz AsmApEntryPointShareLock
jmp AsmApEntryPoint
AsmApEntryPoint ENDP
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; AsmApDoneWithCommonStack (
; VOID
; );
;------------------------------------------------------------------------------
AsmApDoneWithCommonStack PROC PUBLIC
lock btc dword ptr [ApStackLock], 0
ret
AsmApDoneWithCommonStack ENDP
END