c3ac8d7e4dfe750ef1c4bce4d9874a76bdcfa67f
[mirror_edk2.git] / MdePkg / Library / BaseLib / AArch64 / SwitchStack.S
1 //------------------------------------------------------------------------------
2 //
3 // Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
4 // Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
5 // Portions copyright (c) 2011 - 2013, ARM Limited. All rights reserved.<BR>
6 // This program and the accompanying materials
7 // are licensed and made available under the terms and conditions of the BSD License
8 // which accompanies this distribution. The full text of the license may be found at
9 // http://opensource.org/licenses/bsd-license.php.
10 //
11 // THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13 //
14 //------------------------------------------------------------------------------
15
16 .text
17 .align 5
18
19 GCC_ASM_EXPORT(InternalSwitchStackAsm)
20 GCC_ASM_EXPORT(CpuPause)
21
22 /**
23 //
24 // This allows the caller to switch the stack and goes to the new entry point
25 //
26 // @param EntryPoint The pointer to the location to enter
27 // @param Context Parameter to pass in
28 // @param Context2 Parameter2 to pass in
29 // @param NewStack New Location of the stack
30 //
31 // @return Nothing. Goes to the Entry Point passing in the new parameters
32 //
33 VOID
34 EFIAPI
35 InternalSwitchStackAsm (
36 SWITCH_STACK_ENTRY_POINT EntryPoint,
37 VOID *Context,
38 VOID *Context2,
39 VOID *NewStack
40 );
41 **/
42 ASM_PFX(InternalSwitchStackAsm):
43 mov x29, #0
44 mov x30, x0
45 mov sp, x3
46 mov x0, x1
47 mov x1, x2
48 ret
49
50 /**
51 //
52 // Requests CPU to pause for a short period of time.
53 //
54 // Requests CPU to pause for a short period of time. Typically used in MP
55 // systems to prevent memory starvation while waiting for a spin lock.
56 //
57 VOID
58 EFIAPI
59 CpuPause (
60 VOID
61 )
62 **/
63 ASM_PFX(CpuPause):
64 nop
65 nop
66 nop
67 nop
68 nop
69 ret