Changed SwitchStack() to _SwitchStack()
[mirror_edk2.git] / MdePkg / Library / BaseLib / Ipf / SwitchStack.s
CommitLineData
878ddf1f 1//++\r
2// Copyright (c) 2006, Intel Corporation \r
3// All rights reserved. This program and the accompanying materials \r
4// are licensed and made available under the terms and conditions of the BSD License \r
5// which accompanies this distribution. The full text of the license may be found at \r
6// http://opensource.org/licenses/bsd-license.php \r
7// \r
8// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
9// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
10// \r
11// Module Name:\r
12//\r
13// SwitchStack.s\r
14//\r
15// Abstract:\r
16//\r
17// Contains an implementation of a stack switch for the Itanium-based architecture.\r
18//\r
19//\r
20//\r
21// Revision History:\r
22//\r
23//--\r
24\r
25 .file "SwitchStack.s"\r
26\r
27#include "asm.h"\r
28#include "ia_64gen.h"\r
29\r
30// Define hardware RSE Configuration Register\r
31//\r
32// RS Configuration (RSC) bit field positions\r
33\r
34#define RSC_MODE 0\r
35#define RSC_PL 2\r
36#define RSC_BE 4\r
37// RSC bits 5-15 reserved\r
38#define RSC_MBZ0 5\r
39#define RSC_MBZ0_V 0x3ff\r
40#define RSC_LOADRS 16\r
41#define RSC_LOADRS_LEN 14\r
42// RSC bits 30-63 reserved\r
43#define RSC_MBZ1 30\r
44#define RSC_MBZ1_V 0x3ffffffffULL\r
45\r
46// RSC modes\r
47// Lazy\r
48#define RSC_MODE_LY (0x0)\r
49// Store intensive\r
50#define RSC_MODE_SI (0x1)\r
51// Load intensive\r
52#define RSC_MODE_LI (0x2)\r
53// Eager\r
54#define RSC_MODE_EA (0x3)\r
55\r
56// RSC Endian bit values\r
57#define RSC_BE_LITTLE 0\r
58#define RSC_BE_BIG 1\r
59\r
60// RSC while in kernel: enabled, little endian, pl = 0, eager mode\r
61#define RSC_KERNEL ((RSC_MODE_EA<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE))\r
62// Lazy RSC in kernel: enabled, little endian, pl = 0, lazy mode\r
63#define RSC_KERNEL_LAZ ((RSC_MODE_LY<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE))\r
64// RSE disabled: disabled, pl = 0, little endian, eager mode\r
65#define RSC_KERNEL_DISABLED ((RSC_MODE_LY<<RSC_MODE) | (RSC_BE_LITTLE<<RSC_BE))\r
66\r
67\r
68//VOID\r
b4863821 69//_SwitchStack (\r
878ddf1f 70// VOID *ContinuationFunction,\r
71// UINTN Parameter,\r
72// UINTN NewTopOfStack,\r
73// UINTN NewBSPStore OPTIONAL\r
74//)\r
75///*++\r
76//\r
77//Input Arguments\r
78//\r
79// ContinuationFunction - This is a pointer to the PLABEL of the function that should be called once the\r
80// new stack has been created. \r
81// Parameter - The parameter to pass to the continuation function\r
82// NewTopOfStack - This is the new top of the memory stack for ensuing code. This is mandatory and\r
83// should be non-zero\r
84// NewBSPStore - This is the new BSP store for the ensuing code. It is optional on IA-32 and mandatory on Itanium-based platform.\r
85//\r
86//--*/\r
87\r
b4863821 88PROCEDURE_ENTRY(_SwitchStack)\r
878ddf1f 89\r
90 mov r16 = -0x10;;\r
91 and r16 = r34, r16;; // get new stack value in R16, 0 the last nibble.\r
92 mov r15 = r35;; // Get new BspStore into R15\r
93 mov r13 = r32;; // this is a pointer to the PLABEL of the continuation function. \r
94 mov r17 = r33;; // this is the parameter to pass to the continuation function\r
95\r
96 alloc r11=0,0,0,0 // Set 0-size frame\r
97 ;;\r
98 flushrs;;\r
99\r
100 mov r21 = RSC_KERNEL_DISABLED // for rse disable \r
101 ;;\r
102 mov ar.rsc = r21 // turn off RSE \r
103\r
104 add sp = r0, r16;; // transfer to the EFI stack\r
105 mov ar.bspstore = r15 // switch to EFI BSP \r
106 invala // change of ar.bspstore needs invala. \r
107 \r
108 mov r18 = RSC_KERNEL_LAZ // RSC enabled, Lazy mode\r
109 ;;\r
110 mov ar.rsc = r18 // turn rse on, in kernel mode \r
111 ;; \r
112 alloc r11=0,0,1,0;; // alloc 0 outs going to ensuing DXE IPL service\r
113 mov out0 = r17\r
114 ld8 r16 = [r13],8;; // r16 = address of continuation function from the PLABEL\r
115 ld8 gp = [r13] // gp = gp of continuation function from the PLABEL\r
116 mov b6 = r16\r
117 ;;\r
118 br.call.sptk.few b0=b6;; // Call the continuation function\r
119 ;;\r
b4863821 120PROCEDURE_EXIT(_SwitchStack)\r
878ddf1f 121\r
122\r