1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
|
/******************************************************************************
*
* Module Name: tbxfroot - Find the root ACPI table (RSDT)
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2010, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"
#define _COMPONENT ACPI_TABLES
ACPI_MODULE_NAME("tbxfroot")
/* Local prototypes */
static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
/*******************************************************************************
*
* FUNCTION: acpi_tb_validate_rsdp
*
* PARAMETERS: Rsdp - Pointer to unvalidated RSDP
*
* RETURN: Status
*
* DESCRIPTION: Validate the RSDP (ptr)
*
******************************************************************************/
static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
{
ACPI_FUNCTION_ENTRY();
/*
* The signature and checksum must both be correct
*
* Note: Sometimes there exists more than one RSDP in memory; the valid
* RSDP has a valid checksum, all others have an invalid checksum.
*/
if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP,
sizeof(ACPI_SIG_RSDP) - 1) != 0) {
/* Nope, BAD Signature */
return (AE_BAD_SIGNATURE);
}
/* Check the standard checksum */
if (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
return (AE_BAD_CHECKSUM);
}
/* Check extended checksum if table version >= 2 */
if ((rsdp->revision >= 2) &&
(acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) {
return (AE_BAD_CHECKSUM);
}
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_find_root_pointer
*
* PARAMETERS: table_address - Where the table pointer is returned
*
* RETURN: Status, RSDP physical address
*
* DESCRIPTION: Search lower 1_mbyte of memory for the root system descriptor
* pointer structure. If it is found, set *RSDP to point to it.
*
* NOTE1: The RSDP must be either in the first 1_k of the Extended
* BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
* Only a 32-bit physical address is necessary.
*
* NOTE2: This function is always available, regardless of the
* initialization state of the rest of ACPI.
*
******************************************************************************/
acpi_status acpi_find_root_pointer(acpi_size *table_address)
{
u8 *table_ptr;
u8 *mem_rover;
u32 physical_address;
ACPI_FUNCTION_TRACE(acpi_find_root_pointer);
/* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
table_ptr = acpi_os_map_memory((acpi_physical_address)
ACPI_EBDA_PTR_LOCATION,
ACPI_EBDA_PTR_LENGTH);
if (!table_ptr) {
ACPI_ERROR((AE_INFO,
"Could not map memory at 0x%8.8X for length %u",
ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
return_ACPI_STATUS(AE_NO_MEMORY);
}
ACPI_MOVE_16_TO_32(&physical_address, table_ptr);
/* Convert segment part to physical address */
physical_address <<= 4;
acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);
/* EBDA present? */
if (physical_address > 0x400) {
/*
* 1b) Search EBDA paragraphs (EBDA is required to be a
* minimum of 1_k length)
*/
table_ptr = acpi_os_map_memory((acpi_physical_address)
physical_address,
ACPI_EBDA_WINDOW_SIZE);
if (!table_ptr) {
ACPI_ERROR((AE_INFO,
"Could not map memory at 0x%8.8X for length %u",
physical_address, ACPI_EBDA_WINDOW_SIZE));
return_ACPI_STATUS(AE_NO_MEMORY);
}
mem_rover =
acpi_tb_scan_memory_for_rsdp(table_ptr,
ACPI_EBDA_WINDOW_SIZE);
acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);
if (mem_rover) {
/* Return the physical address */
physical_address +=
(u32) ACPI_PTR_DIFF(mem_rover, table_ptr);
*table_address = physical_address;
return_ACPI_STATUS(AE_OK);
}
}
/*
* 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
*/
table_ptr = acpi_os_map_memory((acpi_physical_address)
ACPI_HI_RSDP_WINDOW_BASE,
ACPI_HI_RSDP_WINDOW_SIZE);
if (!table_ptr) {
ACPI_ERROR((AE_INFO,
"Could not map memory at 0x%8.8X for length %u",
ACPI_HI_RSDP_WINDOW_BASE,
ACPI_HI_RSDP_WINDOW_SIZE));
return_ACPI_STATUS(AE_NO_MEMORY);
}
mem_rover =
acpi_tb_scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
if (mem_rover) {
/* Return the physical address */
physical_address = (u32)
(ACPI_HI_RSDP_WINDOW_BASE +
ACPI_PTR_DIFF(mem_rover, table_ptr));
*table_address = physical_address;
return_ACPI_STATUS(AE_OK);
}
/* A valid RSDP was not found */
ACPI_ERROR((AE_INFO, "A valid RSDP was not found"));
return_ACPI_STATUS(AE_NOT_FOUND);
}
/*******************************************************************************
*
* FUNCTION: acpi_tb_scan_memory_for_rsdp
*
* PARAMETERS: start_address - Starting pointer for search
* Length - Maximum length to search
*
* RETURN: Pointer to the RSDP if found, otherwise NULL.
*
* DESCRIPTION: Search a block of memory for the RSDP signature
*
******************************************************************************/
static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
{
acpi_status status;
u8 *mem_rover;
u8 *end_address;
ACPI_FUNCTION_TRACE(tb_scan_memory_for_rsdp);
end_address = start_address + length;
/* Search from given start address for the requested length */
for (mem_rover = start_address; mem_rover < end_address;
mem_rover += ACPI_RSDP_SCAN_STEP) {
/* The RSDP signature and checksum must both be correct */
status =
acpi_tb_validate_rsdp(ACPI_CAST_PTR
(struct acpi_table_rsdp, mem_rover));
if (ACPI_SUCCESS(status)) {
/* Sig and checksum valid, we have found a real RSDP */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"RSDP located at physical address %p\n",
mem_rover));
return_PTR(mem_rover);
}
/* No sig match or bad checksum, keep searching */
}
/* Searched entire block, no RSDP was found */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Searched entire block from %p, valid RSDP was not found\n",
start_address));
return_PTR(NULL);
}
|
