Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /****************************************************************************** |
2 | * | |
3 | * Module Name: tbxfroot - Find the root ACPI table (RSDT) | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
25f044e6 | 8 | * Copyright (C) 2000 - 2013, Intel Corp. |
1da177e4 LT |
9 | * All rights reserved. |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * 1. Redistributions of source code must retain the above copyright | |
15 | * notice, this list of conditions, and the following disclaimer, | |
16 | * without modification. | |
17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer | |
18 | * substantially similar to the "NO WARRANTY" disclaimer below | |
19 | * ("Disclaimer") and any redistribution must be conditioned upon | |
20 | * including a substantially similar Disclaimer requirement for further | |
21 | * binary redistribution. | |
22 | * 3. Neither the names of the above-listed copyright holders nor the names | |
23 | * of any contributors may be used to endorse or promote products derived | |
24 | * from this software without specific prior written permission. | |
25 | * | |
26 | * Alternatively, this software may be distributed under the terms of the | |
27 | * GNU General Public License ("GPL") version 2 as published by the Free | |
28 | * Software Foundation. | |
29 | * | |
30 | * NO WARRANTY | |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR | |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
41 | * POSSIBILITY OF SUCH DAMAGES. | |
42 | */ | |
43 | ||
1da177e4 | 44 | #include <acpi/acpi.h> |
e2f7a777 LB |
45 | #include "accommon.h" |
46 | #include "actables.h" | |
1da177e4 | 47 | |
1da177e4 | 48 | #define _COMPONENT ACPI_TABLES |
4be44fcd | 49 | ACPI_MODULE_NAME("tbxfroot") |
1da177e4 | 50 | |
f9f4601f RM |
51 | /******************************************************************************* |
52 | * | |
53 | * FUNCTION: acpi_tb_validate_rsdp | |
54 | * | |
ba494bee | 55 | * PARAMETERS: rsdp - Pointer to unvalidated RSDP |
f9f4601f RM |
56 | * |
57 | * RETURN: Status | |
58 | * | |
59 | * DESCRIPTION: Validate the RSDP (ptr) | |
60 | * | |
61 | ******************************************************************************/ | |
38f7c5a1 | 62 | acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp) |
f9f4601f | 63 | { |
f9f4601f RM |
64 | |
65 | /* | |
f3d2e786 BM |
66 | * The signature and checksum must both be correct |
67 | * | |
68 | * Note: Sometimes there exists more than one RSDP in memory; the valid | |
69 | * RSDP has a valid checksum, all others have an invalid checksum. | |
f9f4601f | 70 | */ |
38f7c5a1 | 71 | if (ACPI_STRNCMP((char *)rsdp->signature, ACPI_SIG_RSDP, |
ec41f193 | 72 | sizeof(ACPI_SIG_RSDP) - 1) != 0) { |
52fc0b02 | 73 | |
f9f4601f RM |
74 | /* Nope, BAD Signature */ |
75 | ||
76 | return (AE_BAD_SIGNATURE); | |
77 | } | |
78 | ||
79 | /* Check the standard checksum */ | |
80 | ||
f3d2e786 | 81 | if (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) { |
f9f4601f RM |
82 | return (AE_BAD_CHECKSUM); |
83 | } | |
84 | ||
85 | /* Check extended checksum if table version >= 2 */ | |
86 | ||
87 | if ((rsdp->revision >= 2) && | |
f3d2e786 | 88 | (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) { |
f9f4601f RM |
89 | return (AE_BAD_CHECKSUM); |
90 | } | |
91 | ||
92 | return (AE_OK); | |
93 | } | |
94 | ||
1da177e4 LT |
95 | /******************************************************************************* |
96 | * | |
239665a3 | 97 | * FUNCTION: acpi_find_root_pointer |
1da177e4 | 98 | * |
f3d2e786 | 99 | * PARAMETERS: table_address - Where the table pointer is returned |
1da177e4 | 100 | * |
f3d2e786 | 101 | * RETURN: Status, RSDP physical address |
1da177e4 | 102 | * |
ba494bee | 103 | * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor |
73a3090a | 104 | * pointer structure. If it is found, set *RSDP to point to it. |
1da177e4 | 105 | * |
ba494bee | 106 | * NOTE1: The RSDP must be either in the first 1K of the Extended |
f3d2e786 BM |
107 | * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) |
108 | * Only a 32-bit physical address is necessary. | |
1da177e4 | 109 | * |
f3d2e786 BM |
110 | * NOTE2: This function is always available, regardless of the |
111 | * initialization state of the rest of ACPI. | |
1da177e4 LT |
112 | * |
113 | ******************************************************************************/ | |
114 | ||
67a119f9 | 115 | acpi_status acpi_find_root_pointer(acpi_size *table_address) |
1da177e4 | 116 | { |
f3d2e786 BM |
117 | u8 *table_ptr; |
118 | u8 *mem_rover; | |
119 | u32 physical_address; | |
1da177e4 | 120 | |
f3d2e786 | 121 | ACPI_FUNCTION_TRACE(acpi_find_root_pointer); |
1da177e4 | 122 | |
f3d2e786 | 123 | /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ |
1da177e4 | 124 | |
f3d2e786 BM |
125 | table_ptr = acpi_os_map_memory((acpi_physical_address) |
126 | ACPI_EBDA_PTR_LOCATION, | |
127 | ACPI_EBDA_PTR_LENGTH); | |
128 | if (!table_ptr) { | |
129 | ACPI_ERROR((AE_INFO, | |
f6a22b0b | 130 | "Could not map memory at 0x%8.8X for length %u", |
f3d2e786 | 131 | ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); |
1da177e4 | 132 | |
4be44fcd | 133 | return_ACPI_STATUS(AE_NO_MEMORY); |
1da177e4 LT |
134 | } |
135 | ||
f3d2e786 | 136 | ACPI_MOVE_16_TO_32(&physical_address, table_ptr); |
1da177e4 | 137 | |
f3d2e786 | 138 | /* Convert segment part to physical address */ |
1da177e4 | 139 | |
f3d2e786 BM |
140 | physical_address <<= 4; |
141 | acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH); | |
1da177e4 | 142 | |
f3d2e786 | 143 | /* EBDA present? */ |
1da177e4 | 144 | |
f3d2e786 | 145 | if (physical_address > 0x400) { |
73459f73 | 146 | /* |
f3d2e786 | 147 | * 1b) Search EBDA paragraphs (EBDA is required to be a |
ba494bee | 148 | * minimum of 1K length) |
73459f73 | 149 | */ |
67a119f9 | 150 | table_ptr = acpi_os_map_memory((acpi_physical_address) |
f3d2e786 BM |
151 | physical_address, |
152 | ACPI_EBDA_WINDOW_SIZE); | |
153 | if (!table_ptr) { | |
154 | ACPI_ERROR((AE_INFO, | |
f6a22b0b | 155 | "Could not map memory at 0x%8.8X for length %u", |
f3d2e786 | 156 | physical_address, ACPI_EBDA_WINDOW_SIZE)); |
1da177e4 | 157 | |
f3d2e786 | 158 | return_ACPI_STATUS(AE_NO_MEMORY); |
1da177e4 LT |
159 | } |
160 | ||
f3d2e786 BM |
161 | mem_rover = |
162 | acpi_tb_scan_memory_for_rsdp(table_ptr, | |
163 | ACPI_EBDA_WINDOW_SIZE); | |
164 | acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE); | |
1da177e4 | 165 | |
f3d2e786 | 166 | if (mem_rover) { |
52fc0b02 | 167 | |
f3d2e786 | 168 | /* Return the physical address */ |
1da177e4 | 169 | |
f3d2e786 BM |
170 | physical_address += |
171 | (u32) ACPI_PTR_DIFF(mem_rover, table_ptr); | |
1da177e4 | 172 | |
f3d2e786 BM |
173 | *table_address = physical_address; |
174 | return_ACPI_STATUS(AE_OK); | |
1da177e4 LT |
175 | } |
176 | } | |
177 | ||
f3d2e786 BM |
178 | /* |
179 | * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh | |
180 | */ | |
181 | table_ptr = acpi_os_map_memory((acpi_physical_address) | |
182 | ACPI_HI_RSDP_WINDOW_BASE, | |
183 | ACPI_HI_RSDP_WINDOW_SIZE); | |
1da177e4 | 184 | |
f3d2e786 BM |
185 | if (!table_ptr) { |
186 | ACPI_ERROR((AE_INFO, | |
f6a22b0b | 187 | "Could not map memory at 0x%8.8X for length %u", |
f3d2e786 BM |
188 | ACPI_HI_RSDP_WINDOW_BASE, |
189 | ACPI_HI_RSDP_WINDOW_SIZE)); | |
1da177e4 | 190 | |
f3d2e786 | 191 | return_ACPI_STATUS(AE_NO_MEMORY); |
88ac00f5 | 192 | } |
1da177e4 | 193 | |
f3d2e786 BM |
194 | mem_rover = |
195 | acpi_tb_scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE); | |
196 | acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE); | |
1da177e4 | 197 | |
f3d2e786 | 198 | if (mem_rover) { |
1da177e4 | 199 | |
f3d2e786 | 200 | /* Return the physical address */ |
1da177e4 | 201 | |
f3d2e786 BM |
202 | physical_address = (u32) |
203 | (ACPI_HI_RSDP_WINDOW_BASE + | |
204 | ACPI_PTR_DIFF(mem_rover, table_ptr)); | |
1da177e4 | 205 | |
f3d2e786 BM |
206 | *table_address = physical_address; |
207 | return_ACPI_STATUS(AE_OK); | |
1da177e4 LT |
208 | } |
209 | ||
f3d2e786 BM |
210 | /* A valid RSDP was not found */ |
211 | ||
3b3ea775 | 212 | ACPI_BIOS_ERROR((AE_INFO, "A valid RSDP was not found")); |
f3d2e786 | 213 | return_ACPI_STATUS(AE_NOT_FOUND); |
1da177e4 LT |
214 | } |
215 | ||
1da177e4 LT |
216 | /******************************************************************************* |
217 | * | |
218 | * FUNCTION: acpi_tb_scan_memory_for_rsdp | |
219 | * | |
220 | * PARAMETERS: start_address - Starting pointer for search | |
ba494bee | 221 | * length - Maximum length to search |
1da177e4 LT |
222 | * |
223 | * RETURN: Pointer to the RSDP if found, otherwise NULL. | |
224 | * | |
225 | * DESCRIPTION: Search a block of memory for the RSDP signature | |
226 | * | |
227 | ******************************************************************************/ | |
57987ca2 | 228 | u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length) |
1da177e4 | 229 | { |
4be44fcd LB |
230 | acpi_status status; |
231 | u8 *mem_rover; | |
232 | u8 *end_address; | |
1da177e4 | 233 | |
b229cf92 | 234 | ACPI_FUNCTION_TRACE(tb_scan_memory_for_rsdp); |
1da177e4 LT |
235 | |
236 | end_address = start_address + length; | |
237 | ||
238 | /* Search from given start address for the requested length */ | |
239 | ||
240 | for (mem_rover = start_address; mem_rover < end_address; | |
4be44fcd | 241 | mem_rover += ACPI_RSDP_SCAN_STEP) { |
52fc0b02 | 242 | |
f9f4601f | 243 | /* The RSDP signature and checksum must both be correct */ |
1da177e4 | 244 | |
4be44fcd LB |
245 | status = |
246 | acpi_tb_validate_rsdp(ACPI_CAST_PTR | |
f3d2e786 | 247 | (struct acpi_table_rsdp, mem_rover)); |
4be44fcd | 248 | if (ACPI_SUCCESS(status)) { |
52fc0b02 | 249 | |
f9f4601f | 250 | /* Sig and checksum valid, we have found a real RSDP */ |
1da177e4 | 251 | |
4be44fcd LB |
252 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
253 | "RSDP located at physical address %p\n", | |
254 | mem_rover)); | |
255 | return_PTR(mem_rover); | |
1da177e4 LT |
256 | } |
257 | ||
f9f4601f | 258 | /* No sig match or bad checksum, keep searching */ |
1da177e4 LT |
259 | } |
260 | ||
261 | /* Searched entire block, no RSDP was found */ | |
262 | ||
4be44fcd LB |
263 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, |
264 | "Searched entire block from %p, valid RSDP was not found\n", | |
265 | start_address)); | |
266 | return_PTR(NULL); | |
1da177e4 | 267 | } |