1 /****************************************************************************** 2 * 3 * Module Name: tbxfroot - Find the root ACPI table (RSDT) 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2013, Intel Corp. 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 44 #define __TBXFROOT_C__ 45 46 #include <contrib/dev/acpica/include/acpi.h> 47 #include <contrib/dev/acpica/include/accommon.h> 48 #include <contrib/dev/acpica/include/actables.h> 49 50 51 #define _COMPONENT ACPI_TABLES 52 ACPI_MODULE_NAME ("tbxfroot") 53 54 55 /******************************************************************************* 56 * 57 * FUNCTION: AcpiTbValidateRsdp 58 * 59 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP 60 * 61 * RETURN: Status 62 * 63 * DESCRIPTION: Validate the RSDP (ptr) 64 * 65 ******************************************************************************/ 66 67 ACPI_STATUS 68 AcpiTbValidateRsdp ( 69 ACPI_TABLE_RSDP *Rsdp) 70 { 71 72 /* 73 * The signature and checksum must both be correct 74 * 75 * Note: Sometimes there exists more than one RSDP in memory; the valid 76 * RSDP has a valid checksum, all others have an invalid checksum. 77 */ 78 if (ACPI_STRNCMP ((char *) Rsdp->Signature, ACPI_SIG_RSDP, 79 sizeof (ACPI_SIG_RSDP)-1) != 0) 80 { 81 /* Nope, BAD Signature */ 82 83 return (AE_BAD_SIGNATURE); 84 } 85 86 /* Check the standard checksum */ 87 88 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) 89 { 90 return (AE_BAD_CHECKSUM); 91 } 92 93 /* Check extended checksum if table version >= 2 */ 94 95 if ((Rsdp->Revision >= 2) && 96 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) 97 { 98 return (AE_BAD_CHECKSUM); 99 } 100 101 return (AE_OK); 102 } 103 104 105 /******************************************************************************* 106 * 107 * FUNCTION: AcpiFindRootPointer 108 * 109 * PARAMETERS: TableAddress - Where the table pointer is returned 110 * 111 * RETURN: Status, RSDP physical address 112 * 113 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor 114 * pointer structure. If it is found, set *RSDP to point to it. 115 * 116 * NOTE1: The RSDP must be either in the first 1K of the Extended 117 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) 118 * Only a 32-bit physical address is necessary. 119 * 120 * NOTE2: This function is always available, regardless of the 121 * initialization state of the rest of ACPI. 122 * 123 ******************************************************************************/ 124 125 ACPI_STATUS 126 AcpiFindRootPointer ( 127 ACPI_SIZE *TableAddress) 128 { 129 UINT8 *TablePtr; 130 UINT8 *MemRover; 131 UINT32 PhysicalAddress; 132 133 134 ACPI_FUNCTION_TRACE (AcpiFindRootPointer); 135 136 137 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ 138 139 TablePtr = AcpiOsMapMemory ( 140 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, 141 ACPI_EBDA_PTR_LENGTH); 142 if (!TablePtr) 143 { 144 ACPI_ERROR ((AE_INFO, 145 "Could not map memory at 0x%8.8X for length %u", 146 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); 147 148 return_ACPI_STATUS (AE_NO_MEMORY); 149 } 150 151 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); 152 153 /* Convert segment part to physical address */ 154 155 PhysicalAddress <<= 4; 156 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); 157 158 /* EBDA present? */ 159 160 if (PhysicalAddress > 0x400) 161 { 162 /* 163 * 1b) Search EBDA paragraphs (EBDA is required to be a 164 * minimum of 1K length) 165 */ 166 TablePtr = AcpiOsMapMemory ( 167 (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, 168 ACPI_EBDA_WINDOW_SIZE); 169 if (!TablePtr) 170 { 171 ACPI_ERROR ((AE_INFO, 172 "Could not map memory at 0x%8.8X for length %u", 173 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); 174 175 return_ACPI_STATUS (AE_NO_MEMORY); 176 } 177 178 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE); 179 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); 180 181 if (MemRover) 182 { 183 /* Return the physical address */ 184 185 PhysicalAddress += (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); 186 187 *TableAddress = PhysicalAddress; 188 return_ACPI_STATUS (AE_OK); 189 } 190 } 191 192 /* 193 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh 194 */ 195 TablePtr = AcpiOsMapMemory ( 196 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, 197 ACPI_HI_RSDP_WINDOW_SIZE); 198 199 if (!TablePtr) 200 { 201 ACPI_ERROR ((AE_INFO, 202 "Could not map memory at 0x%8.8X for length %u", 203 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); 204 205 return_ACPI_STATUS (AE_NO_MEMORY); 206 } 207 208 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 209 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 210 211 if (MemRover) 212 { 213 /* Return the physical address */ 214 215 PhysicalAddress = (UINT32) 216 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); 217 218 *TableAddress = PhysicalAddress; 219 return_ACPI_STATUS (AE_OK); 220 } 221 222 /* A valid RSDP was not found */ 223 224 ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found")); 225 return_ACPI_STATUS (AE_NOT_FOUND); 226 } 227 228 ACPI_EXPORT_SYMBOL (AcpiFindRootPointer) 229 230 231 /******************************************************************************* 232 * 233 * FUNCTION: AcpiTbScanMemoryForRsdp 234 * 235 * PARAMETERS: StartAddress - Starting pointer for search 236 * Length - Maximum length to search 237 * 238 * RETURN: Pointer to the RSDP if found, otherwise NULL. 239 * 240 * DESCRIPTION: Search a block of memory for the RSDP signature 241 * 242 ******************************************************************************/ 243 244 UINT8 * 245 AcpiTbScanMemoryForRsdp ( 246 UINT8 *StartAddress, 247 UINT32 Length) 248 { 249 ACPI_STATUS Status; 250 UINT8 *MemRover; 251 UINT8 *EndAddress; 252 253 254 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); 255 256 257 EndAddress = StartAddress + Length; 258 259 /* Search from given start address for the requested length */ 260 261 for (MemRover = StartAddress; MemRover < EndAddress; 262 MemRover += ACPI_RSDP_SCAN_STEP) 263 { 264 /* The RSDP signature and checksum must both be correct */ 265 266 Status = AcpiTbValidateRsdp (ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); 267 if (ACPI_SUCCESS (Status)) 268 { 269 /* Sig and checksum valid, we have found a real RSDP */ 270 271 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 272 "RSDP located at physical address %p\n", MemRover)); 273 return_PTR (MemRover); 274 } 275 276 /* No sig match or bad checksum, keep searching */ 277 } 278 279 /* Searched entire block, no RSDP was found */ 280 281 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 282 "Searched entire block from %p, valid RSDP was not found\n", 283 StartAddress)); 284 return_PTR (NULL); 285 } 286