1 /****************************************************************************** 2 * 3 * Module Name: tbxfroot - Find the root ACPI table (RSDT) 4 * 5 *****************************************************************************/ 6 7 /****************************************************************************** 8 * 9 * 1. Copyright Notice 10 * 11 * Some or all of this work - Copyright (c) 1999 - 2013, Intel Corp. 12 * All rights reserved. 13 * 14 * 2. License 15 * 16 * 2.1. This is your license from Intel Corp. under its intellectual property 17 * rights. You may have additional license terms from the party that provided 18 * you this software, covering your right to use that party's intellectual 19 * property rights. 20 * 21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 22 * copy of the source code appearing in this file ("Covered Code") an 23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 24 * base code distributed originally by Intel ("Original Intel Code") to copy, 25 * make derivatives, distribute, use and display any portion of the Covered 26 * Code in any form, with the right to sublicense such rights; and 27 * 28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 29 * license (with the right to sublicense), under only those claims of Intel 30 * patents that are infringed by the Original Intel Code, to make, use, sell, 31 * offer to sell, and import the Covered Code and derivative works thereof 32 * solely to the minimum extent necessary to exercise the above copyright 33 * license, and in no event shall the patent license extend to any additions 34 * to or modifications of the Original Intel Code. No other license or right 35 * is granted directly or by implication, estoppel or otherwise; 36 * 37 * The above copyright and patent license is granted only if the following 38 * conditions are met: 39 * 40 * 3. Conditions 41 * 42 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 43 * Redistribution of source code of any substantial portion of the Covered 44 * Code or modification with rights to further distribute source must include 45 * the above Copyright Notice, the above License, this list of Conditions, 46 * and the following Disclaimer and Export Compliance provision. In addition, 47 * Licensee must cause all Covered Code to which Licensee contributes to 48 * contain a file documenting the changes Licensee made to create that Covered 49 * Code and the date of any change. Licensee must include in that file the 50 * documentation of any changes made by any predecessor Licensee. Licensee 51 * must include a prominent statement that the modification is derived, 52 * directly or indirectly, from Original Intel Code. 53 * 54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 55 * Redistribution of source code of any substantial portion of the Covered 56 * Code or modification without rights to further distribute source must 57 * include the following Disclaimer and Export Compliance provision in the 58 * documentation and/or other materials provided with distribution. In 59 * addition, Licensee may not authorize further sublicense of source of any 60 * portion of the Covered Code, and must include terms to the effect that the 61 * license from Licensee to its licensee is limited to the intellectual 62 * property embodied in the software Licensee provides to its licensee, and 63 * not to intellectual property embodied in modifications its licensee may 64 * make. 65 * 66 * 3.3. Redistribution of Executable. Redistribution in executable form of any 67 * substantial portion of the Covered Code or modification must reproduce the 68 * above Copyright Notice, and the following Disclaimer and Export Compliance 69 * provision in the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3.4. Intel retains all right, title, and interest in and to the Original 73 * Intel Code. 74 * 75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 76 * Intel shall be used in advertising or otherwise to promote the sale, use or 77 * other dealings in products derived from or relating to the Covered Code 78 * without prior written authorization from Intel. 79 * 80 * 4. Disclaimer and Export Compliance 81 * 82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 88 * PARTICULAR PURPOSE. 89 * 90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 97 * LIMITED REMEDY. 98 * 99 * 4.3. Licensee shall not export, either directly or indirectly, any of this 100 * software or system incorporating such software without first obtaining any 101 * required license or other approval from the U. S. Department of Commerce or 102 * any other agency or department of the United States Government. In the 103 * event Licensee exports any such software from the United States or 104 * re-exports any such software from a foreign destination, Licensee shall 105 * ensure that the distribution and export/re-export of the software is in 106 * compliance with all laws, regulations, orders, or other restrictions of the 107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 108 * any of its subsidiaries will export/re-export any technical data, process, 109 * software, or service, directly or indirectly, to any country for which the 110 * United States government or any agency thereof requires an export license, 111 * other governmental approval, or letter of assurance, without first obtaining 112 * such license, approval or letter. 113 * 114 *****************************************************************************/ 115 116 #define __TBXFROOT_C__ 117 118 #include "acpi.h" 119 #include "accommon.h" 120 #include "actables.h" 121 122 123 #define _COMPONENT ACPI_TABLES 124 ACPI_MODULE_NAME ("tbxfroot") 125 126 127 /******************************************************************************* 128 * 129 * FUNCTION: AcpiTbValidateRsdp 130 * 131 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP 132 * 133 * RETURN: Status 134 * 135 * DESCRIPTION: Validate the RSDP (ptr) 136 * 137 ******************************************************************************/ 138 139 ACPI_STATUS 140 AcpiTbValidateRsdp ( 141 ACPI_TABLE_RSDP *Rsdp) 142 { 143 144 /* 145 * The signature and checksum must both be correct 146 * 147 * Note: Sometimes there exists more than one RSDP in memory; the valid 148 * RSDP has a valid checksum, all others have an invalid checksum. 149 */ 150 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 151 { 152 /* Nope, BAD Signature */ 153 154 return (AE_BAD_SIGNATURE); 155 } 156 157 /* Check the standard checksum */ 158 159 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) 160 { 161 return (AE_BAD_CHECKSUM); 162 } 163 164 /* Check extended checksum if table version >= 2 */ 165 166 if ((Rsdp->Revision >= 2) && 167 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) 168 { 169 return (AE_BAD_CHECKSUM); 170 } 171 172 return (AE_OK); 173 } 174 175 176 /******************************************************************************* 177 * 178 * FUNCTION: AcpiFindRootPointer 179 * 180 * PARAMETERS: TableAddress - Where the table pointer is returned 181 * 182 * RETURN: Status, RSDP physical address 183 * 184 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor 185 * pointer structure. If it is found, set *RSDP to point to it. 186 * 187 * NOTE1: The RSDP must be either in the first 1K of the Extended 188 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) 189 * Only a 32-bit physical address is necessary. 190 * 191 * NOTE2: This function is always available, regardless of the 192 * initialization state of the rest of ACPI. 193 * 194 ******************************************************************************/ 195 196 ACPI_STATUS 197 AcpiFindRootPointer ( 198 ACPI_SIZE *TableAddress) 199 { 200 UINT8 *TablePtr; 201 UINT8 *MemRover; 202 UINT32 PhysicalAddress; 203 204 205 ACPI_FUNCTION_TRACE (AcpiFindRootPointer); 206 207 208 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ 209 210 TablePtr = AcpiOsMapMemory ( 211 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, 212 ACPI_EBDA_PTR_LENGTH); 213 if (!TablePtr) 214 { 215 ACPI_ERROR ((AE_INFO, 216 "Could not map memory at 0x%8.8X for length %u", 217 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); 218 219 return_ACPI_STATUS (AE_NO_MEMORY); 220 } 221 222 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); 223 224 /* Convert segment part to physical address */ 225 226 PhysicalAddress <<= 4; 227 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); 228 229 /* EBDA present? */ 230 231 if (PhysicalAddress > 0x400) 232 { 233 /* 234 * 1b) Search EBDA paragraphs (EBDA is required to be a 235 * minimum of 1K length) 236 */ 237 TablePtr = AcpiOsMapMemory ( 238 (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, 239 ACPI_EBDA_WINDOW_SIZE); 240 if (!TablePtr) 241 { 242 ACPI_ERROR ((AE_INFO, 243 "Could not map memory at 0x%8.8X for length %u", 244 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); 245 246 return_ACPI_STATUS (AE_NO_MEMORY); 247 } 248 249 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_EBDA_WINDOW_SIZE); 250 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); 251 252 if (MemRover) 253 { 254 /* Return the physical address */ 255 256 PhysicalAddress += (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); 257 258 *TableAddress = PhysicalAddress; 259 return_ACPI_STATUS (AE_OK); 260 } 261 } 262 263 /* 264 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh 265 */ 266 TablePtr = AcpiOsMapMemory ( 267 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, 268 ACPI_HI_RSDP_WINDOW_SIZE); 269 270 if (!TablePtr) 271 { 272 ACPI_ERROR ((AE_INFO, 273 "Could not map memory at 0x%8.8X for length %u", 274 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); 275 276 return_ACPI_STATUS (AE_NO_MEMORY); 277 } 278 279 MemRover = AcpiTbScanMemoryForRsdp (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 280 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 281 282 if (MemRover) 283 { 284 /* Return the physical address */ 285 286 PhysicalAddress = (UINT32) 287 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); 288 289 *TableAddress = PhysicalAddress; 290 return_ACPI_STATUS (AE_OK); 291 } 292 293 /* A valid RSDP was not found */ 294 295 ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found")); 296 return_ACPI_STATUS (AE_NOT_FOUND); 297 } 298 299 ACPI_EXPORT_SYMBOL (AcpiFindRootPointer) 300 301 302 /******************************************************************************* 303 * 304 * FUNCTION: AcpiTbScanMemoryForRsdp 305 * 306 * PARAMETERS: StartAddress - Starting pointer for search 307 * Length - Maximum length to search 308 * 309 * RETURN: Pointer to the RSDP if found, otherwise NULL. 310 * 311 * DESCRIPTION: Search a block of memory for the RSDP signature 312 * 313 ******************************************************************************/ 314 315 UINT8 * 316 AcpiTbScanMemoryForRsdp ( 317 UINT8 *StartAddress, 318 UINT32 Length) 319 { 320 ACPI_STATUS Status; 321 UINT8 *MemRover; 322 UINT8 *EndAddress; 323 324 325 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); 326 327 328 EndAddress = StartAddress + Length; 329 330 /* Search from given start address for the requested length */ 331 332 for (MemRover = StartAddress; MemRover < EndAddress; 333 MemRover += ACPI_RSDP_SCAN_STEP) 334 { 335 /* The RSDP signature and checksum must both be correct */ 336 337 Status = AcpiTbValidateRsdp (ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); 338 if (ACPI_SUCCESS (Status)) 339 { 340 /* Sig and checksum valid, we have found a real RSDP */ 341 342 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 343 "RSDP located at physical address %p\n", MemRover)); 344 return_PTR (MemRover); 345 } 346 347 /* No sig match or bad checksum, keep searching */ 348 } 349 350 /* Searched entire block, no RSDP was found */ 351 352 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 353 "Searched entire block from %p, valid RSDP was not found\n", 354 StartAddress)); 355 return_PTR (NULL); 356 } 357