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 - 2015, 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 #include "acpi.h" 117 #include "accommon.h" 118 #include "actables.h" 119 120 121 #define _COMPONENT ACPI_TABLES 122 ACPI_MODULE_NAME ("tbxfroot") 123 124 125 /******************************************************************************* 126 * 127 * FUNCTION: AcpiTbGetRsdpLength 128 * 129 * PARAMETERS: Rsdp - Pointer to RSDP 130 * 131 * RETURN: Table length 132 * 133 * DESCRIPTION: Get the length of the RSDP 134 * 135 ******************************************************************************/ 136 137 UINT32 138 AcpiTbGetRsdpLength ( 139 ACPI_TABLE_RSDP *Rsdp) 140 { 141 142 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 143 { 144 /* BAD Signature */ 145 146 return (0); 147 } 148 149 /* "Length" field is available if table version >= 2 */ 150 151 if (Rsdp->Revision >= 2) 152 { 153 return (Rsdp->Length); 154 } 155 else 156 { 157 return (ACPI_RSDP_CHECKSUM_LENGTH); 158 } 159 } 160 161 162 /******************************************************************************* 163 * 164 * FUNCTION: AcpiTbValidateRsdp 165 * 166 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP 167 * 168 * RETURN: Status 169 * 170 * DESCRIPTION: Validate the RSDP (ptr) 171 * 172 ******************************************************************************/ 173 174 ACPI_STATUS 175 AcpiTbValidateRsdp ( 176 ACPI_TABLE_RSDP *Rsdp) 177 { 178 179 /* 180 * The signature and checksum must both be correct 181 * 182 * Note: Sometimes there exists more than one RSDP in memory; the valid 183 * RSDP has a valid checksum, all others have an invalid checksum. 184 */ 185 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 186 { 187 /* Nope, BAD Signature */ 188 189 return (AE_BAD_SIGNATURE); 190 } 191 192 /* Check the standard checksum */ 193 194 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) 195 { 196 return (AE_BAD_CHECKSUM); 197 } 198 199 /* Check extended checksum if table version >= 2 */ 200 201 if ((Rsdp->Revision >= 2) && 202 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) 203 { 204 return (AE_BAD_CHECKSUM); 205 } 206 207 return (AE_OK); 208 } 209 210 211 /******************************************************************************* 212 * 213 * FUNCTION: AcpiFindRootPointer 214 * 215 * PARAMETERS: TableAddress - Where the table pointer is returned 216 * 217 * RETURN: Status, RSDP physical address 218 * 219 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor 220 * pointer structure. If it is found, set *RSDP to point to it. 221 * 222 * NOTE1: The RSDP must be either in the first 1K of the Extended 223 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) 224 * Only a 32-bit physical address is necessary. 225 * 226 * NOTE2: This function is always available, regardless of the 227 * initialization state of the rest of ACPI. 228 * 229 ******************************************************************************/ 230 231 ACPI_STATUS 232 AcpiFindRootPointer ( 233 ACPI_PHYSICAL_ADDRESS *TableAddress) 234 { 235 UINT8 *TablePtr; 236 UINT8 *MemRover; 237 UINT32 PhysicalAddress; 238 239 240 ACPI_FUNCTION_TRACE (AcpiFindRootPointer); 241 242 243 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ 244 245 TablePtr = AcpiOsMapMemory ( 246 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, 247 ACPI_EBDA_PTR_LENGTH); 248 if (!TablePtr) 249 { 250 ACPI_ERROR ((AE_INFO, 251 "Could not map memory at 0x%8.8X for length %u", 252 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); 253 254 return_ACPI_STATUS (AE_NO_MEMORY); 255 } 256 257 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); 258 259 /* Convert segment part to physical address */ 260 261 PhysicalAddress <<= 4; 262 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); 263 264 /* EBDA present? */ 265 266 if (PhysicalAddress > 0x400) 267 { 268 /* 269 * 1b) Search EBDA paragraphs (EBDA is required to be a 270 * minimum of 1K length) 271 */ 272 TablePtr = AcpiOsMapMemory ( 273 (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, 274 ACPI_EBDA_WINDOW_SIZE); 275 if (!TablePtr) 276 { 277 ACPI_ERROR ((AE_INFO, 278 "Could not map memory at 0x%8.8X for length %u", 279 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); 280 281 return_ACPI_STATUS (AE_NO_MEMORY); 282 } 283 284 MemRover = AcpiTbScanMemoryForRsdp ( 285 TablePtr, ACPI_EBDA_WINDOW_SIZE); 286 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); 287 288 if (MemRover) 289 { 290 /* Return the physical address */ 291 292 PhysicalAddress += 293 (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); 294 295 *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress; 296 return_ACPI_STATUS (AE_OK); 297 } 298 } 299 300 /* 301 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh 302 */ 303 TablePtr = AcpiOsMapMemory ( 304 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, 305 ACPI_HI_RSDP_WINDOW_SIZE); 306 307 if (!TablePtr) 308 { 309 ACPI_ERROR ((AE_INFO, 310 "Could not map memory at 0x%8.8X for length %u", 311 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); 312 313 return_ACPI_STATUS (AE_NO_MEMORY); 314 } 315 316 MemRover = AcpiTbScanMemoryForRsdp ( 317 TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 318 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 319 320 if (MemRover) 321 { 322 /* Return the physical address */ 323 324 PhysicalAddress = (UINT32) 325 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); 326 327 *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress; 328 return_ACPI_STATUS (AE_OK); 329 } 330 331 /* A valid RSDP was not found */ 332 333 ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found")); 334 return_ACPI_STATUS (AE_NOT_FOUND); 335 } 336 337 ACPI_EXPORT_SYMBOL (AcpiFindRootPointer) 338 339 340 /******************************************************************************* 341 * 342 * FUNCTION: AcpiTbScanMemoryForRsdp 343 * 344 * PARAMETERS: StartAddress - Starting pointer for search 345 * Length - Maximum length to search 346 * 347 * RETURN: Pointer to the RSDP if found, otherwise NULL. 348 * 349 * DESCRIPTION: Search a block of memory for the RSDP signature 350 * 351 ******************************************************************************/ 352 353 UINT8 * 354 AcpiTbScanMemoryForRsdp ( 355 UINT8 *StartAddress, 356 UINT32 Length) 357 { 358 ACPI_STATUS Status; 359 UINT8 *MemRover; 360 UINT8 *EndAddress; 361 362 363 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); 364 365 366 EndAddress = StartAddress + Length; 367 368 /* Search from given start address for the requested length */ 369 370 for (MemRover = StartAddress; MemRover < EndAddress; 371 MemRover += ACPI_RSDP_SCAN_STEP) 372 { 373 /* The RSDP signature and checksum must both be correct */ 374 375 Status = AcpiTbValidateRsdp ( 376 ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); 377 if (ACPI_SUCCESS (Status)) 378 { 379 /* Sig and checksum valid, we have found a real RSDP */ 380 381 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 382 "RSDP located at physical address %p\n", MemRover)); 383 return_PTR (MemRover); 384 } 385 386 /* No sig match or bad checksum, keep searching */ 387 } 388 389 /* Searched entire block, no RSDP was found */ 390 391 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 392 "Searched entire block from %p, valid RSDP was not found\n", 393 StartAddress)); 394 return_PTR (NULL); 395 } 396