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 - 2018, 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 * Alternatively, you may choose to be licensed under the terms of the 117 * following license: 118 * 119 * Redistribution and use in source and binary forms, with or without 120 * modification, are permitted provided that the following conditions 121 * are met: 122 * 1. Redistributions of source code must retain the above copyright 123 * notice, this list of conditions, and the following disclaimer, 124 * without modification. 125 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 126 * substantially similar to the "NO WARRANTY" disclaimer below 127 * ("Disclaimer") and any redistribution must be conditioned upon 128 * including a substantially similar Disclaimer requirement for further 129 * binary redistribution. 130 * 3. Neither the names of the above-listed copyright holders nor the names 131 * of any contributors may be used to endorse or promote products derived 132 * from this software without specific prior written permission. 133 * 134 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 135 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 136 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 137 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 138 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 139 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 140 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 141 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 142 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 143 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 144 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 145 * 146 * Alternatively, you may choose to be licensed under the terms of the 147 * GNU General Public License ("GPL") version 2 as published by the Free 148 * Software Foundation. 149 * 150 *****************************************************************************/ 151 152 #include "acpi.h" 153 #include "accommon.h" 154 #include "actables.h" 155 156 157 #define _COMPONENT ACPI_TABLES 158 ACPI_MODULE_NAME ("tbxfroot") 159 160 161 /******************************************************************************* 162 * 163 * FUNCTION: AcpiTbGetRsdpLength 164 * 165 * PARAMETERS: Rsdp - Pointer to RSDP 166 * 167 * RETURN: Table length 168 * 169 * DESCRIPTION: Get the length of the RSDP 170 * 171 ******************************************************************************/ 172 173 UINT32 174 AcpiTbGetRsdpLength ( 175 ACPI_TABLE_RSDP *Rsdp) 176 { 177 178 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 179 { 180 /* BAD Signature */ 181 182 return (0); 183 } 184 185 /* "Length" field is available if table version >= 2 */ 186 187 if (Rsdp->Revision >= 2) 188 { 189 return (Rsdp->Length); 190 } 191 else 192 { 193 return (ACPI_RSDP_CHECKSUM_LENGTH); 194 } 195 } 196 197 198 /******************************************************************************* 199 * 200 * FUNCTION: AcpiTbValidateRsdp 201 * 202 * PARAMETERS: Rsdp - Pointer to unvalidated RSDP 203 * 204 * RETURN: Status 205 * 206 * DESCRIPTION: Validate the RSDP (ptr) 207 * 208 ******************************************************************************/ 209 210 ACPI_STATUS 211 AcpiTbValidateRsdp ( 212 ACPI_TABLE_RSDP *Rsdp) 213 { 214 215 /* 216 * The signature and checksum must both be correct 217 * 218 * Note: Sometimes there exists more than one RSDP in memory; the valid 219 * RSDP has a valid checksum, all others have an invalid checksum. 220 */ 221 if (!ACPI_VALIDATE_RSDP_SIG (Rsdp->Signature)) 222 { 223 /* Nope, BAD Signature */ 224 225 return (AE_BAD_SIGNATURE); 226 } 227 228 /* Check the standard checksum */ 229 230 if (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) 231 { 232 return (AE_BAD_CHECKSUM); 233 } 234 235 /* Check extended checksum if table version >= 2 */ 236 237 if ((Rsdp->Revision >= 2) && 238 (AcpiTbChecksum ((UINT8 *) Rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) 239 { 240 return (AE_BAD_CHECKSUM); 241 } 242 243 return (AE_OK); 244 } 245 246 247 /******************************************************************************* 248 * 249 * FUNCTION: AcpiFindRootPointer 250 * 251 * PARAMETERS: TableAddress - Where the table pointer is returned 252 * 253 * RETURN: Status, RSDP physical address 254 * 255 * DESCRIPTION: Search lower 1Mbyte of memory for the root system descriptor 256 * pointer structure. If it is found, set *RSDP to point to it. 257 * 258 * NOTE1: The RSDP must be either in the first 1K of the Extended 259 * BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.) 260 * Only a 32-bit physical address is necessary. 261 * 262 * NOTE2: This function is always available, regardless of the 263 * initialization state of the rest of ACPI. 264 * 265 ******************************************************************************/ 266 267 ACPI_STATUS ACPI_INIT_FUNCTION 268 AcpiFindRootPointer ( 269 ACPI_PHYSICAL_ADDRESS *TableAddress) 270 { 271 UINT8 *TablePtr; 272 UINT8 *MemRover; 273 UINT32 PhysicalAddress; 274 275 276 ACPI_FUNCTION_TRACE (AcpiFindRootPointer); 277 278 279 /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */ 280 281 TablePtr = AcpiOsMapMemory ( 282 (ACPI_PHYSICAL_ADDRESS) ACPI_EBDA_PTR_LOCATION, 283 ACPI_EBDA_PTR_LENGTH); 284 if (!TablePtr) 285 { 286 ACPI_ERROR ((AE_INFO, 287 "Could not map memory at 0x%8.8X for length %u", 288 ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH)); 289 290 return_ACPI_STATUS (AE_NO_MEMORY); 291 } 292 293 ACPI_MOVE_16_TO_32 (&PhysicalAddress, TablePtr); 294 295 /* Convert segment part to physical address */ 296 297 PhysicalAddress <<= 4; 298 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_PTR_LENGTH); 299 300 /* EBDA present? */ 301 302 if (PhysicalAddress > 0x400) 303 { 304 /* 305 * 1b) Search EBDA paragraphs (EBDA is required to be a 306 * minimum of 1K length) 307 */ 308 TablePtr = AcpiOsMapMemory ( 309 (ACPI_PHYSICAL_ADDRESS) PhysicalAddress, 310 ACPI_EBDA_WINDOW_SIZE); 311 if (!TablePtr) 312 { 313 ACPI_ERROR ((AE_INFO, 314 "Could not map memory at 0x%8.8X for length %u", 315 PhysicalAddress, ACPI_EBDA_WINDOW_SIZE)); 316 317 return_ACPI_STATUS (AE_NO_MEMORY); 318 } 319 320 MemRover = AcpiTbScanMemoryForRsdp ( 321 TablePtr, ACPI_EBDA_WINDOW_SIZE); 322 AcpiOsUnmapMemory (TablePtr, ACPI_EBDA_WINDOW_SIZE); 323 324 if (MemRover) 325 { 326 /* Return the physical address */ 327 328 PhysicalAddress += 329 (UINT32) ACPI_PTR_DIFF (MemRover, TablePtr); 330 331 *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress; 332 return_ACPI_STATUS (AE_OK); 333 } 334 } 335 336 /* 337 * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh 338 */ 339 TablePtr = AcpiOsMapMemory ( 340 (ACPI_PHYSICAL_ADDRESS) ACPI_HI_RSDP_WINDOW_BASE, 341 ACPI_HI_RSDP_WINDOW_SIZE); 342 343 if (!TablePtr) 344 { 345 ACPI_ERROR ((AE_INFO, 346 "Could not map memory at 0x%8.8X for length %u", 347 ACPI_HI_RSDP_WINDOW_BASE, ACPI_HI_RSDP_WINDOW_SIZE)); 348 349 return_ACPI_STATUS (AE_NO_MEMORY); 350 } 351 352 MemRover = AcpiTbScanMemoryForRsdp ( 353 TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 354 AcpiOsUnmapMemory (TablePtr, ACPI_HI_RSDP_WINDOW_SIZE); 355 356 if (MemRover) 357 { 358 /* Return the physical address */ 359 360 PhysicalAddress = (UINT32) 361 (ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (MemRover, TablePtr)); 362 363 *TableAddress = (ACPI_PHYSICAL_ADDRESS) PhysicalAddress; 364 return_ACPI_STATUS (AE_OK); 365 } 366 367 /* A valid RSDP was not found */ 368 369 ACPI_BIOS_ERROR ((AE_INFO, "A valid RSDP was not found")); 370 return_ACPI_STATUS (AE_NOT_FOUND); 371 } 372 373 ACPI_EXPORT_SYMBOL_INIT (AcpiFindRootPointer) 374 375 376 /******************************************************************************* 377 * 378 * FUNCTION: AcpiTbScanMemoryForRsdp 379 * 380 * PARAMETERS: StartAddress - Starting pointer for search 381 * Length - Maximum length to search 382 * 383 * RETURN: Pointer to the RSDP if found, otherwise NULL. 384 * 385 * DESCRIPTION: Search a block of memory for the RSDP signature 386 * 387 ******************************************************************************/ 388 389 UINT8 * 390 AcpiTbScanMemoryForRsdp ( 391 UINT8 *StartAddress, 392 UINT32 Length) 393 { 394 ACPI_STATUS Status; 395 UINT8 *MemRover; 396 UINT8 *EndAddress; 397 398 399 ACPI_FUNCTION_TRACE (TbScanMemoryForRsdp); 400 401 402 EndAddress = StartAddress + Length; 403 404 /* Search from given start address for the requested length */ 405 406 for (MemRover = StartAddress; MemRover < EndAddress; 407 MemRover += ACPI_RSDP_SCAN_STEP) 408 { 409 /* The RSDP signature and checksum must both be correct */ 410 411 Status = AcpiTbValidateRsdp ( 412 ACPI_CAST_PTR (ACPI_TABLE_RSDP, MemRover)); 413 if (ACPI_SUCCESS (Status)) 414 { 415 /* Sig and checksum valid, we have found a real RSDP */ 416 417 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 418 "RSDP located at physical address %p\n", MemRover)); 419 return_PTR (MemRover); 420 } 421 422 /* No sig match or bad checksum, keep searching */ 423 } 424 425 /* Searched entire block, no RSDP was found */ 426 427 ACPI_DEBUG_PRINT ((ACPI_DB_INFO, 428 "Searched entire block from %p, valid RSDP was not found\n", 429 StartAddress)); 430 return_PTR (NULL); 431 } 432