1/*- 2 * Copyright (c) 2001 Michael Smith <msmith@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <stand.h> 31#include <machine/stdarg.h> 32#include <bootstrap.h> 33#include <btxv86.h> 34#include "libi386.h" 35 36#include "platform/acfreebsd.h" 37#include "acconfig.h" 38#define ACPI_SYSTEM_XFACE 39#include "actypes.h" 40#include "actbl.h" 41 42/* 43 * Detect ACPI and export information about the ACPI BIOS into the 44 * environment. 45 */ 46 47static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void); 48static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length); 49 50#define RSDP_CHECKSUM_LENGTH 20 51 52void 53biosacpi_detect(void) 54{ 55 ACPI_TABLE_RSDP *rsdp; 56 char buf[24]; 57 int revision; 58 59 /* locate and validate the RSDP */ 60 if ((rsdp = biosacpi_find_rsdp()) == NULL) 61 return; 62 63 /* export values from the RSDP */ 64 sprintf(buf, "%u", VTOP(rsdp)); 65 setenv("hint.acpi.0.rsdp", buf, 1); 66 revision = rsdp->Revision; 67 if (revision == 0) 68 revision = 1; 69 sprintf(buf, "%d", revision); 70 setenv("hint.acpi.0.revision", buf, 1); 71 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId)); 72 buf[sizeof(rsdp->OemId)] = '\0'; 73 setenv("hint.acpi.0.oem", buf, 1); 74 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress); 75 setenv("hint.acpi.0.rsdt", buf, 1); 76 if (revision >= 2) { 77 /* XXX extended checksum? */ 78 sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress); 79 setenv("hint.acpi.0.xsdt", buf, 1); 80 sprintf(buf, "%d", rsdp->Length); 81 setenv("hint.acpi.0.xsdt_length", buf, 1); 82 } 83} 84 85/* 86 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec. 87 */ 88static ACPI_TABLE_RSDP * 89biosacpi_find_rsdp(void) 90{ 91 ACPI_TABLE_RSDP *rsdp; 92 uint16_t *addr; 93 94 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */ 95 addr = (uint16_t *)PTOV(0x40E); 96 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL) 97 return (rsdp); 98 99 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */ 100 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL) 101 return (rsdp); 102 103 return (NULL); 104} 105 106static ACPI_TABLE_RSDP * 107biosacpi_search_rsdp(char *base, int length) 108{ 109 ACPI_TABLE_RSDP *rsdp; 110 u_int8_t *cp, sum; 111 int ofs, idx; 112 113 /* search on 16-byte boundaries */ 114 for (ofs = 0; ofs < length; ofs += 16) { 115 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs); 116 117 /* compare signature, validate checksum */ 118 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) { 119 cp = (u_int8_t *)rsdp; 120 sum = 0; 121 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++) 122 sum += *(cp + idx); 123 if (sum != 0) 124 continue; 125 return(rsdp); 126 } 127 } 128 return(NULL); 129} 130