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 29 #include <stand.h> 30 #include <machine/stdarg.h> 31 #include <bootstrap.h> 32 #include <btxv86.h> 33 #include "libi386.h" 34 35 #include "platform/acfreebsd.h" 36 #include "acconfig.h" 37 #define ACPI_SYSTEM_XFACE 38 #include "actypes.h" 39 #include "actbl.h" 40 41 /* 42 * Detect ACPI and export information about the ACPI BIOS into the 43 * environment. 44 */ 45 46 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void); 47 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length); 48 49 #define RSDP_CHECKSUM_LENGTH 20 50 51 void 52 biosacpi_detect(void) 53 { 54 ACPI_TABLE_RSDP *rsdp; 55 char buf[24]; 56 int revision; 57 58 /* locate and validate the RSDP */ 59 if ((rsdp = biosacpi_find_rsdp()) == NULL) 60 return; 61 62 /* export values from the RSDP */ 63 sprintf(buf, "0x%08x", (unsigned int)VTOP(rsdp)); 64 setenv("acpi.rsdp", buf, 1); 65 revision = rsdp->Revision; 66 if (revision == 0) 67 revision = 1; 68 sprintf(buf, "%d", revision); 69 setenv("acpi.revision", buf, 1); 70 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId)); 71 buf[sizeof(rsdp->OemId)] = '\0'; 72 setenv("acpi.oem", buf, 1); 73 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress); 74 setenv("acpi.rsdt", buf, 1); 75 if (revision >= 2) { 76 /* XXX extended checksum? */ 77 sprintf(buf, "0x%016llx", 78 (unsigned long long)rsdp->XsdtPhysicalAddress); 79 setenv("acpi.xsdt", buf, 1); 80 sprintf(buf, "%d", rsdp->Length); 81 setenv("acpi.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 */ 88 static ACPI_TABLE_RSDP * 89 biosacpi_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 rsdp = biosacpi_search_rsdp((char *)(intptr_t)(*addr << 4), 0x400); 97 if (rsdp != NULL) 98 return (rsdp); 99 100 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */ 101 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL) 102 return (rsdp); 103 104 return (NULL); 105 } 106 107 static ACPI_TABLE_RSDP * 108 biosacpi_search_rsdp(char *base, int length) 109 { 110 ACPI_TABLE_RSDP *rsdp; 111 u_int8_t *cp, sum; 112 int ofs, idx; 113 114 /* search on 16-byte boundaries */ 115 for (ofs = 0; ofs < length; ofs += 16) { 116 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs); 117 118 /* compare signature, validate checksum */ 119 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) { 120 cp = (u_int8_t *)rsdp; 121 sum = 0; 122 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++) 123 sum += *(cp + idx); 124 if (sum != 0) 125 continue; 126 return(rsdp); 127 } 128 } 129 return(NULL); 130 } 131