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 47 static ACPI_TABLE_RSDP *biosacpi_find_rsdp(void); 48 static ACPI_TABLE_RSDP *biosacpi_search_rsdp(char *base, int length); 49 50 #define RSDP_CHECKSUM_LENGTH 20 51 52 void 53 biosacpi_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 /* 64 * Report the RSDP to the kernel. While this can be found with 65 * a BIOS boot, the RSDP may be elsewhere when booted from UEFI. 66 * The old code used the 'hints' method to communite this to 67 * the kernel. However, while convenient, the 'hints' method 68 * is fragile and does not work when static hints are compiled 69 * into the kernel. Instead, move to setting different tunables 70 * that start with acpi. The old 'hints' can be removed before 71 * we branch for FreeBSD 12. 72 */ 73 sprintf(buf, "0x%08x", VTOP(rsdp)); 74 setenv("hint.acpi.0.rsdp", buf, 1); 75 setenv("acpi.rsdp", buf, 1); 76 revision = rsdp->Revision; 77 if (revision == 0) 78 revision = 1; 79 sprintf(buf, "%d", revision); 80 setenv("hint.acpi.0.revision", buf, 1); 81 setenv("acpi.revision", buf, 1); 82 strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId)); 83 buf[sizeof(rsdp->OemId)] = '\0'; 84 setenv("hint.acpi.0.oem", buf, 1); 85 setenv("acpi.oem", buf, 1); 86 sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress); 87 setenv("hint.acpi.0.rsdt", buf, 1); 88 setenv("acpi.rsdt", buf, 1); 89 if (revision >= 2) { 90 /* XXX extended checksum? */ 91 sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress); 92 setenv("hint.acpi.0.xsdt", buf, 1); 93 setenv("acpi.xsdt", buf, 1); 94 sprintf(buf, "%d", rsdp->Length); 95 setenv("hint.acpi.0.xsdt_length", buf, 1); 96 setenv("acpi.xsdt_length", buf, 1); 97 } 98 } 99 100 /* 101 * Find the RSDP in low memory. See section 5.2.2 of the ACPI spec. 102 */ 103 static ACPI_TABLE_RSDP * 104 biosacpi_find_rsdp(void) 105 { 106 ACPI_TABLE_RSDP *rsdp; 107 uint16_t *addr; 108 109 /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */ 110 addr = (uint16_t *)PTOV(0x40E); 111 if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != NULL) 112 return (rsdp); 113 114 /* Check the upper memory BIOS space, 0xe0000 - 0xfffff. */ 115 if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL) 116 return (rsdp); 117 118 return (NULL); 119 } 120 121 static ACPI_TABLE_RSDP * 122 biosacpi_search_rsdp(char *base, int length) 123 { 124 ACPI_TABLE_RSDP *rsdp; 125 uint8_t *cp, sum; 126 int ofs, idx; 127 128 /* search on 16-byte boundaries */ 129 for (ofs = 0; ofs < length; ofs += 16) { 130 rsdp = (ACPI_TABLE_RSDP *)PTOV(base + ofs); 131 132 /* compare signature, validate checksum */ 133 if (!strncmp(rsdp->Signature, ACPI_SIG_RSDP, strlen(ACPI_SIG_RSDP))) { 134 cp = (uint8_t *)rsdp; 135 sum = 0; 136 for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++) 137 sum += *(cp + idx); 138 if (sum != 0) 139 continue; 140 return(rsdp); 141 } 142 } 143 return(NULL); 144 } 145