sys/boot/pc32/libi386/biosacpi.c

   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  * $FreeBSD: src/sys/boot/i386/libi386/biosacpi.c,v 1.7 2003/08/25 23:28:31 obrien Exp $
  27  * $DragonFly: src/sys/boot/pc32/libi386/biosacpi.c,v 1.4 2005/08/16 10:31:35 y0netan1 Exp $
  28  */
  29
  30 #include <stand.h>
  31 #include <machine/stdarg.h>
  32 #include <bootstrap.h>
  33
  34 #include "acdragonfly.h"
  35 #include "acconfig.h"
  36 #define ACPI_SYSTEM_XFACE
  37 #include "actypes.h"
  38 #include "actbl.h"
  39
  40 /*
  41  * Detect ACPI and export information about the APCI BIOS into the
  42  * environment.
  43  */
  44
  45 static RSDP_DESCRIPTOR  *biosacpi_find_rsdp(void);
  46 static RSDP_DESCRIPTOR  *biosacpi_search_rsdp(char *base, int length);
  47
  48 #define RSDP_CHECKSUM_LENGTH 20
  49
  50 void
  51 biosacpi_detect(void)
  52 {
  53     RSDP_DESCRIPTOR     *rsdp;
  54     char                buf[160];
  55     int                 revision;
  56
  57     /* XXX check the BIOS datestamp */
  58
  59     /* locate and validate the RSDP */
  60     if ((rsdp = biosacpi_find_rsdp()) == NULL)
  61         return;
  62
  63     /* export values from the RSDP */
  64     revision = rsdp->Revision;
  65     if (revision == 0)
  66         revision = 1;
  67     sprintf(buf, "%d", revision);
  68     setenv("hint.acpi.0.revision", buf, 1);
  69     strncpy(buf, rsdp->OemId, sizeof(rsdp->OemId));
  70     buf[sizeof(rsdp->OemId)] = '\0';
  71     setenv("hint.acpi.0.oem", buf, 1);
  72     sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress);
  73     setenv("hint.acpi.0.rsdt", buf, 1);
  74     if (revision >= 2) {
  75         /* XXX extended checksum? */
  76         sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress);
  77         setenv("hint.acpi.0.xsdt", buf, 1);
  78         sprintf(buf, "%d", rsdp->Length);
  79         setenv("hint.acpi.0.xsdt_length", buf, 1);
  80     }
  81     /* XXX other tables? */
  82
  83     setenv("acpi_load", "YES", 1);
  84 }
  85
  86 /*
  87  * Find the RSDP in low memory.  See section 5.2.2 of the ACPI spec.
  88  */
  89 static RSDP_DESCRIPTOR *
  90 biosacpi_find_rsdp(void)
  91 {
  92     RSDP_DESCRIPTOR     *rsdp;
  93     uint16_t            *addr;
  94
  95     /* EBDA is the 1 KB addressed by the 16 bit pointer at 0x40E. */
  96     addr = (uint16_t *)0x40E;
  97     if ((rsdp = biosacpi_search_rsdp((char *)(*addr << 4), 0x400)) != 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 RSDP_DESCRIPTOR *
 108 biosacpi_search_rsdp(char *base, int length)
 109 {
 110     RSDP_DESCRIPTOR     *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 = (RSDP_DESCRIPTOR *)(base + ofs);
 117
 118         /* compare signature, validate checksum */
 119         if (!strncmp(rsdp->Signature, RSDP_SIG, strlen(RSDP_SIG))) {
 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                 printf("acpi: bad RSDP checksum (%d)\n", sum);
 126                 continue;
 127             }
 128             return(rsdp);
 129         }
 130     }
 131     return(NULL);
 132 }