com32/sysdump/acpi.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2010 Intel Corporation; author: H. Peter Anvin
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
   8  *   Boston MA 02110-1301, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 /*
  14  * Dump ACPI information
  15  */
  16
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <stdlib.h>
  20 #include "sysdump.h"
  21 #include "backend.h"
  22
  23 struct acpi_rsdp {
  24     uint8_t  magic[8];          /* "RSD PTR " */
  25     uint8_t  csum;
  26     char     oemid[6];
  27     uint8_t  rev;
  28     uint32_t rsdt_addr;
  29     uint32_t len;
  30     uint64_t xdst_addr;
  31     uint8_t  xcsum;
  32     uint8_t  rsvd[3];
  33 };
  34
  35 struct acpi_hdr {
  36     char     sig[4];            /* Signature */
  37     uint32_t len;
  38     uint8_t  rev;
  39     uint8_t  csum;
  40     char     oemid[6];
  41     char     oemtblid[16];
  42     uint32_t oemrev;
  43     uint32_t creatorid;
  44     uint32_t creatorrev;
  45 };
  46
  47 struct acpi_rsdt {
  48     struct acpi_hdr hdr;
  49     uint32_t entry[0];
  50 };
  51
  52 enum tbl_errs {
  53     ERR_NONE,                   /* No errors */
  54     ERR_CSUM,                   /* Invalid checksum */
  55     ERR_SIZE,                   /* Impossibly large table */
  56     ERR_NOSIG                   /* No signature */
  57 };
  58
  59 static uint8_t checksum_range(const void *start, uint32_t size)
  60 {
  61     const uint8_t *p = start;
  62     uint8_t csum = 0;
  63
  64     while (size--)
  65         csum += *p++;
  66
  67     return csum;
  68 }
  69
  70 static enum tbl_errs is_valid_table(const void *ptr)
  71 {
  72     const struct acpi_hdr *hdr = ptr;
  73
  74     if (hdr->sig[0] == 0)
  75         return ERR_NOSIG;
  76
  77     if (hdr->len < 10 || hdr->len > (1 << 20)) {
  78         /* Either insane or too large to dump */
  79         return ERR_SIZE;
  80     }
  81
  82     return checksum_range(hdr, hdr->len) == 0 ? ERR_NONE : ERR_CSUM;
  83 }
  84
  85 static const struct acpi_rsdp *scan_for_rsdp(uint32_t base, uint32_t end)
  86 {
  87     for (base &= ~15; base < end-20; base += 16) {
  88         const struct acpi_rsdp *rsdp = (const struct acpi_rsdp *)base;
  89
  90         if (memcmp(rsdp->magic, "RSD PTR ", 8))
  91             continue;
  92
  93         if (checksum_range(rsdp, 20))
  94             continue;
  95
  96         if (rsdp->rev > 0) {
  97             if (base + rsdp->len >= end ||
  98                 checksum_range(rsdp, rsdp->len))
  99                 continue;
 100         }
 101
 102         return rsdp;
 103     }
 104
 105     return NULL;
 106 }
 107
 108 static const struct acpi_rsdp *find_rsdp(void)
 109 {
 110     uint32_t ebda;
 111     const struct acpi_rsdp *rsdp;
 112
 113     ebda = (*(uint16_t *)0x40e) << 4;
 114     if (ebda >= 0x70000 && ebda < 0xa0000) {
 115         rsdp = scan_for_rsdp(ebda, ebda+1024);
 116
 117         if (rsdp)
 118             return rsdp;
 119     }
 120
 121     return scan_for_rsdp(0xe0000, 0x100000);
 122 }
 123
 124 static void dump_table(struct backend *be,
 125                        const char name[], const void *ptr, uint32_t len)
 126 {
 127     char namebuf[64];
 128
 129     /* XXX: this make cause the same directory to show up more than once */
 130     snprintf(namebuf, sizeof namebuf, "acpi/%4.4s", name);
 131     cpio_mkdir(be, namebuf);
 132
 133     snprintf(namebuf, sizeof namebuf, "acpi/%4.4s/%08x", name, (uint32_t)ptr);
 134     cpio_hdr(be, MODE_FILE, len, namebuf);
 135
 136     write_data(be, ptr, len);
 137 }
 138
 139 void dump_acpi(struct backend *be)
 140 {
 141     const struct acpi_rsdp *rsdp;
 142     const struct acpi_rsdt *rsdt;
 143     uint32_t rsdp_len;
 144     uint32_t i, n;
 145
 146     rsdp = find_rsdp();
 147
 148     if (!rsdp)
 149         return;                 /* No ACPI information found */
 150
 151     cpio_mkdir(be, "acpi");
 152
 153     rsdp_len = rsdp->rev > 0 ? rsdp->len : 20;
 154
 155     dump_table(be, "RSDP", rsdp, rsdp_len);
 156
 157     rsdt = (const struct acpi_rsdt *)rsdp->rsdt_addr;
 158
 159     if (memcmp(rsdt->hdr.sig, "RSDT", 4) || is_valid_table(rsdt) != ERR_NONE)
 160         return;
 161
 162     dump_table(be, rsdt->hdr.sig, rsdt, rsdt->hdr.len);
 163
 164     if (rsdt->hdr.len < 36)
 165         return;
 166
 167     n = (rsdt->hdr.len - 36) >> 2;
 168
 169     for (i = 0; i < n; i++) {
 170         const struct acpi_hdr *hdr = (const struct acpi_hdr *)(rsdt->entry[i]);
 171
 172         if (is_valid_table(hdr) <= ERR_CSUM)
 173             dump_table(be, hdr->sig, hdr, hdr->len);
 174     }
 175 }