grub-core/kern/acpi.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2012  Free Software Foundation, Inc.
   4  *
   5  *  GRUB 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, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/types.h>
  20 #include <grub/time.h>
  21 #include <grub/misc.h>
  22 #include <grub/acpi.h>
  23
  24 /* Simple checksum by summing all bytes. Used by ACPI and SMBIOS. */
  25 grub_uint8_t
  26 grub_byte_checksum (void *base, grub_size_t size)
  27 {
  28   grub_uint8_t *ptr;
  29   grub_uint8_t ret = 0;
  30   for (ptr = (grub_uint8_t *) base; ptr < ((grub_uint8_t *) base) + size;
  31        ptr++)
  32     ret += *ptr;
  33   return ret;
  34 }
  35
  36 static void *
  37 grub_acpi_rsdt_find_table (struct grub_acpi_table_header *rsdt, const char *sig)
  38 {
  39   grub_size_t s;
  40   grub_unaligned_uint32_t *ptr;
  41
  42   if (!rsdt)
  43     return 0;
  44
  45   if (grub_memcmp (rsdt->signature, "RSDT", 4) != 0)
  46     return 0;
  47
  48   ptr = (grub_unaligned_uint32_t *) (rsdt + 1);
  49   s = (rsdt->length - sizeof (*rsdt)) / sizeof (grub_uint32_t);
  50   for (; s; s--, ptr++)
  51     {
  52       struct grub_acpi_table_header *tbl;
  53       tbl = (struct grub_acpi_table_header *) (grub_addr_t) ptr->val;
  54       if (grub_memcmp (tbl->signature, sig, 4) == 0)
  55         return tbl;
  56     }
  57   return 0;
  58 }
  59
  60 static void *
  61 grub_acpi_xsdt_find_table (struct grub_acpi_table_header *xsdt, const char *sig)
  62 {
  63   grub_size_t s;
  64   grub_unaligned_uint64_t *ptr;
  65
  66   if (!xsdt)
  67     return 0;
  68
  69   if (grub_memcmp (xsdt->signature, "XSDT", 4) != 0)
  70     return 0;
  71
  72   ptr = (grub_unaligned_uint64_t *) (xsdt + 1);
  73   s = (xsdt->length - sizeof (*xsdt)) / sizeof (grub_uint32_t);
  74   for (; s; s--, ptr++)
  75     {
  76       struct grub_acpi_table_header *tbl;
  77 #if GRUB_CPU_SIZEOF_VOID_P != 8
  78       if (ptr->val >> 32)
  79         continue;
  80 #endif
  81       tbl = (struct grub_acpi_table_header *) (grub_addr_t) ptr->val;
  82       if (grub_memcmp (tbl->signature, sig, 4) == 0)
  83         return tbl;
  84     }
  85   return 0;
  86 }
  87
  88 struct grub_acpi_fadt *
  89 grub_acpi_find_fadt (void)
  90 {
  91   struct grub_acpi_fadt *fadt = 0;
  92   struct grub_acpi_rsdp_v10 *rsdpv1;
  93   struct grub_acpi_rsdp_v20 *rsdpv2;
  94   rsdpv1 = grub_machine_acpi_get_rsdpv1 ();
  95   if (rsdpv1)
  96     fadt = grub_acpi_rsdt_find_table ((struct grub_acpi_table_header *)
  97                                       (grub_addr_t) rsdpv1->rsdt_addr,
  98                                       GRUB_ACPI_FADT_SIGNATURE);
  99   if (fadt)
 100     return fadt;
 101   rsdpv2 = grub_machine_acpi_get_rsdpv2 ();
 102   if (rsdpv2)
 103     fadt = grub_acpi_rsdt_find_table ((struct grub_acpi_table_header *)
 104                                       (grub_addr_t) rsdpv2->rsdpv1.rsdt_addr,
 105                                       GRUB_ACPI_FADT_SIGNATURE);
 106   if (fadt)
 107     return fadt;
 108   if (rsdpv2
 109 #if GRUB_CPU_SIZEOF_VOID_P != 8
 110       && !(rsdpv2->xsdt_addr >> 32)
 111 #endif
 112       )
 113     fadt = grub_acpi_xsdt_find_table ((struct grub_acpi_table_header *)
 114                                       (grub_addr_t) rsdpv2->xsdt_addr,
 115                                       GRUB_ACPI_FADT_SIGNATURE);
 116   if (fadt)
 117     return fadt;
 118   return 0;
 119 }