grub-core/lib/cmos_datetime.c

   1 /* kern/cmos_datetime.c - CMOS datetime function.
   2  *
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2008,2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/datetime.h>
  21 #include <grub/cmos.h>
  22 #include <grub/dl.h>
  23
  24 GRUB_MOD_LICENSE ("GPLv3+");
  25
  26 #if !defined (__powerpc__) && !defined (__sparc__)
  27 #define grub_get_datetime_cmos grub_get_datetime
  28 #define grub_set_datetime_cmos grub_set_datetime
  29 #endif
  30
  31 grub_err_t
  32 grub_get_datetime_cmos (struct grub_datetime *datetime)
  33 {
  34   int is_bcd, is_12hour;
  35   grub_uint8_t value, flag;
  36   grub_err_t err;
  37
  38   err = grub_cmos_read (GRUB_CMOS_INDEX_STATUS_B, &flag);
  39   if (err)
  40     return err;
  41
  42   is_bcd = ! (flag & GRUB_CMOS_STATUS_B_BINARY);
  43
  44   err = grub_cmos_read (GRUB_CMOS_INDEX_YEAR, &value);
  45   if (err)
  46     return err;
  47   if (is_bcd)
  48     value = grub_bcd_to_num (value);
  49
  50   datetime->year = value;
  51   datetime->year += (value < 80) ? 2000 : 1900;
  52
  53   err = grub_cmos_read (GRUB_CMOS_INDEX_MONTH, &value);
  54   if (err)
  55     return err;
  56   if (is_bcd)
  57     value = grub_bcd_to_num (value);
  58
  59   datetime->month = value;
  60
  61   err = grub_cmos_read (GRUB_CMOS_INDEX_DAY_OF_MONTH, &value);
  62   if (err)
  63     return err;
  64   if (is_bcd)
  65     value = grub_bcd_to_num (value);
  66
  67   datetime->day = value;
  68
  69   is_12hour = ! (flag & GRUB_CMOS_STATUS_B_24HOUR);
  70
  71   err = grub_cmos_read (GRUB_CMOS_INDEX_HOUR, &value);
  72   if (err)
  73     return err;
  74   if (is_12hour)
  75     {
  76       is_12hour = (value & 0x80);
  77
  78       value &= 0x7F;
  79       value--;
  80     }
  81
  82   if (is_bcd)
  83     value = grub_bcd_to_num (value);
  84
  85   if (is_12hour)
  86     value += 12;
  87
  88   datetime->hour = value;
  89
  90   err = grub_cmos_read (GRUB_CMOS_INDEX_MINUTE, &value);
  91   if (err)
  92     return err;
  93
  94   if (is_bcd)
  95     value = grub_bcd_to_num (value);
  96
  97   datetime->minute = value;
  98
  99   err = grub_cmos_read (GRUB_CMOS_INDEX_SECOND, &value);
 100   if (err)
 101     return err;
 102   if (is_bcd)
 103     value = grub_bcd_to_num (value);
 104
 105   datetime->second = value;
 106
 107   return 0;
 108 }
 109
 110 grub_err_t
 111 grub_set_datetime_cmos (struct grub_datetime *datetime)
 112 {
 113   int is_bcd, is_12hour;
 114   grub_uint8_t value, flag;
 115   grub_err_t err;
 116
 117   err = grub_cmos_read (GRUB_CMOS_INDEX_STATUS_B, &flag);
 118   if (err)
 119     return err;
 120
 121   is_bcd = ! (flag & GRUB_CMOS_STATUS_B_BINARY);
 122
 123   value = ((datetime->year >= 2000) ? datetime->year - 2000 :
 124            datetime->year - 1900);
 125
 126   if (is_bcd)
 127     value = grub_num_to_bcd (value);
 128
 129   err = grub_cmos_write (GRUB_CMOS_INDEX_YEAR, value);
 130   if (err)
 131     return err;
 132
 133   value = datetime->month;
 134
 135   if (is_bcd)
 136     value = grub_num_to_bcd (value);
 137
 138   err = grub_cmos_write (GRUB_CMOS_INDEX_MONTH, value);
 139   if (err)
 140     return err;
 141
 142   value = datetime->day;
 143
 144   if (is_bcd)
 145     value = grub_num_to_bcd (value);
 146
 147   err = grub_cmos_write (GRUB_CMOS_INDEX_DAY_OF_MONTH, value);
 148   if (err)
 149     return err;
 150
 151   value = datetime->hour;
 152
 153   is_12hour = (! (flag & GRUB_CMOS_STATUS_B_24HOUR));
 154
 155   if (is_12hour)
 156     {
 157       value++;
 158
 159       if (value > 12)
 160         value -= 12;
 161       else
 162         is_12hour = 0;
 163     }
 164
 165   if (is_bcd)
 166     value = grub_num_to_bcd (value);
 167
 168   if (is_12hour)
 169     value |= 0x80;
 170
 171   err = grub_cmos_write (GRUB_CMOS_INDEX_HOUR, value);
 172   if (err)
 173     return err;
 174
 175   value = datetime->minute;
 176
 177   if (is_bcd)
 178     value = grub_num_to_bcd (value);
 179
 180   err = grub_cmos_write (GRUB_CMOS_INDEX_MINUTE, value);
 181   if (err)
 182     return err;
 183
 184   value = datetime->second;
 185
 186   if (is_bcd)
 187     value = grub_num_to_bcd (value);
 188
 189   err = grub_cmos_write (GRUB_CMOS_INDEX_SECOND, value);
 190   if (err)
 191     return err;
 192
 193   return 0;
 194 }