grub-core/commands/iorw.c

   1 /* memrw.c - command to read / write physical memory  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 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/dl.h>
  21 #include <grub/misc.h>
  22 #include <grub/extcmd.h>
  23 #include <grub/env.h>
  24 #include <grub/cpu/io.h>
  25 #include <grub/i18n.h>
  26
  27 GRUB_MOD_LICENSE ("GPLv3+");
  28
  29 static grub_extcmd_t cmd_read_byte, cmd_read_word, cmd_read_dword;
  30 static grub_command_t cmd_write_byte, cmd_write_word, cmd_write_dword;
  31
  32 static const struct grub_arg_option options[] =
  33   {
  34     {0, 'v', 0, N_("Save read value into variable VARNAME."),
  35      N_("VARNAME"), ARG_TYPE_STRING},
  36     {0, 0, 0, 0, 0, 0}
  37   };
  38
  39
  40 static grub_err_t
  41 grub_cmd_read (grub_extcmd_context_t ctxt, int argc, char **argv)
  42 {
  43   grub_port_t addr;
  44   grub_uint32_t value = 0;
  45
  46   if (argc != 1)
  47     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
  48
  49   addr = grub_strtoul (argv[0], 0, 0);
  50   switch (ctxt->extcmd->cmd->name[sizeof ("in") - 1])
  51     {
  52     case 'l':
  53       value = grub_inl (addr);
  54       break;
  55
  56     case 'w':
  57       value = grub_inw (addr);
  58       break;
  59
  60     case 'b':
  61       value = grub_inb (addr);
  62       break;
  63     }
  64
  65   if (ctxt->state[0].set)
  66     {
  67       char buf[sizeof ("XXXXXXXX")];
  68       grub_snprintf (buf, sizeof (buf), "%x", value);
  69       grub_env_set (ctxt->state[0].arg, buf);
  70     }
  71   else
  72     grub_printf ("0x%x\n", value);
  73
  74   return 0;
  75 }
  76
  77 static grub_err_t
  78 grub_cmd_write (grub_command_t cmd, int argc, char **argv)
  79 {
  80   grub_port_t addr;
  81   grub_uint32_t value;
  82   grub_uint32_t mask = 0xffffffff;
  83
  84   if (argc != 2 && argc != 3)
  85     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
  86
  87   addr = grub_strtoul (argv[0], 0, 0);
  88   value = grub_strtoul (argv[1], 0, 0);
  89   if (argc == 3)
  90     mask = grub_strtoul (argv[2], 0, 0);
  91   value &= mask;
  92   switch (cmd->name[sizeof ("out") - 1])
  93     {
  94     case 'l':
  95       if (mask != 0xffffffff)
  96         grub_outl ((grub_inl (addr) & ~mask) | value, addr);
  97       else
  98         grub_outl (value, addr);
  99       break;
 100
 101     case 'w':
 102       if ((mask & 0xffff) != 0xffff)
 103         grub_outw ((grub_inw (addr) & ~mask) | value, addr);
 104       else
 105         grub_outw (value, addr);
 106       break;
 107
 108     case 'b':
 109       if ((mask & 0xff) != 0xff)
 110         grub_outb ((grub_inb (addr) & ~mask) | value, addr);
 111       else
 112         grub_outb (value, addr);
 113       break;
 114     }
 115
 116   return 0;
 117 }
 118
 119 GRUB_MOD_INIT(memrw)
 120 {
 121   cmd_read_byte =
 122     grub_register_extcmd ("inb", grub_cmd_read, 0,
 123                           N_("PORT"), N_("Read 8-bit value from PORT."),
 124                           options);
 125   cmd_read_word =
 126     grub_register_extcmd ("inw", grub_cmd_read, 0,
 127                           N_("PORT"), N_("Read 16-bit value from PORT."),
 128                           options);
 129   cmd_read_dword =
 130     grub_register_extcmd ("inl", grub_cmd_read, 0,
 131                           N_("PORT"), N_("Read 32-bit value from PORT."),
 132                           options);
 133   cmd_write_byte =
 134     grub_register_command ("outb", grub_cmd_write,
 135                            N_("PORT VALUE [MASK]"),
 136                            N_("Write 8-bit VALUE to PORT."));
 137   cmd_write_word =
 138     grub_register_command ("outw", grub_cmd_write,
 139                            N_("PORT VALUE [MASK]"),
 140                            N_("Write 16-bit VALUE to PORT."));
 141   cmd_write_dword =
 142     grub_register_command ("outl", grub_cmd_write,
 143                            N_("ADDR VALUE [MASK]"),
 144                            N_("Write 32-bit VALUE to PORT."));
 145 }
 146
 147 GRUB_MOD_FINI(memrw)
 148 {
 149   grub_unregister_extcmd (cmd_read_byte);
 150   grub_unregister_extcmd (cmd_read_word);
 151   grub_unregister_extcmd (cmd_read_dword);
 152   grub_unregister_command (cmd_write_byte);
 153   grub_unregister_command (cmd_write_word);
 154   grub_unregister_command (cmd_write_dword);
 155 }