103 lines
2.8 KiB
C
103 lines
2.8 KiB
C
|
/* rdmsr.c - Read CPU model-specific registers. */
|
||
|
|
/*
|
||
|
|
* GRUB -- GRand Unified Bootloader
|
||
|
|
* Copyright (C) 2019 Free Software Foundation, Inc.
|
||
|
|
* Based on gcc/gcc/config/i386/driver-i386.c
|
||
|
|
*
|
||
|
|
* GRUB is free software: you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation, either version 3 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* GRUB is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <grub/dl.h>
|
||
|
|
#include <grub/misc.h>
|
||
|
|
#include <grub/mm.h>
|
||
|
|
#include <grub/env.h>
|
||
|
|
#include <grub/command.h>
|
||
|
|
#include <grub/extcmd.h>
|
||
|
|
#include <grub/i18n.h>
|
||
|
|
#include <grub/i386/cpuid.h>
|
||
|
|
#include <grub/i386/rdmsr.h>
|
||
|
|
|
||
|
|
GRUB_MOD_LICENSE("GPLv3+");
|
||
|
|
|
||
|
|
static grub_extcmd_t cmd_read;
|
||
|
|
|
||
|
|
static const struct grub_arg_option options[] =
|
||
|
|
{
|
||
|
|
{0, 'v', 0, N_("Save read value into variable VARNAME."),
|
||
|
|
N_("VARNAME"), ARG_TYPE_STRING},
|
||
|
|
{0, 0, 0, 0, 0, 0}
|
||
|
|
};
|
||
|
|
|
||
|
|
static grub_err_t
|
||
|
|
grub_cmd_msr_read (grub_extcmd_context_t ctxt, int argc, char **argv)
|
||
|
|
{
|
||
|
|
grub_uint32_t manufacturer[3], max_cpuid, a, b, c, features, addr;
|
||
|
|
grub_uint64_t value;
|
||
|
|
char *ptr;
|
||
|
|
char buf[sizeof("1122334455667788")];
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The CPUID instruction should be used to determine whether MSRs
|
||
|
|
* are supported. (CPUID.01H:EDX[5] = 1)
|
||
|
|
*/
|
||
|
|
if (! grub_cpu_is_cpuid_supported ())
|
||
|
|
return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
|
||
|
|
|
||
|
|
grub_cpuid (0, max_cpuid, manufacturer[0], manufacturer[2], manufacturer[1]);
|
||
|
|
|
||
|
|
if (max_cpuid < 1)
|
||
|
|
return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
|
||
|
|
|
||
|
|
grub_cpuid (1, a, b, c, features);
|
||
|
|
|
||
|
|
if (!(features & (1 << 5)))
|
||
|
|
return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
|
||
|
|
|
||
|
|
if (argc != 1)
|
||
|
|
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
|
||
|
|
|
||
|
|
grub_errno = GRUB_ERR_NONE;
|
||
|
|
ptr = argv[0];
|
||
|
|
addr = grub_strtoul (ptr, &ptr, 0);
|
||
|
|
|
||
|
|
if (grub_errno != GRUB_ERR_NONE)
|
||
|
|
return grub_errno;
|
||
|
|
if (*ptr != '\0')
|
||
|
|
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
|
||
|
|
|
||
|
|
value = grub_msr_read (addr);
|
||
|
|
|
||
|
|
if (ctxt->state[0].set)
|
||
|
|
{
|
||
|
|
grub_snprintf (buf, sizeof(buf), "%llx", (unsigned long long) value);
|
||
|
|
grub_env_set (ctxt->state[0].arg, buf);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
grub_printf ("0x%llx\n", (unsigned long long) value);
|
||
|
|
|
||
|
|
return GRUB_ERR_NONE;
|
||
|
|
}
|
||
|
|
|
||
|
|
GRUB_MOD_INIT(rdmsr)
|
||
|
|
{
|
||
|
|
cmd_read = grub_register_extcmd ("rdmsr", grub_cmd_msr_read, 0, N_("ADDR"),
|
||
|
|
N_("Read a CPU model specific register."),
|
||
|
|
options);
|
||
|
|
}
|
||
|
|
|
||
|
|
GRUB_MOD_FINI(rdmsr)
|
||
|
|
{
|
||
|
|
grub_unregister_extcmd (cmd_read);
|
||
|
|
}
|