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setup_var.c
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setup_var.c
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/* setup_var.c - InsydeH2o Setup variable modification tool, can modify single
* bytes within the Setup variable */
/* (c) 2009 by Bernhard Froemel
* (c) 2021 by datasone (patches after setup_var_3)
*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2003,2005,2006,2007,2008,2009,2008 Free Software Foundation, Inc.
*
* 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/types.h>
#include <grub/dl.h>
#include <grub/misc.h>
#include <grub/command.h>
#include <grub/file.h>
#include <grub/efi/efi.h>
#include <grub/pci.h>
#define INSYDE_SETUP_VAR ((grub_efi_char16_t*)"S\0e\0t\0u\0p\0\0\0")
#define INSYDE_SETUP_VAR_NSIZE (12)
#define INSYDE_CUSTOM_VAR ((grub_efi_char16_t*)"C\0u\0s\0t\0o\0m\0\0\0")
#define INSYDE_CUSTOM_VAR_NSIZE (14)
#define INSYDE_SETUP_VAR_SIZE (0x2bc)
#define INSYDE_SETUP_VAR_GUID { 0xa04a27f4, 0xdf00, 0x4d42, { 0xb5, 0x52, 0x39, 0x51, 0x13, 0x02, 0x11, 0x3d } }
#define MAX_VARIABLE_SIZE (1024)
#define MAX_VAR_DATA_SIZE (65536)
#define CMDNAME_SETUP_VAR2 ("setup_var2")
#define CMDCHECK_SETUP_VAR2 (9)
#define CMDCHECK_SETUP_DVARS_START_INDEX (10)
#define CMDNAME_SETUP_VAR3 ("setup_var_3")
#define CMDCHECK_SETUP_VAR3 ("3")
#define CMDNAME_SETUP_VAR_VS ("setup_var_vs")
#define CMDCHECK_SETUP_VAR_VS ("vs")
#define CMDNAME_SETUP_VAR_CV ("setup_var_cv")
#define CMDCHECK_SETUP_VAR_CV ("cv")
#define SETUP_VAR_SIZE_THRESHOLD (0x10)
GRUB_MOD_LICENSE("GPLv3+");
void print_varname(grub_efi_char16_t* str);
void print_varname(grub_efi_char16_t* str)
{
while(*str != 0x0)
{
grub_printf("%c", (grub_uint8_t) *str);
str++;
}
}
grub_uint64_t pack_data(grub_uint8_t* data, grub_uint16_t offset, grub_uint16_t size);
grub_uint64_t pack_data(grub_uint8_t* data, grub_uint16_t offset, grub_uint16_t size)
{
grub_uint64_t res = 0, buf = 0;
for (int i = offset + size - 1; i >= offset; --i) {
buf = data[i];
res += buf << 8 * (i - offset);
}
return res;
}
void set_data(grub_uint8_t* data, grub_uint16_t offset, grub_uint16_t size, grub_uint64_t value);
void set_data(grub_uint8_t* data, grub_uint16_t offset, grub_uint16_t size, grub_uint64_t value)
{
for (int i = offset; i < offset + size; ++i) {
data[i] = (value >> 8 * (i - offset)) & 0xFF;
}
}
static grub_err_t
grub_cmd_setup_var (grub_command_t cmd,
int argc, char *argv[])
{
grub_efi_status_t status;
grub_efi_guid_t setup_var_guid = INSYDE_SETUP_VAR_GUID;
grub_efi_guid_t guid;
grub_uint8_t tmp_data[MAX_VAR_DATA_SIZE];
grub_uint16_t offset = 0x1af;
grub_efi_uintn_t setup_var_size = INSYDE_SETUP_VAR_SIZE;
grub_uint8_t set_value = 0x0;
grub_efi_uint32_t setup_var_attr = 0x7;
const char* endptr;
grub_uint16_t var_size = 0;
grub_efi_char16_t* custom_varname = NULL;
grub_efi_uintn_t custom_varname_size = 0;
grub_efi_char16_t name[MAX_VARIABLE_SIZE/2];
grub_efi_uintn_t name_size;
grub_uint16_t isMode2 = 0;
grub_uint16_t isMode3 = 0;
grub_uint16_t isModeVS = 0;
grub_uint16_t isModeCV = 0;
if (cmd->name[CMDCHECK_SETUP_VAR2] == '2') isMode2 = 1;
if (grub_strlen(cmd->name) > CMDCHECK_SETUP_DVARS_START_INDEX && cmd->name[CMDCHECK_SETUP_DVARS_START_INDEX] != 0)
{
char name_suffix[11];
grub_strncpy(name_suffix, cmd->name + CMDCHECK_SETUP_DVARS_START_INDEX, 10);
if (!grub_strcmp(name_suffix, CMDCHECK_SETUP_VAR3))
isMode3 = 1;
else if (!grub_strcmp(name_suffix, CMDCHECK_SETUP_VAR_VS))
isModeVS = 1;
else if (!grub_strcmp(name_suffix, CMDCHECK_SETUP_VAR_CV))
isModeCV = 1;
}
if (argc == 0)
{
grub_printf(
"Hello!\n"
);
grub_printf(
"You may brick your InsydeH2o based laptop and need to send it in\n"
);
grub_printf(
"for repair.\n"
);
grub_printf(
"Some vendors (like Sony) are rather slow, and it could get expensive if they\n"
);
grub_printf(
"discover that you used this or similar tools.\nYou should be *very* sure what you do.\n"
);
grub_printf(
"\n\nThis Setup variable modification tool may only work with current (July 2009)\n"
);
grub_printf(
"Insyde H2o based firmware releases. Vendors may decide to lock the EFI\n"
);
grub_printf(
"environment completely out or introduce other security measures.\n"
);
grub_printf(
"Final warning: YOU MAY BRICK YOUR LAPTOP IF YOU USE THIS TOOL - I TAKE N O \n"
);
grub_printf(
"RESPONSIBILITY FOR Y O U R ACTIONS.\n"
);
if (isMode3 || isModeVS || isModeCV)
grub_printf(
"\n\n(c) 2009 by Bernhard Froemel <[email protected]>\n(c) 2021 by datasone <[email protected]>\n"
);
else
grub_printf(
"\n\n(c) 2009 by Bernhard Froemel <[email protected]>\n"
);
}
name[0] = 0x0;
if (isModeCV)
{
int varname_size = grub_strlen(argv[0]) + 1;
custom_varname = (grub_efi_char16_t*) grub_malloc(varname_size * sizeof(grub_efi_char16_t));
for (int i = 0; i < varname_size; ++i)
custom_varname[i] = argv[0][i];
custom_varname_size = varname_size * 2;
grub_printf("Looking for %s variable...\n", argv[0]);
}
else
{
/* scan for Setup variable */
grub_printf("Looking for Setup variable...\n");
}
do
{
name_size = MAX_VARIABLE_SIZE;
status = efi_call_3(grub_efi_system_table->runtime_services->get_next_variable_name,
&name_size,
name,
&guid);
if(status == GRUB_EFI_NOT_FOUND)
{ /* finished traversing VSS */
break;
}
if(status)
{
grub_printf("status: 0x%02x\n", (grub_uint32_t) status);
}
if(! status && (
(!isModeCV && name_size == INSYDE_SETUP_VAR_NSIZE && 0 == grub_memcmp(name, INSYDE_SETUP_VAR, name_size)) ||
(isMode2 && name_size == INSYDE_CUSTOM_VAR_NSIZE && 0 == grub_memcmp(name, INSYDE_CUSTOM_VAR, name_size)) ||
(isModeCV && name_size == custom_varname_size && 0 == grub_memcmp(name, custom_varname, name_size))
))
{
grub_printf("var name: ");
print_varname(name);
grub_printf(", var size: %u, var guid: %08x-%04x-%04x - %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x\n\n",
(grub_uint32_t) name_size,
guid.data1,
guid.data2,
guid.data3,
guid.data4[0], guid.data4[1], guid.data4[2], guid.data4[3], guid.data4[4], guid.data4[5], guid.data4[6], guid.data4[7]
);
if(grub_memcmp(&guid, &setup_var_guid, sizeof(grub_efi_guid_t)) == 0)
{
grub_printf("--> GUID matches expected GUID\n");
}
else
{
grub_printf("--> GUID does not match expected GUID, taking it nevertheless...\n");
grub_memcpy(&setup_var_guid, &guid, sizeof(grub_efi_guid_t));
}
/* obtain current contents of Setup variable */
if(argc >= 1 && argc < 3 + (isModeVS) + (isModeCV * 2))
{
if (isModeCV)
{
grub_errno = 0;
offset = grub_strtoul(argv[1], &endptr, 16);
if(endptr == argv[1] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your second argument. Please provide a hex value (e.g. 0x1af).");
}
}
else
{
grub_errno = 0;
offset = grub_strtoul(argv[0], &endptr, 16);
if(endptr == argv[0] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your first argument. Please provide a hex value (e.g. 0x1af).");
}
}
status = efi_call_5(grub_efi_system_table->runtime_services->get_variable,
name,
&setup_var_guid,
&setup_var_attr,
&setup_var_size,
tmp_data);
if(status == GRUB_EFI_BUFFER_TOO_SMALL)
{
grub_printf("expected a different size of the Setup variable (got %d (0x%x) bytes). Continue with care...\n", (int)setup_var_size, (int)setup_var_size);
status = efi_call_5(grub_efi_system_table->runtime_services->get_variable,
name,
&setup_var_guid,
&setup_var_attr,
&setup_var_size,
tmp_data);
}
if(status)
{
return grub_error(GRUB_ERR_INVALID_COMMAND, "can't get variable using efi (error: 0x%016lx)", status);
}
if (isModeCV)
{
grub_printf("successfully obtained \"%s\" variable from VSS (got %d (0x%x) bytes).\n", argv[0], (int)setup_var_size, (int)setup_var_size);
}
else
{
grub_printf("successfully obtained \"Setup\" variable from VSS (got %d (0x%x) bytes).\n", (int)setup_var_size, (int)setup_var_size);
}
if(offset > setup_var_size)
{
/* When in newly added modes and the Setup variable size is too small(smaller than threshold, 0x10 here), supress the error and continue to the next Setup variable */
if ((isMode3) && setup_var_size < SETUP_VAR_SIZE_THRESHOLD)
{
grub_printf("Too small variable detected, ignoring.\n\n");
continue;
}
return grub_error(GRUB_ERR_BAD_ARGUMENT, "offset is out of range.");
}
if (argc == 2 && isModeVS) // VS with only size param
{
var_size = grub_strtoul(argv[1], &endptr, 16);
if(endptr == argv[1] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your second argument. Please provide a hex value (e.g. 0x01).");
}
grub_printf("offset 0x%02x is: 0x%02lx\n", offset, pack_data(tmp_data, offset, var_size));
}
else if (argc == 3 && isModeCV) // CV with only size param
{
var_size = grub_strtoul(argv[2], &endptr, 16);
if(endptr == argv[2] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your third argument. Please provide a hex value (e.g. 0x01).");
}
grub_printf("offset 0x%02x is: 0x%02lx\n", offset, pack_data(tmp_data, offset, var_size));
}
else
grub_printf("offset 0x%02x is: 0x%02x\n", offset, tmp_data[offset]);
}
/* modify and write Setup variable, if user requests it (old commands) */
if((argc == 2) && !(isModeVS || isModeCV))
{
set_value = grub_strtoul(argv[1], &endptr, 16);
if(endptr == argv[1] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your second argument. Please provide a hex value (e.g. 0x01).");
}
grub_printf("setting offset 0x%02x to 0x%02x\n", offset, set_value);
tmp_data[offset] = set_value;
status = efi_call_5(grub_efi_system_table->runtime_services->set_variable,
name,
&setup_var_guid,
setup_var_attr,
setup_var_size,
tmp_data);
if(status)
{
return grub_error(GRUB_ERR_INVALID_COMMAND, "can't set variable using efi (error: 0x%016lx)", status);
}
}
else if (isModeVS)
{
if (argc == 3) // VS with size and setval
{
var_size = grub_strtoul(argv[1], &endptr, 16);
grub_uint64_t larger_set_value = grub_strtoull(argv[2], &endptr, 16);
if (endptr == argv[2] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your third argument. Please provide a hex value (e.g. 0x01).");
}
grub_printf("setting offset 0x%02x to 0x%02lx\n", offset, larger_set_value);
set_data(tmp_data, offset, var_size, larger_set_value);
status = efi_call_5(grub_efi_system_table->runtime_services->set_variable,
name,
&setup_var_guid,
setup_var_attr,
setup_var_size,
tmp_data);
if(status)
{
return grub_error(GRUB_ERR_INVALID_COMMAND, "can't set variable using efi (error: 0x%016lx)", status);
}
}
}
else if (isModeCV)
{
if (argc == 4) // CV with size and setval
{
var_size = grub_strtoul(argv[2], &endptr, 16);
grub_uint64_t larger_set_value = grub_strtoull(argv[3], &endptr, 16);
if (endptr == argv[3] || grub_errno != 0)
{
return grub_error(GRUB_ERR_BAD_ARGUMENT, "can't decode your fourth argument. Please provide a hex value (e.g. 0x01).");
}
grub_printf("setting offset 0x%02x to 0x%02lx\n", offset, larger_set_value);
set_data(tmp_data, offset, var_size, larger_set_value);
status = efi_call_5(grub_efi_system_table->runtime_services->set_variable,
name,
&setup_var_guid,
setup_var_attr,
setup_var_size,
tmp_data);
if(status)
{
return grub_error(GRUB_ERR_INVALID_COMMAND, "can't set variable using efi (error: 0x%016lx)", status);
}
}
}
}
} while (! status);
if(argc == 0 || argc > 2 + (isModeVS) + (isModeCV * 2))
{
if (isModeVS)
return grub_error(GRUB_ERR_BAD_ARGUMENT, "Usage: %s offset [size] [setval]", cmd->name);
if (isModeCV)
return grub_error(GRUB_ERR_BAD_ARGUMENT, "Usage: %s varstorename offset [size] [setval]", cmd->name);
return grub_error(GRUB_ERR_BAD_ARGUMENT, "Usage: %s offset [setval]", cmd->name);
}
grub_free(custom_varname);
return grub_errno;
}
static grub_err_t
grub_cmd_lsefivar (grub_command_t cmd __attribute__ ((unused)),
int argc __attribute__ ((unused)), char *argv[] __attribute__ ((unused)))
{
grub_efi_status_t status;
grub_efi_guid_t guid;
grub_uint8_t tmp_data[MAX_VAR_DATA_SIZE];
grub_efi_uintn_t setup_var_size = INSYDE_SETUP_VAR_SIZE;
grub_efi_uint32_t setup_var_attr = 0x7;
grub_efi_char16_t name[MAX_VARIABLE_SIZE/2];
grub_efi_uintn_t name_size;
name[0] = 0x0;
/* scan for Setup variable */
grub_printf("Listing EFI variables...\n");
do
{
name_size = MAX_VARIABLE_SIZE;
status = efi_call_3(grub_efi_system_table->runtime_services->get_next_variable_name,
&name_size,
name,
&guid);
if(status == GRUB_EFI_NOT_FOUND)
{ /* finished traversing VSS */
break;
}
if(status)
{
grub_printf("status: 0x%02x\n", (grub_uint32_t) status);
}
if(! status)
{
setup_var_size = 1;
status = efi_call_5(grub_efi_system_table->runtime_services->get_variable,
name,
&guid,
&setup_var_attr,
&setup_var_size,
tmp_data);
if (status && status != GRUB_EFI_BUFFER_TOO_SMALL)
{
grub_printf("error (0x%x) getting var size:\n ", (grub_uint32_t)status);
setup_var_size = 0;
}
status = 0;
grub_printf("name size: %02u, var size: %06u (0x%06x), var guid: %08x-%04x-%04x - %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x, name: ",
(grub_uint32_t) name_size, (grub_uint32_t) setup_var_size, (grub_uint32_t) setup_var_size,
guid.data1,
guid.data2,
guid.data3,
guid.data4[0], guid.data4[1], guid.data4[2], guid.data4[3], guid.data4[4], guid.data4[5], guid.data4[6], guid.data4[7]
);
print_varname(name);
grub_printf("\n");
}
} while (! status);
return grub_errno;
}
static grub_command_t cmd_setup_var;
static grub_command_t cmd_setup_var2;
static grub_command_t cmd_setup_var_3;
static grub_command_t cmd_setup_var_vs;
static grub_command_t cmd_setup_var_cv;
static grub_command_t cmd_setup_lsvar;
GRUB_MOD_INIT(setup_var)
{
cmd_setup_var = grub_register_command ("setup_var", grub_cmd_setup_var,
"setup_var offset [setval]",
"Read/Write specific (byte) offset of setup variable.");
cmd_setup_var2 = grub_register_command ("setup_var2", grub_cmd_setup_var,
"setup_var2 offset [setval]",
"Read/Write specific (byte) offset of setup and custom variables.");
cmd_setup_var_3 = grub_register_command ("setup_var_3", grub_cmd_setup_var,
"setup_var_3 offset [setval]",
"Read/Write specific (byte) offset of setup variables ignoring error, use with great caution!!!");
cmd_setup_var_vs = grub_register_command ("setup_var_vs", grub_cmd_setup_var,
"setup_var_vs offset [size] [setval]",
"Read/write specific (byte) offset of setup variable, capable of longer value (specify with size).");
cmd_setup_var_cv = grub_register_command ("setup_var_cv", grub_cmd_setup_var,
"setup_var_cv varstorename offset [size] [setval]",
"Read/write specific (byte) offset of specified variable, capable of longer value (specify with size).");
cmd_setup_lsvar = grub_register_command ("lsefivar", grub_cmd_lsefivar,
"lsefivar",
"Lists all efi variables.");
}
GRUB_MOD_FINI(setup_var)
{
grub_unregister_command (cmd_setup_var);
grub_unregister_command (cmd_setup_var2);
grub_unregister_command (cmd_setup_var_3);
grub_unregister_command (cmd_setup_var_vs);
grub_unregister_command (cmd_setup_var_cv);
grub_unregister_command (cmd_setup_lsvar);
}