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|
// SPDX-License-Identifier: GPL-2.0+
/*
* EFI boot manager
*
* Copyright (c) 2017 Rob Clark
*/
#define LOG_CATEGORY LOGC_EFI
#include <common.h>
#include <charset.h>
#include <log.h>
#include <malloc.h>
#include <efi_default_filename.h>
#include <efi_loader.h>
#include <efi_variable.h>
#include <asm/unaligned.h>
static const struct efi_boot_services *bs;
static const struct efi_runtime_services *rs;
const efi_guid_t efi_guid_bootmenu_auto_generated =
EFICONFIG_AUTO_GENERATED_ENTRY_GUID;
/*
* bootmgr implements the logic of trying to find a payload to boot
* based on the BootOrder + BootXXXX variables, and then loading it.
*
* TODO detecting a special key held (f9?) and displaying a boot menu
* like you would get on a PC would be clever.
*
* TODO if we had a way to write and persist variables after the OS
* has started, we'd also want to check OsIndications to see if we
* should do normal or recovery boot.
*/
/**
* expand_media_path() - expand a device path for default file name
* @device_path: device path to check against
*
* If @device_path is a media or disk partition which houses a file
* system, this function returns a full device path which contains
* an architecture-specific default file name for removable media.
*
* Return: a newly allocated device path
*/
static
struct efi_device_path *expand_media_path(struct efi_device_path *device_path)
{
struct efi_device_path *rem, *full_path;
efi_handle_t handle;
if (!device_path)
return NULL;
/*
* If device_path is a (removable) media or partition which provides
* simple file system protocol, append a default file name to support
* booting from removable media.
*/
handle = efi_dp_find_obj(device_path,
&efi_simple_file_system_protocol_guid, &rem);
if (handle) {
if (rem->type == DEVICE_PATH_TYPE_END) {
full_path = efi_dp_from_file(device_path,
"/EFI/BOOT/" BOOTEFI_NAME);
} else {
full_path = efi_dp_dup(device_path);
}
} else {
full_path = efi_dp_dup(device_path);
}
return full_path;
}
/**
* try_load_from_file_path() - try to load a file
*
* Given a file media path iterate through a list of handles and try to
* to load the file from each of them until the first success.
*
* @fs_handles: array of handles with the simple file protocol
* @num: number of handles in fs_handles
* @fp: file path to open
* @handle: on return pointer to handle for loaded image
* @removable: if true only consider removable media, else only non-removable
*/
static efi_status_t try_load_from_file_path(efi_handle_t *fs_handles,
efi_uintn_t num,
struct efi_device_path *fp,
efi_handle_t *handle,
bool removable)
{
struct efi_handler *handler;
struct efi_device_path *dp;
int i;
efi_status_t ret;
for (i = 0; i < num; i++) {
if (removable != efi_disk_is_removable(fs_handles[i]))
continue;
ret = efi_search_protocol(fs_handles[i], &efi_guid_device_path,
&handler);
if (ret != EFI_SUCCESS)
continue;
dp = handler->protocol_interface;
if (!dp)
continue;
dp = efi_dp_append(dp, fp);
if (!dp)
continue;
ret = EFI_CALL(efi_load_image(true, efi_root, dp, NULL, 0,
handle));
efi_free_pool(dp);
if (ret == EFI_SUCCESS)
return ret;
}
return EFI_NOT_FOUND;
}
/**
* try_load_from_short_path
* @fp: file path
* @handle: pointer to handle for newly installed image
*
* Enumerate all the devices which support file system operations,
* prepend its media device path to the file path, @fp, and
* try to load the file.
* This function should be called when handling a short-form path
* which is starting with a file device path.
*
* Return: status code
*/
static efi_status_t try_load_from_short_path(struct efi_device_path *fp,
efi_handle_t *handle)
{
efi_handle_t *fs_handles;
efi_uintn_t num;
efi_status_t ret;
ret = EFI_CALL(efi_locate_handle_buffer(
BY_PROTOCOL,
&efi_simple_file_system_protocol_guid,
NULL,
&num, &fs_handles));
if (ret != EFI_SUCCESS)
return ret;
if (!num)
return EFI_NOT_FOUND;
/* removable media first */
ret = try_load_from_file_path(fs_handles, num, fp, handle, true);
if (ret == EFI_SUCCESS)
goto out;
/* fixed media */
ret = try_load_from_file_path(fs_handles, num, fp, handle, false);
if (ret == EFI_SUCCESS)
goto out;
out:
return ret;
}
/**
* try_load_entry() - try to load image for boot option
*
* Attempt to load load-option number 'n', returning device_path and file_path
* if successful. This checks that the EFI_LOAD_OPTION is active (enabled)
* and that the specified file to boot exists.
*
* @n: number of the boot option, e.g. 0x0a13 for Boot0A13
* @handle: on return handle for the newly installed image
* @load_options: load options set on the loaded image protocol
* Return: status code
*/
static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
void **load_options)
{
struct efi_load_option lo;
u16 varname[9];
void *load_option;
efi_uintn_t size;
efi_status_t ret;
efi_create_indexed_name(varname, sizeof(varname), "Boot", n);
load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
if (!load_option)
return EFI_LOAD_ERROR;
ret = efi_deserialize_load_option(&lo, load_option, &size);
if (ret != EFI_SUCCESS) {
log_warning("Invalid load option for %ls\n", varname);
goto error;
}
if (lo.attributes & LOAD_OPTION_ACTIVE) {
struct efi_device_path *file_path;
u32 attributes;
log_debug("trying to load \"%ls\" from %pD\n", lo.label,
lo.file_path);
if (EFI_DP_TYPE(lo.file_path, MEDIA_DEVICE, FILE_PATH)) {
/* file_path doesn't contain a device path */
ret = try_load_from_short_path(lo.file_path, handle);
} else {
file_path = expand_media_path(lo.file_path);
ret = EFI_CALL(efi_load_image(true, efi_root, file_path,
NULL, 0, handle));
efi_free_pool(file_path);
}
if (ret != EFI_SUCCESS) {
log_warning("Loading %ls '%ls' failed\n",
varname, lo.label);
goto error;
}
attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS;
ret = efi_set_variable_int(u"BootCurrent",
&efi_global_variable_guid,
attributes, sizeof(n), &n, false);
if (ret != EFI_SUCCESS)
goto unload;
/* try to register load file2 for initrd's */
if (IS_ENABLED(CONFIG_EFI_LOAD_FILE2_INITRD)) {
ret = efi_initrd_register();
if (ret != EFI_SUCCESS)
goto unload;
}
log_info("Booting: %ls\n", lo.label);
} else {
ret = EFI_LOAD_ERROR;
}
/* Set load options */
if (size >= sizeof(efi_guid_t) &&
!guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated))
size = 0;
if (size) {
*load_options = malloc(size);
if (!*load_options) {
ret = EFI_OUT_OF_RESOURCES;
goto error;
}
memcpy(*load_options, lo.optional_data, size);
ret = efi_set_load_options(*handle, size, *load_options);
} else {
*load_options = NULL;
}
error:
free(load_option);
return ret;
unload:
if (EFI_CALL(efi_unload_image(*handle)) != EFI_SUCCESS)
log_err("Unloading image failed\n");
free(load_option);
return ret;
}
/**
* efi_bootmgr_load() - try to load from BootNext or BootOrder
*
* Attempt to load from BootNext or in the order specified by BootOrder
* EFI variable, the available load-options, finding and returning
* the first one that can be loaded successfully.
*
* @handle: on return handle for the newly installed image
* @load_options: load options set on the loaded image protocol
* Return: status code
*/
efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options)
{
u16 bootnext, *bootorder;
efi_uintn_t size;
int i, num;
efi_status_t ret;
bs = systab.boottime;
rs = systab.runtime;
/* BootNext */
size = sizeof(bootnext);
ret = efi_get_variable_int(u"BootNext",
&efi_global_variable_guid,
NULL, &size, &bootnext, NULL);
if (ret == EFI_SUCCESS || ret == EFI_BUFFER_TOO_SMALL) {
/* BootNext does exist here */
if (ret == EFI_BUFFER_TOO_SMALL || size != sizeof(u16))
log_err("BootNext must be 16-bit integer\n");
/* delete BootNext */
ret = efi_set_variable_int(u"BootNext",
&efi_global_variable_guid,
0, 0, NULL, false);
/* load BootNext */
if (ret == EFI_SUCCESS) {
if (size == sizeof(u16)) {
ret = try_load_entry(bootnext, handle,
load_options);
if (ret == EFI_SUCCESS)
return ret;
log_warning(
"Loading from BootNext failed, falling back to BootOrder\n");
}
} else {
log_err("Deleting BootNext failed\n");
}
}
/* BootOrder */
bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
if (!bootorder) {
log_info("BootOrder not defined\n");
ret = EFI_NOT_FOUND;
goto error;
}
num = size / sizeof(uint16_t);
for (i = 0; i < num; i++) {
log_debug("trying to load Boot%04X\n", bootorder[i]);
ret = try_load_entry(bootorder[i], handle, load_options);
if (ret == EFI_SUCCESS)
break;
}
free(bootorder);
error:
return ret;
}
/**
* efi_bootmgr_enumerate_boot_option() - enumerate the possible bootable media
*
* @opt: pointer to the media boot option structure
* @volume_handles: pointer to the efi handles
* @count: number of efi handle
* Return: status code
*/
static efi_status_t efi_bootmgr_enumerate_boot_option(struct eficonfig_media_boot_option *opt,
efi_handle_t *volume_handles,
efi_status_t count)
{
u32 i;
struct efi_handler *handler;
efi_status_t ret = EFI_SUCCESS;
for (i = 0; i < count; i++) {
u16 *p;
u16 dev_name[BOOTMENU_DEVICE_NAME_MAX];
char *optional_data;
struct efi_load_option lo;
char buf[BOOTMENU_DEVICE_NAME_MAX];
struct efi_device_path *device_path;
struct efi_device_path *short_dp;
ret = efi_search_protocol(volume_handles[i], &efi_guid_device_path, &handler);
if (ret != EFI_SUCCESS)
continue;
ret = efi_protocol_open(handler, (void **)&device_path,
efi_root, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
if (ret != EFI_SUCCESS)
continue;
ret = efi_disk_get_device_name(volume_handles[i], buf, BOOTMENU_DEVICE_NAME_MAX);
if (ret != EFI_SUCCESS)
continue;
p = dev_name;
utf8_utf16_strncpy(&p, buf, strlen(buf));
/* prefer to short form device path */
short_dp = efi_dp_shorten(device_path);
if (short_dp)
device_path = short_dp;
lo.label = dev_name;
lo.attributes = LOAD_OPTION_ACTIVE;
lo.file_path = device_path;
lo.file_path_length = efi_dp_size(device_path) + sizeof(END);
/*
* Set the dedicated guid to optional_data, it is used to identify
* the boot option that automatically generated by the bootmenu.
* efi_serialize_load_option() expects optional_data is null-terminated
* utf8 string, so set the "1234567" string to allocate enough space
* to store guid, instead of realloc the load_option.
*/
lo.optional_data = "1234567";
opt[i].size = efi_serialize_load_option(&lo, (u8 **)&opt[i].lo);
if (!opt[i].size) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
/* set the guid */
optional_data = (char *)opt[i].lo + (opt[i].size - u16_strsize(u"1234567"));
memcpy(optional_data, &efi_guid_bootmenu_auto_generated, sizeof(efi_guid_t));
}
out:
return ret;
}
/**
* efi_bootmgr_delete_invalid_boot_option() - delete non-existing boot option
*
* @opt: pointer to the media boot option structure
* @count: number of media boot option structure
* Return: status code
*/
static efi_status_t efi_bootmgr_delete_invalid_boot_option(struct eficonfig_media_boot_option *opt,
efi_status_t count)
{
efi_uintn_t size;
void *load_option;
u32 i, list_size = 0;
struct efi_load_option lo;
u16 *var_name16 = NULL;
u16 varname[] = u"Boot####";
efi_status_t ret = EFI_SUCCESS;
u16 *delete_index_list = NULL, *p;
efi_uintn_t buf_size;
buf_size = 128;
var_name16 = malloc(buf_size);
if (!var_name16)
return EFI_OUT_OF_RESOURCES;
var_name16[0] = 0;
for (;;) {
int index;
efi_guid_t guid;
efi_uintn_t tmp;
ret = efi_next_variable_name(&buf_size, &var_name16, &guid);
if (ret == EFI_NOT_FOUND) {
/*
* EFI_NOT_FOUND indicates we retrieved all EFI variables.
* This should be treated as success.
*/
ret = EFI_SUCCESS;
break;
}
if (ret != EFI_SUCCESS)
goto out;
if (!efi_varname_is_load_option(var_name16, &index))
continue;
efi_create_indexed_name(varname, sizeof(varname), "Boot", index);
load_option = efi_get_var(varname, &efi_global_variable_guid, &size);
if (!load_option)
continue;
tmp = size;
ret = efi_deserialize_load_option(&lo, load_option, &size);
if (ret != EFI_SUCCESS)
goto next;
if (size >= sizeof(efi_guid_bootmenu_auto_generated) &&
!guidcmp(lo.optional_data, &efi_guid_bootmenu_auto_generated)) {
for (i = 0; i < count; i++) {
if (opt[i].size == tmp &&
memcmp(opt[i].lo, load_option, tmp) == 0) {
opt[i].exist = true;
break;
}
}
/*
* The entire list of variables must be retrieved by
* efi_get_next_variable_name_int() before deleting the invalid
* boot option, just save the index here.
*/
if (i == count) {
p = realloc(delete_index_list, sizeof(u32) *
(list_size + 1));
if (!p) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
delete_index_list = p;
delete_index_list[list_size++] = index;
}
}
next:
free(load_option);
}
/* delete all invalid boot options */
for (i = 0; i < list_size; i++) {
ret = efi_bootmgr_delete_boot_option(delete_index_list[i]);
if (ret != EFI_SUCCESS)
goto out;
}
out:
free(var_name16);
free(delete_index_list);
return ret;
}
/**
* efi_bootmgr_get_unused_bootoption() - get unused "Boot####" index
*
* @buf: pointer to the buffer to store boot option variable name
* @buf_size: buffer size
* @index: pointer to store the index in the BootOrder variable
* Return: status code
*/
efi_status_t efi_bootmgr_get_unused_bootoption(u16 *buf, efi_uintn_t buf_size,
unsigned int *index)
{
u32 i;
efi_status_t ret;
efi_uintn_t size;
if (buf_size < u16_strsize(u"Boot####"))
return EFI_BUFFER_TOO_SMALL;
for (i = 0; i <= 0xFFFF; i++) {
size = 0;
efi_create_indexed_name(buf, buf_size, "Boot", i);
ret = efi_get_variable_int(buf, &efi_global_variable_guid,
NULL, &size, NULL, NULL);
if (ret == EFI_BUFFER_TOO_SMALL)
continue;
else
break;
}
if (i > 0xFFFF)
return EFI_OUT_OF_RESOURCES;
*index = i;
return EFI_SUCCESS;
}
/**
* efi_bootmgr_append_bootorder() - append new boot option in BootOrder variable
*
* @index: "Boot####" index to append to BootOrder variable
* Return: status code
*/
efi_status_t efi_bootmgr_append_bootorder(u16 index)
{
u16 *bootorder;
efi_status_t ret;
u16 *new_bootorder = NULL;
efi_uintn_t last, size, new_size;
/* append new boot option */
bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
last = size / sizeof(u16);
new_size = size + sizeof(u16);
new_bootorder = calloc(1, new_size);
if (!new_bootorder) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
memcpy(new_bootorder, bootorder, size);
new_bootorder[last] = index;
ret = efi_set_variable_int(u"BootOrder", &efi_global_variable_guid,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
new_size, new_bootorder, false);
if (ret != EFI_SUCCESS)
goto out;
out:
free(bootorder);
free(new_bootorder);
return ret;
}
/**
* efi_bootmgr_delete_boot_option() - delete selected boot option
*
* @boot_index: boot option index to delete
* Return: status code
*/
efi_status_t efi_bootmgr_delete_boot_option(u16 boot_index)
{
u16 *bootorder;
u16 varname[9];
efi_status_t ret;
unsigned int index;
efi_uintn_t num, size;
efi_create_indexed_name(varname, sizeof(varname),
"Boot", boot_index);
ret = efi_set_variable_int(varname, &efi_global_variable_guid,
0, 0, NULL, false);
if (ret != EFI_SUCCESS) {
log_err("delete boot option(%ls) failed\n", varname);
return ret;
}
/* update BootOrder if necessary */
bootorder = efi_get_var(u"BootOrder", &efi_global_variable_guid, &size);
if (!bootorder)
return EFI_SUCCESS;
num = size / sizeof(u16);
if (!efi_search_bootorder(bootorder, num, boot_index, &index))
return EFI_SUCCESS;
memmove(&bootorder[index], &bootorder[index + 1],
(num - index - 1) * sizeof(u16));
size -= sizeof(u16);
ret = efi_set_variable_int(u"BootOrder", &efi_global_variable_guid,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
size, bootorder, false);
return ret;
}
/**
* efi_bootmgr_update_media_device_boot_option() - generate the media device boot option
*
* This function enumerates all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
* and generate the bootmenu entries.
* This function also provide the BOOT#### variable maintenance for
* the media device entries.
* - Automatically create the BOOT#### variable for the newly detected device,
* this BOOT#### variable is distinguished by the special GUID
* stored in the EFI_LOAD_OPTION.optional_data
* - If the device is not attached to the system, the associated BOOT#### variable
* is automatically deleted.
*
* Return: status code
*/
efi_status_t efi_bootmgr_update_media_device_boot_option(void)
{
u32 i;
efi_status_t ret;
efi_uintn_t count;
efi_handle_t *volume_handles = NULL;
struct eficonfig_media_boot_option *opt = NULL;
ret = efi_locate_handle_buffer_int(BY_PROTOCOL,
&efi_simple_file_system_protocol_guid,
NULL, &count,
(efi_handle_t **)&volume_handles);
if (ret != EFI_SUCCESS)
goto out;
opt = calloc(count, sizeof(struct eficonfig_media_boot_option));
if (!opt) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
/* enumerate all devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL */
ret = efi_bootmgr_enumerate_boot_option(opt, volume_handles, count);
if (ret != EFI_SUCCESS)
goto out;
/*
* System hardware configuration may vary depending on the user setup.
* The boot option is automatically added by the bootmenu.
* If the device is not attached to the system, the boot option needs
* to be deleted.
*/
ret = efi_bootmgr_delete_invalid_boot_option(opt, count);
if (ret != EFI_SUCCESS)
goto out;
/* add non-existent boot option */
for (i = 0; i < count; i++) {
u32 boot_index;
u16 var_name[9];
if (!opt[i].exist) {
ret = efi_bootmgr_get_unused_bootoption(var_name, sizeof(var_name),
&boot_index);
if (ret != EFI_SUCCESS)
goto out;
ret = efi_set_variable_int(var_name, &efi_global_variable_guid,
EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
opt[i].size, opt[i].lo, false);
if (ret != EFI_SUCCESS)
goto out;
ret = efi_bootmgr_append_bootorder(boot_index);
if (ret != EFI_SUCCESS) {
efi_set_variable_int(var_name, &efi_global_variable_guid,
0, 0, NULL, false);
goto out;
}
}
}
out:
if (opt) {
for (i = 0; i < count; i++)
free(opt[i].lo);
}
free(opt);
efi_free_pool(volume_handles);
if (ret == EFI_NOT_FOUND)
return EFI_SUCCESS;
return ret;
}
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