diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/efi_loader/Makefile | 2 | ||||
| -rw-r--r-- | lib/efi_loader/efi_bootmgr.c | 180 | ||||
| -rw-r--r-- | lib/efi_loader/efi_boottime.c | 6 | ||||
| -rw-r--r-- | lib/efi_loader/efi_image_loader.c | 1 |
4 files changed, 185 insertions, 4 deletions
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 301bf7b507..ddb978f650 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -17,7 +17,7 @@ endif obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o obj-y += efi_image_loader.o efi_boottime.o efi_runtime.o efi_console.o obj-y += efi_memory.o efi_device_path_to_text.o efi_device_path.o -obj-y += efi_file.o efi_variable.o +obj-y += efi_file.o efi_variable.o efi_bootmgr.o obj-$(CONFIG_LCD) += efi_gop.o obj-$(CONFIG_DM_VIDEO) += efi_gop.o obj-$(CONFIG_PARTITIONS) += efi_disk.o diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c new file mode 100644 index 0000000000..857d88a879 --- /dev/null +++ b/lib/efi_loader/efi_bootmgr.c @@ -0,0 +1,180 @@ +/* + * EFI utils + * + * Copyright (c) 2017 Rob Clark + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <charset.h> +#include <malloc.h> +#include <efi_loader.h> + +static const struct efi_boot_services *bs; +static const struct efi_runtime_services *rs; + +#define LOAD_OPTION_ACTIVE 0x00000001 +#define LOAD_OPTION_FORCE_RECONNECT 0x00000002 +#define LOAD_OPTION_HIDDEN 0x00000008 + +/* + * 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. + */ + + +/* + * See section 3.1.3 in the v2.7 UEFI spec for more details on + * the layout of EFI_LOAD_OPTION. In short it is: + * + * typedef struct _EFI_LOAD_OPTION { + * UINT32 Attributes; + * UINT16 FilePathListLength; + * // CHAR16 Description[]; <-- variable length, NULL terminated + * // EFI_DEVICE_PATH_PROTOCOL FilePathList[]; <-- FilePathListLength bytes + * // UINT8 OptionalData[]; + * } EFI_LOAD_OPTION; + */ +struct load_option { + u32 attributes; + u16 file_path_length; + u16 *label; + struct efi_device_path *file_path; + u8 *optional_data; +}; + +/* parse an EFI_LOAD_OPTION, as described above */ +static void parse_load_option(struct load_option *lo, void *ptr) +{ + lo->attributes = *(u32 *)ptr; + ptr += sizeof(u32); + + lo->file_path_length = *(u16 *)ptr; + ptr += sizeof(u16); + + lo->label = ptr; + ptr += (utf16_strlen(lo->label) + 1) * 2; + + lo->file_path = ptr; + ptr += lo->file_path_length; + + lo->optional_data = ptr; +} + +/* free() the result */ +static void *get_var(u16 *name, const efi_guid_t *vendor, + unsigned long *size) +{ + efi_guid_t *v = (efi_guid_t *)vendor; + efi_status_t ret; + void *buf = NULL; + + *size = 0; + EFI_CALL(ret = rs->get_variable((s16 *)name, v, NULL, size, buf)); + if (ret == EFI_BUFFER_TOO_SMALL) { + buf = malloc(*size); + EFI_CALL(ret = rs->get_variable((s16 *)name, v, NULL, size, buf)); + } + + if (ret != EFI_SUCCESS) { + free(buf); + *size = 0; + return NULL; + } + + return buf; +} + +/* + * 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. + */ +static void *try_load_entry(uint16_t n, struct efi_device_path **device_path, + struct efi_device_path **file_path) +{ + struct load_option lo; + u16 varname[] = L"Boot0000"; + u16 hexmap[] = L"0123456789ABCDEF"; + void *load_option, *image = NULL; + unsigned long size; + + varname[4] = hexmap[(n & 0xf000) >> 12]; + varname[5] = hexmap[(n & 0x0f00) >> 8]; + varname[6] = hexmap[(n & 0x00f0) >> 4]; + varname[7] = hexmap[(n & 0x000f) >> 0]; + + load_option = get_var(varname, &efi_global_variable_guid, &size); + if (!load_option) + return NULL; + + parse_load_option(&lo, load_option); + + if (lo.attributes & LOAD_OPTION_ACTIVE) { + efi_status_t ret; + u16 *str = NULL; + + debug("%s: trying to load \"%ls\" from: %ls\n", __func__, + lo.label, (str = efi_dp_str(lo.file_path))); + efi_free_pool(str); + + ret = efi_load_image_from_path(lo.file_path, &image); + + if (ret != EFI_SUCCESS) + goto error; + + printf("Booting: %ls\n", lo.label); + efi_dp_split_file_path(lo.file_path, device_path, file_path); + } + +error: + free(load_option); + + return image; +} + +/* + * Attempt to load, in the order specified by BootOrder EFI variable, the + * available load-options, finding and returning the first one that can + * be loaded successfully. + */ +void *efi_bootmgr_load(struct efi_device_path **device_path, + struct efi_device_path **file_path) +{ + uint16_t *bootorder; + unsigned long size; + void *image = NULL; + int i, num; + + __efi_entry_check(); + + bs = systab.boottime; + rs = systab.runtime; + + bootorder = get_var(L"BootOrder", &efi_global_variable_guid, &size); + if (!bootorder) + goto error; + + num = size / sizeof(uint16_t); + for (i = 0; i < num; i++) { + debug("%s: trying to load Boot%04X\n", __func__, bootorder[i]); + image = try_load_entry(bootorder[i], device_path, file_path); + if (image) + break; + } + + free(bootorder); + +error: + __efi_exit_check(); + + return image; +} diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index 90f0051484..f97b0ca4ab 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -814,8 +814,8 @@ void efi_setup_loaded_image(struct efi_loaded_image *info, struct efi_object *ob list_add_tail(&obj->link, &efi_obj_list); } -static efi_status_t load_image_from_path(struct efi_device_path *file_path, - void **buffer) +efi_status_t efi_load_image_from_path(struct efi_device_path *file_path, + void **buffer) { struct efi_file_info *info = NULL; struct efi_file_handle *f; @@ -875,7 +875,7 @@ static efi_status_t EFIAPI efi_load_image(bool boot_policy, struct efi_device_path *dp, *fp; efi_status_t ret; - ret = load_image_from_path(file_path, &source_buffer); + ret = efi_load_image_from_path(file_path, &source_buffer); if (ret != EFI_SUCCESS) { free(info); free(obj); diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index 469acae082..242e6a504b 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -15,6 +15,7 @@ DECLARE_GLOBAL_DATA_PTR; +const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID; const efi_guid_t efi_guid_device_path = DEVICE_PATH_GUID; const efi_guid_t efi_guid_loaded_image = LOADED_IMAGE_GUID; const efi_guid_t efi_simple_file_system_protocol_guid = |