In order to execute an EFI application, we need to bridge the gap between U-Boot's notion of executing images and EFI's notion of doing the same.
The best path forward IMHO here is to stick completely to the way U-Boot deals with payloads. You manually load them using whatever method to RAM and then have a simple boot command to execute them. So in our case, you would do
# load mmc 0:1 $loadaddr grub.efi # bootefi $loadaddr
which then gets you into a grub shell. Fdt information known to U-boot via the fdt addr command is also passed to the EFI payload.
Signed-off-by: Alexander Graf agraf@suse.de Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org
---
v1 -> v2:
- Move to GPLv2+
v2 -> v3:
- Move to new cmd directory - Add kconfig option - Fix comment style - Add help text - s/-1/-ENOENT - Move obj list to lib
v4 -> v5:
- Mark fdt memory as boot services data
v5 -> v6:
- Reserve 2 additional pages for fdt
--- cmd/Kconfig | 7 +++ cmd/Makefile | 1 + cmd/bootefi.c | 180 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 188 insertions(+) create mode 100644 cmd/bootefi.c
diff --git a/cmd/Kconfig b/cmd/Kconfig index 2ed0263..7cdff04 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -148,6 +148,13 @@ config CMD_BOOTM help Boot an application image from the memory.
+config CMD_BOOTEFI + bool "bootefi" + depends on EFI_LOADER + default y + help + Boot an EFI image from memory. + config CMD_ELF bool "bootelf, bootvx" default y diff --git a/cmd/Makefile b/cmd/Makefile index 03f7e0a..7604621 100644 --- a/cmd/Makefile +++ b/cmd/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_CMD_SOURCE) += source.o obj-$(CONFIG_CMD_BDI) += bdinfo.o obj-$(CONFIG_CMD_BEDBUG) += bedbug.o obj-$(CONFIG_CMD_BMP) += bmp.o +obj-$(CONFIG_CMD_BOOTEFI) += bootefi.o obj-$(CONFIG_CMD_BOOTMENU) += bootmenu.o obj-$(CONFIG_CMD_BOOTLDR) += bootldr.o obj-$(CONFIG_CMD_BOOTSTAGE) += bootstage.o diff --git a/cmd/bootefi.c b/cmd/bootefi.c new file mode 100644 index 0000000..38a1b46 --- /dev/null +++ b/cmd/bootefi.c @@ -0,0 +1,180 @@ +/* + * EFI application loader + * + * Copyright (c) 2016 Alexander Graf + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <command.h> +#include <efi_loader.h> +#include <errno.h> +#include <libfdt.h> +#include <libfdt_env.h> + +/* + * When booting using the "bootefi" command, we don't know which + * physical device the file came from. So we create a pseudo-device + * called "bootefi" with the device path /bootefi. + * + * In addition to the originating device we also declare the file path + * of "bootefi" based loads to be /bootefi. + */ +static struct efi_device_path_file_path bootefi_dummy_path[] = { + { + .dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE, + .dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH, + .dp.length = sizeof(bootefi_dummy_path[0]), + .str = { 'b','o','o','t','e','f','i' }, + }, { + .dp.type = DEVICE_PATH_TYPE_END, + .dp.sub_type = DEVICE_PATH_SUB_TYPE_END, + .dp.length = sizeof(bootefi_dummy_path[0]), + } +}; + +static efi_status_t bootefi_open_dp(void *handle, efi_guid_t *protocol, + void **protocol_interface, void *agent_handle, + void *controller_handle, uint32_t attributes) +{ + *protocol_interface = bootefi_dummy_path; + return EFI_SUCCESS; +} + +/* The EFI loaded_image interface for the image executed via "bootefi" */ +static struct efi_loaded_image loaded_image_info = { + .device_handle = bootefi_dummy_path, + .file_path = bootefi_dummy_path, +}; + +/* The EFI object struct for the image executed via "bootefi" */ +static struct efi_object loaded_image_info_obj = { + .handle = &loaded_image_info, + .protocols = { + { + /* + * When asking for the loaded_image interface, just + * return handle which points to loaded_image_info + */ + .guid = &efi_guid_loaded_image, + .open = &efi_return_handle, + }, + { + /* + * When asking for the device path interface, return + * bootefi_dummy_path + */ + .guid = &efi_guid_device_path, + .open = &bootefi_open_dp, + }, + }, +}; + +/* The EFI object struct for the device the "bootefi" image was loaded from */ +static struct efi_object bootefi_device_obj = { + .handle = bootefi_dummy_path, + .protocols = { + { + /* When asking for the device path interface, return + * bootefi_dummy_path */ + .guid = &efi_guid_device_path, + .open = &bootefi_open_dp, + } + }, +}; + +/* + * Load an EFI payload into a newly allocated piece of memory, register all + * EFI objects it would want to access and jump to it. + */ +static unsigned long do_bootefi_exec(void *efi) +{ + ulong (*entry)(void *image_handle, struct efi_system_table *st); + ulong fdt_pages, fdt_size, fdt_start, fdt_end; + + /* + * gd lives in a fixed register which may get clobbered while we execute + * the payload. So save it here and restore it on every callback entry + */ + efi_save_gd(); + + /* Update system table to point to our currently loaded FDT */ + + if (working_fdt) { + systab.tables[0].guid = EFI_FDT_GUID; + systab.tables[0].table = working_fdt; + systab.nr_tables = 1; + + /* And reserve the space in the memory map */ + fdt_start = ((ulong)working_fdt) & ~EFI_PAGE_MASK; + fdt_end = ((ulong)working_fdt) + fdt_totalsize(working_fdt); + fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK; + fdt_pages = fdt_size >> EFI_PAGE_SHIFT; + /* Give a bootloader the chance to modify the device tree */ + fdt_pages += 2; + efi_add_memory_map(fdt_start, fdt_pages, + EFI_BOOT_SERVICES_DATA, true); + + } else { + printf("WARNING: No device tree loaded, expect boot to fail\n"); + systab.nr_tables = 0; + } + + /* Load the EFI payload */ + entry = efi_load_pe(efi, &loaded_image_info); + if (!entry) + return -ENOENT; + + /* Initialize and populate EFI object list */ + INIT_LIST_HEAD(&efi_obj_list); + list_add_tail(&loaded_image_info_obj.link, &efi_obj_list); + list_add_tail(&bootefi_device_obj.link, &efi_obj_list); +#ifdef CONFIG_PARTITIONS + efi_disk_register(); +#endif + + /* Call our payload! */ +#ifdef DEBUG_EFI + printf("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry); +#endif + return entry(&loaded_image_info, &systab); +} + + +/* Interpreter command to boot an arbitrary EFI image from memory */ +static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{ + char *saddr; + unsigned long addr; + int r = 0; + + if (argc < 2) + return 1; + saddr = argv[1]; + + addr = simple_strtoul(saddr, NULL, 16); + + printf("## Starting EFI application at 0x%08lx ...\n", addr); + r = do_bootefi_exec((void *)addr); + printf("## Application terminated, r = %d\n", r); + + if (r != 0) + r = 1; + + return r; +} + +static char bootefi_help_text[] = + "<image address>\n" + " - boot EFI payload stored at address <image address>\n" + "\n" + "Since most EFI payloads want to have a device tree provided, please\n" + "make sure you load a device tree using the fdt addr command before\n" + "executing bootefi.\n"; + +U_BOOT_CMD( + bootefi, 2, 0, do_bootefi, + "Boots an EFI payload from memory\n", + bootefi_help_text +);