[U-Boot] [PATCH 08/14] efi_loader: Add "bootefi" command

Simon Glass
2016-01-31T15:23:16Z

Hi Alexander,

On 14 January 2016 at 22:06, Alexander Graf <agraf@suse.de> wrote:
> 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>
>
> ---
>
> v1 -> v2:
>
> - Move to GPLv2+
> ---
> common/Makefile | 1 +
> common/cmd_bootefi.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 155 insertions(+)
> create mode 100644 common/cmd_bootefi.c

Reviewed-by: Simon Glass <sjg@chromium.org>

>
> diff --git a/common/Makefile b/common/Makefile
> index 2a1d9f8..a7a728a 100644
> --- a/common/Makefile
> +++ b/common/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_CMD_SOURCE) += cmd_source.o
> obj-$(CONFIG_CMD_BDI) += cmd_bdinfo.o
> obj-$(CONFIG_CMD_BEDBUG) += bedbug.o cmd_bedbug.o
> obj-$(CONFIG_CMD_BMP) += cmd_bmp.o
> +obj-$(CONFIG_EFI_LOADER) += cmd_bootefi.o

For mainline this should move to cmd/bootefi.o. Also please add a
Kconfig item for it.

> obj-$(CONFIG_CMD_BOOTMENU) += cmd_bootmenu.o
> obj-$(CONFIG_CMD_BOOTLDR) += cmd_bootldr.o
> obj-$(CONFIG_CMD_BOOTSTAGE) += cmd_bootstage.o
> diff --git a/common/cmd_bootefi.c b/common/cmd_bootefi.c
> new file mode 100644
> index 0000000..fde1942
> --- /dev/null
> +++ b/common/cmd_bootefi.c
> @@ -0,0 +1,154 @@
> +/*
> + * 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 <libfdt_env.h>
> +
> +/* This list contains all the EFI objects our payload has access to */
> +LIST_HEAD(efi_obj_list);
> +
> +/*
> + * 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 */

nit: comment style

> + .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);
> +
> + /*
> + * 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 */
> + systab.tables[0].table = working_fdt;
> +
> + if (!working_fdt) {
> + 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 -1;

-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;
> +}
> +
> +U_BOOT_CMD(
> + bootefi, 2, 0, do_bootefi,
> + "Boot from an EFI image in memory",
> + "<image address>\n"

Could you add any more help here?

> +);
> --
> 2.1.4
>
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Regards,
Simon