u-boot/cmd/bootefi.c
Alexander Graf 0f4060ebcb efi_loader: Pass proper device path in on boot
EFI payloads can query for the device they were booted from. Because
we have a disconnect between loading binaries and running binaries,
we passed in a dummy device path so far.

Unfortunately that breaks grub2's logic to find its configuration
file from the same device it was booted from.

This patch adds logic to have the "load" command call into our efi
code to set the device path to the one we last loaded a binary from.

With this grub2 properly detects where we got booted from and can
find its configuration file, even when searching by-partition.

Signed-off-by: Alexander Graf <agraf@suse.de>
2016-03-15 21:30:14 -04:00

207 lines
5.5 KiB
C

/*
* 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_image_path[] = {
{
.dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
.dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
.dp.length = sizeof(bootefi_image_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_image_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_image_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_image_path,
.file_path = bootefi_image_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_image_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_image_path,
.protocols = {
{
/* When asking for the device path interface, return
* bootefi_image_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;
bootm_headers_t img = { 0 };
/*
* 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) {
/* Prepare fdt for payload */
if (image_setup_libfdt(&img, working_fdt, 0, NULL)) {
printf("ERROR: Failed to process device tree\n");
return -EINVAL;
}
/* Link to it in the efi tables */
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;
}
#ifdef CONFIG_SYS_LONGHELP
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";
#endif
U_BOOT_CMD(
bootefi, 2, 0, do_bootefi,
"Boots an EFI payload from memory\n",
bootefi_help_text
);
void efi_set_bootdev(const char *dev, const char *devnr)
{
char devname[16] = { 0 }; /* dp->str is u16[16] long */
char *colon;
/* Assemble the condensed device name we use in efi_disk.c */
snprintf(devname, sizeof(devname), "%s%s", dev, devnr);
colon = strchr(devname, ':');
if (colon)
*colon = '\0';
/* Patch the bootefi_image_path to the target device */
memset(bootefi_image_path[0].str, 0, sizeof(bootefi_image_path[0].str));
ascii2unicode(bootefi_image_path[0].str, devname);
}