u-boot/cmd/bootefi.c
Ilias Apalodimas 53f6a5aa86 efi_loader: Replace config option for initrd loading
Up to now we install EFI_LOAD_FILE2_PROTOCOL to load an initrd
unconditionally. Although we correctly return various EFI exit codes
depending on the file status (i.e EFI_NO_MEDIA, EFI_NOT_FOUND etc), the
kernel loader, only falls back to the cmdline interpreted initrd if the
protocol is not installed.

This creates a problem for EFI installers, since they won't be able to
load their own initrd and continue the installation. It also makes the
feature hard to use, since we can either have a single initrd or we have
to recompile u-boot if the filename changes.

So let's introduce a different logic that will decouple the initrd
path from the config option we currently have.
When defining a UEFI BootXXXX we can use the filepathlist and store
a file path pointing to our initrd. Specifically the EFI spec describes:

"The first element of the array is a device path that describes the device
and location of the Image for this load option. Other device paths may
optionally exist in the FilePathList, but their usage is OSV specific"

When the EFI application is launched through the bootmgr, we'll try to
interpret the extra device path. If that points to a file that exists on
our disk, we'll now install the load_file2 and the efi-stub will be able
to use it.

This opens up another path using U-Boot and defines a new boot flow.
A user will be able to control the kernel/initrd pairs without explicit
cmdline args or GRUB.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2021-03-25 20:14:26 +01:00

684 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* EFI application loader
*
* Copyright (c) 2016 Alexander Graf
*/
#define LOG_CATEGORY LOGC_EFI
#include <common.h>
#include <bootm.h>
#include <charset.h>
#include <command.h>
#include <dm.h>
#include <efi_loader.h>
#include <efi_selftest.h>
#include <env.h>
#include <errno.h>
#include <image.h>
#include <log.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <linux/libfdt.h>
#include <linux/libfdt_env.h>
#include <mapmem.h>
#include <memalign.h>
#include <asm-generic/sections.h>
#include <linux/linkage.h>
DECLARE_GLOBAL_DATA_PTR;
static struct efi_device_path *bootefi_image_path;
static struct efi_device_path *bootefi_device_path;
static void *image_addr;
static size_t image_size;
/**
* efi_clear_bootdev() - clear boot device
*/
static void efi_clear_bootdev(void)
{
efi_free_pool(bootefi_device_path);
efi_free_pool(bootefi_image_path);
bootefi_device_path = NULL;
bootefi_image_path = NULL;
image_addr = NULL;
image_size = 0;
}
/**
* efi_set_bootdev() - set boot device
*
* This function is called when a file is loaded, e.g. via the 'load' command.
* We use the path to this file to inform the UEFI binary about the boot device.
*
* @dev: device, e.g. "MMC"
* @devnr: number of the device, e.g. "1:2"
* @path: path to file loaded
* @buffer: buffer with file loaded
* @buffer_size: size of file loaded
*/
void efi_set_bootdev(const char *dev, const char *devnr, const char *path,
void *buffer, size_t buffer_size)
{
struct efi_device_path *device, *image;
efi_status_t ret;
/* Forget overwritten image */
if (buffer + buffer_size >= image_addr &&
image_addr + image_size >= buffer)
efi_clear_bootdev();
/* Remember only PE-COFF and FIT images */
if (efi_check_pe(buffer, buffer_size, NULL) != EFI_SUCCESS) {
#ifdef CONFIG_FIT
if (fit_check_format(buffer, IMAGE_SIZE_INVAL))
return;
/*
* FIT images of type EFI_OS are started via command bootm.
* We should not use their boot device with the bootefi command.
*/
buffer = 0;
buffer_size = 0;
#else
return;
#endif
}
/* efi_set_bootdev() is typically called repeatedly, recover memory */
efi_clear_bootdev();
image_addr = buffer;
image_size = buffer_size;
ret = efi_dp_from_name(dev, devnr, path, &device, &image);
if (ret == EFI_SUCCESS) {
bootefi_device_path = device;
if (image) {
/* FIXME: image should not contain device */
struct efi_device_path *image_tmp = image;
efi_dp_split_file_path(image, &device, &image);
efi_free_pool(image_tmp);
}
bootefi_image_path = image;
} else {
efi_clear_bootdev();
}
}
/**
* efi_env_set_load_options() - set load options from environment variable
*
* @handle: the image handle
* @env_var: name of the environment variable
* @load_options: pointer to load options (output)
* Return: status code
*/
static efi_status_t efi_env_set_load_options(efi_handle_t handle,
const char *env_var,
u16 **load_options)
{
const char *env = env_get(env_var);
size_t size;
u16 *pos;
efi_status_t ret;
*load_options = NULL;
if (!env)
return EFI_SUCCESS;
size = sizeof(u16) * (utf8_utf16_strlen(env) + 1);
pos = calloc(size, 1);
if (!pos)
return EFI_OUT_OF_RESOURCES;
*load_options = pos;
utf8_utf16_strcpy(&pos, env);
ret = efi_set_load_options(handle, size, *load_options);
if (ret != EFI_SUCCESS) {
free(*load_options);
*load_options = NULL;
}
return ret;
}
#if !CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
/**
* copy_fdt() - Copy the device tree to a new location available to EFI
*
* The FDT is copied to a suitable location within the EFI memory map.
* Additional 12 KiB are added to the space in case the device tree needs to be
* expanded later with fdt_open_into().
*
* @fdtp: On entry a pointer to the flattened device tree.
* On exit a pointer to the copy of the flattened device tree.
* FDT start
* Return: status code
*/
static efi_status_t copy_fdt(void **fdtp)
{
unsigned long fdt_ram_start = -1L, fdt_pages;
efi_status_t ret = 0;
void *fdt, *new_fdt;
u64 new_fdt_addr;
uint fdt_size;
int i;
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
u64 ram_start = gd->bd->bi_dram[i].start;
u64 ram_size = gd->bd->bi_dram[i].size;
if (!ram_size)
continue;
if (ram_start < fdt_ram_start)
fdt_ram_start = ram_start;
}
/*
* Give us at least 12 KiB of breathing room in case the device tree
* needs to be expanded later.
*/
fdt = *fdtp;
fdt_pages = efi_size_in_pages(fdt_totalsize(fdt) + 0x3000);
fdt_size = fdt_pages << EFI_PAGE_SHIFT;
/*
* Safe fdt location is at 127 MiB.
* On the sandbox convert from the sandbox address space.
*/
new_fdt_addr = (uintptr_t)map_sysmem(fdt_ram_start + 0x7f00000 +
fdt_size, 0);
ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
&new_fdt_addr);
if (ret != EFI_SUCCESS) {
/* If we can't put it there, put it somewhere */
new_fdt_addr = (ulong)memalign(EFI_PAGE_SIZE, fdt_size);
ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
EFI_ACPI_RECLAIM_MEMORY, fdt_pages,
&new_fdt_addr);
if (ret != EFI_SUCCESS) {
log_err("ERROR: Failed to reserve space for FDT\n");
goto done;
}
}
new_fdt = (void *)(uintptr_t)new_fdt_addr;
memcpy(new_fdt, fdt, fdt_totalsize(fdt));
fdt_set_totalsize(new_fdt, fdt_size);
*fdtp = (void *)(uintptr_t)new_fdt_addr;
done:
return ret;
}
/**
* get_config_table() - get configuration table
*
* @guid: GUID of the configuration table
* Return: pointer to configuration table or NULL
*/
static void *get_config_table(const efi_guid_t *guid)
{
size_t i;
for (i = 0; i < systab.nr_tables; i++) {
if (!guidcmp(guid, &systab.tables[i].guid))
return systab.tables[i].table;
}
return NULL;
}
#endif /* !CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE) */
/**
* efi_install_fdt() - install device tree
*
* If fdt is not EFI_FDT_USE_INTERNAL, the device tree located at that memory
* address will will be installed as configuration table, otherwise the device
* tree located at the address indicated by environment variable fdt_addr or as
* fallback fdtcontroladdr will be used.
*
* On architectures using ACPI tables device trees shall not be installed as
* configuration table.
*
* @fdt: address of device tree or EFI_FDT_USE_INTERNAL to use the
* the hardware device tree as indicated by environment variable
* fdt_addr or as fallback the internal device tree as indicated by
* the environment variable fdtcontroladdr
* Return: status code
*/
efi_status_t efi_install_fdt(void *fdt)
{
/*
* The EBBR spec requires that we have either an FDT or an ACPI table
* but not both.
*/
#if CONFIG_IS_ENABLED(GENERATE_ACPI_TABLE)
if (fdt) {
log_err("ERROR: can't have ACPI table and device tree.\n");
return EFI_LOAD_ERROR;
}
#else
bootm_headers_t img = { 0 };
efi_status_t ret;
if (fdt == EFI_FDT_USE_INTERNAL) {
const char *fdt_opt;
uintptr_t fdt_addr;
/* Look for device tree that is already installed */
if (get_config_table(&efi_guid_fdt))
return EFI_SUCCESS;
/* Check if there is a hardware device tree */
fdt_opt = env_get("fdt_addr");
/* Use our own device tree as fallback */
if (!fdt_opt) {
fdt_opt = env_get("fdtcontroladdr");
if (!fdt_opt) {
log_err("ERROR: need device tree\n");
return EFI_NOT_FOUND;
}
}
fdt_addr = simple_strtoul(fdt_opt, NULL, 16);
if (!fdt_addr) {
log_err("ERROR: invalid $fdt_addr or $fdtcontroladdr\n");
return EFI_LOAD_ERROR;
}
fdt = map_sysmem(fdt_addr, 0);
}
/* Install device tree */
if (fdt_check_header(fdt)) {
log_err("ERROR: invalid device tree\n");
return EFI_LOAD_ERROR;
}
/* Prepare device tree for payload */
ret = copy_fdt(&fdt);
if (ret) {
log_err("ERROR: out of memory\n");
return EFI_OUT_OF_RESOURCES;
}
if (image_setup_libfdt(&img, fdt, 0, NULL)) {
log_err("ERROR: failed to process device tree\n");
return EFI_LOAD_ERROR;
}
/* Create memory reservations as indicated by the device tree */
efi_carve_out_dt_rsv(fdt);
/* Install device tree as UEFI table */
ret = efi_install_configuration_table(&efi_guid_fdt, fdt);
if (ret != EFI_SUCCESS) {
log_err("ERROR: failed to install device tree\n");
return ret;
}
#endif /* GENERATE_ACPI_TABLE */
return EFI_SUCCESS;
}
/**
* do_bootefi_exec() - execute EFI binary
*
* The image indicated by @handle is started. When it returns the allocated
* memory for the @load_options is freed.
*
* @handle: handle of loaded image
* @load_options: load options
* Return: status code
*
* Load the EFI binary into a newly assigned memory unwinding the relocation
* information, install the loaded image protocol, and call the binary.
*/
static efi_status_t do_bootefi_exec(efi_handle_t handle, void *load_options)
{
efi_status_t ret;
efi_uintn_t exit_data_size = 0;
u16 *exit_data = NULL;
/* On ARM switch from EL3 or secure mode to EL2 or non-secure mode */
switch_to_non_secure_mode();
/* Call our payload! */
ret = EFI_CALL(efi_start_image(handle, &exit_data_size, &exit_data));
if (ret != EFI_SUCCESS) {
log_err("## Application failed, r = %lu\n",
ret & ~EFI_ERROR_MASK);
if (exit_data) {
log_err("## %ls\n", exit_data);
efi_free_pool(exit_data);
}
}
efi_restore_gd();
free(load_options);
if (IS_ENABLED(CONFIG_EFI_LOAD_FILE2_INITRD))
efi_initrd_deregister();
return ret;
}
/**
* do_efibootmgr() - execute EFI boot manager
*
* Return: status code
*/
static int do_efibootmgr(void)
{
efi_handle_t handle;
efi_status_t ret;
void *load_options;
ret = efi_bootmgr_load(&handle, &load_options);
if (ret != EFI_SUCCESS) {
log_notice("EFI boot manager: Cannot load any image\n");
return CMD_RET_FAILURE;
}
ret = do_bootefi_exec(handle, load_options);
if (ret != EFI_SUCCESS)
return CMD_RET_FAILURE;
return CMD_RET_SUCCESS;
}
/**
* do_bootefi_image() - execute EFI binary
*
* Set up memory image for the binary to be loaded, prepare device path, and
* then call do_bootefi_exec() to execute it.
*
* @image_opt: string of image start address
* Return: status code
*/
static int do_bootefi_image(const char *image_opt)
{
void *image_buf;
unsigned long addr, size;
efi_status_t ret;
#ifdef CONFIG_CMD_BOOTEFI_HELLO
if (!strcmp(image_opt, "hello")) {
image_buf = __efi_helloworld_begin;
size = __efi_helloworld_end - __efi_helloworld_begin;
efi_clear_bootdev();
} else
#endif
{
addr = strtoul(image_opt, NULL, 16);
/* Check that a numeric value was passed */
if (!addr)
return CMD_RET_USAGE;
image_buf = map_sysmem(addr, 0);
if (image_buf != image_addr) {
log_err("No UEFI binary known at %s\n", image_opt);
return CMD_RET_FAILURE;
}
size = image_size;
}
ret = efi_run_image(image_buf, size);
if (ret != EFI_SUCCESS)
return CMD_RET_FAILURE;
return CMD_RET_SUCCESS;
}
/**
* efi_run_image() - run loaded UEFI image
*
* @source_buffer: memory address of the UEFI image
* @source_size: size of the UEFI image
* Return: status code
*/
efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size)
{
efi_handle_t mem_handle = NULL, handle;
struct efi_device_path *file_path = NULL;
struct efi_device_path *msg_path;
efi_status_t ret;
u16 *load_options;
if (!bootefi_device_path || !bootefi_image_path) {
/*
* Special case for efi payload not loaded from disk,
* such as 'bootefi hello' or for example payload
* loaded directly into memory via JTAG, etc:
*/
file_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
(uintptr_t)source_buffer,
source_size);
/*
* Make sure that device for device_path exist
* in load_image(). Otherwise, shell and grub will fail.
*/
ret = efi_create_handle(&mem_handle);
if (ret != EFI_SUCCESS)
goto out;
ret = efi_add_protocol(mem_handle, &efi_guid_device_path,
file_path);
if (ret != EFI_SUCCESS)
goto out;
msg_path = file_path;
} else {
file_path = efi_dp_append(bootefi_device_path,
bootefi_image_path);
msg_path = bootefi_image_path;
}
log_info("Booting %pD\n", msg_path);
ret = EFI_CALL(efi_load_image(false, efi_root, file_path, source_buffer,
source_size, &handle));
if (ret != EFI_SUCCESS) {
log_err("Loading image failed\n");
goto out;
}
/* Transfer environment variable as load options */
ret = efi_env_set_load_options(handle, "bootargs", &load_options);
if (ret != EFI_SUCCESS)
goto out;
ret = do_bootefi_exec(handle, load_options);
out:
efi_delete_handle(mem_handle);
efi_free_pool(file_path);
return ret;
}
#ifdef CONFIG_CMD_BOOTEFI_SELFTEST
static efi_status_t bootefi_run_prepare(const char *load_options_path,
struct efi_device_path *device_path,
struct efi_device_path *image_path,
struct efi_loaded_image_obj **image_objp,
struct efi_loaded_image **loaded_image_infop)
{
efi_status_t ret;
u16 *load_options;
ret = efi_setup_loaded_image(device_path, image_path, image_objp,
loaded_image_infop);
if (ret != EFI_SUCCESS)
return ret;
/* Transfer environment variable as load options */
return efi_env_set_load_options((efi_handle_t)*image_objp,
load_options_path,
&load_options);
}
/**
* bootefi_test_prepare() - prepare to run an EFI test
*
* Prepare to run a test as if it were provided by a loaded image.
*
* @image_objp: pointer to be set to the loaded image handle
* @loaded_image_infop: pointer to be set to the loaded image protocol
* @path: dummy file path used to construct the device path
* set in the loaded image protocol
* @load_options_path: name of a U-Boot environment variable. Its value is
* set as load options in the loaded image protocol.
* Return: status code
*/
static efi_status_t bootefi_test_prepare
(struct efi_loaded_image_obj **image_objp,
struct efi_loaded_image **loaded_image_infop, const char *path,
const char *load_options_path)
{
efi_status_t ret;
/* Construct a dummy device path */
bootefi_device_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE, 0, 0);
if (!bootefi_device_path)
return EFI_OUT_OF_RESOURCES;
bootefi_image_path = efi_dp_from_file(NULL, 0, path);
if (!bootefi_image_path) {
ret = EFI_OUT_OF_RESOURCES;
goto failure;
}
ret = bootefi_run_prepare(load_options_path, bootefi_device_path,
bootefi_image_path, image_objp,
loaded_image_infop);
if (ret == EFI_SUCCESS)
return ret;
failure:
efi_clear_bootdev();
return ret;
}
/**
* bootefi_run_finish() - finish up after running an EFI test
*
* @loaded_image_info: Pointer to a struct which holds the loaded image info
* @image_obj: Pointer to a struct which holds the loaded image object
*/
static void bootefi_run_finish(struct efi_loaded_image_obj *image_obj,
struct efi_loaded_image *loaded_image_info)
{
efi_restore_gd();
free(loaded_image_info->load_options);
efi_delete_handle(&image_obj->header);
}
/**
* do_efi_selftest() - execute EFI selftest
*
* Return: status code
*/
static int do_efi_selftest(void)
{
struct efi_loaded_image_obj *image_obj;
struct efi_loaded_image *loaded_image_info;
efi_status_t ret;
ret = bootefi_test_prepare(&image_obj, &loaded_image_info,
"\\selftest", "efi_selftest");
if (ret != EFI_SUCCESS)
return CMD_RET_FAILURE;
/* Execute the test */
ret = EFI_CALL(efi_selftest(&image_obj->header, &systab));
bootefi_run_finish(image_obj, loaded_image_info);
return ret != EFI_SUCCESS;
}
#endif /* CONFIG_CMD_BOOTEFI_SELFTEST */
/**
* do_bootefi() - execute `bootefi` command
*
* @cmdtp: table entry describing command
* @flag: bitmap indicating how the command was invoked
* @argc: number of arguments
* @argv: command line arguments
* Return: status code
*/
static int do_bootefi(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
efi_status_t ret;
void *fdt;
if (argc < 2)
return CMD_RET_USAGE;
/* Initialize EFI drivers */
ret = efi_init_obj_list();
if (ret != EFI_SUCCESS) {
log_err("Error: Cannot initialize UEFI sub-system, r = %lu\n",
ret & ~EFI_ERROR_MASK);
return CMD_RET_FAILURE;
}
if (argc > 2) {
uintptr_t fdt_addr;
fdt_addr = simple_strtoul(argv[2], NULL, 16);
fdt = map_sysmem(fdt_addr, 0);
} else {
fdt = EFI_FDT_USE_INTERNAL;
}
ret = efi_install_fdt(fdt);
if (ret == EFI_INVALID_PARAMETER)
return CMD_RET_USAGE;
else if (ret != EFI_SUCCESS)
return CMD_RET_FAILURE;
if (IS_ENABLED(CONFIG_CMD_BOOTEFI_BOOTMGR)) {
if (!strcmp(argv[1], "bootmgr"))
return do_efibootmgr();
}
#ifdef CONFIG_CMD_BOOTEFI_SELFTEST
if (!strcmp(argv[1], "selftest"))
return do_efi_selftest();
#endif
return do_bootefi_image(argv[1]);
}
#ifdef CONFIG_SYS_LONGHELP
static char bootefi_help_text[] =
"<image address> [fdt address]\n"
" - boot EFI payload stored at address <image address>.\n"
" If specified, the device tree located at <fdt address> gets\n"
" exposed as EFI configuration table.\n"
#ifdef CONFIG_CMD_BOOTEFI_HELLO
"bootefi hello\n"
" - boot a sample Hello World application stored within U-Boot\n"
#endif
#ifdef CONFIG_CMD_BOOTEFI_SELFTEST
"bootefi selftest [fdt address]\n"
" - boot an EFI selftest application stored within U-Boot\n"
" Use environment variable efi_selftest to select a single test.\n"
" Use 'setenv efi_selftest list' to enumerate all tests.\n"
#endif
#ifdef CONFIG_CMD_BOOTEFI_BOOTMGR
"bootefi bootmgr [fdt address]\n"
" - load and boot EFI payload based on BootOrder/BootXXXX variables.\n"
"\n"
" If specified, the device tree located at <fdt address> gets\n"
" exposed as EFI configuration table.\n"
#endif
;
#endif
U_BOOT_CMD(
bootefi, 3, 0, do_bootefi,
"Boots an EFI payload from memory",
bootefi_help_text
);