// 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 <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);

        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
);