/*
 *  EFI application loader
 *
 *  Copyright (c) 2016 Alexander Graf
 *
 *  SPDX-License-Identifier:     GPL-2.0+
 */

#include <charset.h>
#include <common.h>
#include <command.h>
#include <dm.h>
#include <efi_loader.h>
#include <efi_selftest.h>
#include <errno.h>
#include <linux/libfdt.h>
#include <linux/libfdt_env.h>
#include <memalign.h>
#include <asm/global_data.h>
#include <asm-generic/sections.h>
#include <linux/linkage.h>

DECLARE_GLOBAL_DATA_PTR;

static uint8_t efi_obj_list_initalized;

static struct efi_device_path *bootefi_image_path;
static struct efi_device_path *bootefi_device_path;

/* Initialize and populate EFI object list */
static void efi_init_obj_list(void)
{
        efi_obj_list_initalized = 1;

        /* Initialize EFI driver uclass */
        efi_driver_init();

        efi_console_register();
#ifdef CONFIG_PARTITIONS
        efi_disk_register();
#endif
#if defined(CONFIG_LCD) || defined(CONFIG_DM_VIDEO)
        efi_gop_register();
#endif
#ifdef CONFIG_CMD_NET
        efi_net_register();
#endif
#ifdef CONFIG_GENERATE_SMBIOS_TABLE
        efi_smbios_register();
#endif
        efi_watchdog_register();

        /* Initialize EFI runtime services */
        efi_reset_system_init();
        efi_get_time_init();
}

/*
 * Set the load options of an image from an environment variable.
 *
 * @loaded_image_info:  the image
 * @env_var:            name of the environment variable
 */
static void set_load_options(struct efi_loaded_image *loaded_image_info,
                             const char *env_var)
{
        size_t size;
        const char *env = env_get(env_var);

        loaded_image_info->load_options = NULL;
        loaded_image_info->load_options_size = 0;
        if (!env)
                return;
        size = strlen(env) + 1;
        loaded_image_info->load_options = calloc(size, sizeof(u16));
        if (!loaded_image_info->load_options) {
                printf("ERROR: Out of memory\n");
                return;
        }
        utf8_to_utf16(loaded_image_info->load_options, (u8 *)env, size);
        loaded_image_info->load_options_size = size * 2;
}

static void *copy_fdt(void *fdt)
{
        u64 fdt_size = fdt_totalsize(fdt);
        unsigned long fdt_ram_start = -1L, fdt_pages;
        u64 new_fdt_addr;
        void *new_fdt;
        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 4kb breathing room */
        fdt_size = ALIGN(fdt_size + 4096, EFI_PAGE_SIZE);
        fdt_pages = fdt_size >> EFI_PAGE_SHIFT;

        /* Safe fdt location is at 128MB */
        new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
        if (efi_allocate_pages(1, EFI_RUNTIME_SERVICES_DATA, fdt_pages,
                               &new_fdt_addr) != EFI_SUCCESS) {
                /* If we can't put it there, put it somewhere */
                new_fdt_addr = (ulong)memalign(EFI_PAGE_SIZE, fdt_size);
                if (efi_allocate_pages(1, EFI_RUNTIME_SERVICES_DATA, fdt_pages,
                                       &new_fdt_addr) != EFI_SUCCESS) {
                        printf("ERROR: Failed to reserve space for FDT\n");
                        return NULL;
                }
        }

        new_fdt = (void*)(ulong)new_fdt_addr;
        memcpy(new_fdt, fdt, fdt_totalsize(fdt));
        fdt_set_totalsize(new_fdt, fdt_size);

        return new_fdt;
}

static efi_status_t efi_do_enter(
                        efi_handle_t image_handle, struct efi_system_table *st,
                        EFIAPI efi_status_t (*entry)(
                                efi_handle_t image_handle,
                                struct efi_system_table *st))
{
        efi_status_t ret = EFI_LOAD_ERROR;

        if (entry)
                ret = entry(image_handle, st);
        st->boottime->exit(image_handle, ret, 0, NULL);
        return ret;
}

#ifdef CONFIG_ARM64
static efi_status_t efi_run_in_el2(EFIAPI efi_status_t (*entry)(
                        efi_handle_t image_handle, struct efi_system_table *st),
                        efi_handle_t image_handle, struct efi_system_table *st)
{
        /* Enable caches again */
        dcache_enable();

        return efi_do_enter(image_handle, st, entry);
}
#endif

/*
 * 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 efi_status_t do_bootefi_exec(void *efi, void *fdt,
                                    struct efi_device_path *device_path,
                                    struct efi_device_path *image_path)
{
        struct efi_loaded_image loaded_image_info = {};
        struct efi_object loaded_image_info_obj = {};
        struct efi_device_path *memdp = NULL;
        ulong ret;

        EFIAPI efi_status_t (*entry)(efi_handle_t image_handle,
                                     struct efi_system_table *st);
        ulong fdt_pages, fdt_size, fdt_start, fdt_end;
        const efi_guid_t fdt_guid = EFI_FDT_GUID;
        bootm_headers_t img = { 0 };

        /*
         * Special case for efi payload not loaded from disk, such as
         * 'bootefi hello' or for example payload loaded directly into
         * memory via jtag/etc:
         */
        if (!device_path && !image_path) {
                printf("WARNING: using memory device/image path, this may confuse some payloads!\n");
                /* actual addresses filled in after efi_load_pe() */
                memdp = efi_dp_from_mem(0, 0, 0);
                device_path = image_path = memdp;
        } else {
                assert(device_path && image_path);
        }

        /* Initialize and populate EFI object list */
        if (!efi_obj_list_initalized)
                efi_init_obj_list();

        efi_setup_loaded_image(&loaded_image_info, &loaded_image_info_obj,
                               device_path, image_path);

        /*
         * 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();

        if (fdt && !fdt_check_header(fdt)) {
                /* Prepare fdt for payload */
                fdt = copy_fdt(fdt);

                if (image_setup_libfdt(&img, fdt, 0, NULL)) {
                        printf("ERROR: Failed to process device tree\n");
                        return -EINVAL;
                }

                /* Link to it in the efi tables */
                efi_install_configuration_table(&fdt_guid, fdt);

                /* And reserve the space in the memory map */
                fdt_start = ((ulong)fdt) & ~EFI_PAGE_MASK;
                fdt_end = ((ulong)fdt) + fdt_totalsize(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: Invalid device tree, expect boot to fail\n");
                efi_install_configuration_table(&fdt_guid, NULL);
        }

        /* Transfer environment variable bootargs as load options */
        set_load_options(&loaded_image_info, "bootargs");
        /* Load the EFI payload */
        entry = efi_load_pe(efi, &loaded_image_info);
        if (!entry) {
                ret = -ENOENT;
                goto exit;
        }

        if (memdp) {
                struct efi_device_path_memory *mdp = (void *)memdp;
                mdp->memory_type = loaded_image_info.image_code_type;
                mdp->start_address = (uintptr_t)loaded_image_info.image_base;
                mdp->end_address = mdp->start_address +
                                loaded_image_info.image_size;
        }

        /* we don't support much: */
        env_set("efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported",
                "{ro,boot}(blob)0000000000000000");

        /* Call our payload! */
        debug("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry);

        if (setjmp(&loaded_image_info.exit_jmp)) {
                ret = loaded_image_info.exit_status;
                goto exit;
        }

#ifdef CONFIG_ARM64
        /* On AArch64 we need to make sure we call our payload in < EL3 */
        if (current_el() == 3) {
                smp_kick_all_cpus();
                dcache_disable();       /* flush cache before switch to EL2 */

                /* Move into EL2 and keep running there */
                armv8_switch_to_el2((ulong)entry,
                                    (ulong)&loaded_image_info_obj.handle,
                                    (ulong)&systab, 0, (ulong)efi_run_in_el2,
                                    ES_TO_AARCH64);

                /* Should never reach here, efi exits with longjmp */
                while (1) { }
        }
#endif

        ret = efi_do_enter(loaded_image_info_obj.handle, &systab, entry);

exit:
        /* image has returned, loaded-image obj goes *poof*: */
        list_del(&loaded_image_info_obj.link);

        return ret;
}

static int do_bootefi_bootmgr_exec(unsigned long fdt_addr)
{
        struct efi_device_path *device_path, *file_path;
        void *addr;
        efi_status_t r;

        /* Initialize and populate EFI object list */
        if (!efi_obj_list_initalized)
                efi_init_obj_list();

        /*
         * 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();

        addr = efi_bootmgr_load(&device_path, &file_path);
        if (!addr)
                return 1;

        printf("## Starting EFI application at %p ...\n", addr);
        r = do_bootefi_exec(addr, (void *)fdt_addr, device_path, file_path);
        printf("## Application terminated, r = %lu\n",
               r & ~EFI_ERROR_MASK);

        if (r != EFI_SUCCESS)
                return 1;

        return 0;
}

/* 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, *sfdt;
        unsigned long addr, fdt_addr = 0;
        efi_status_t r;

        if (argc < 2)
                return CMD_RET_USAGE;
#ifdef CONFIG_CMD_BOOTEFI_HELLO
        if (!strcmp(argv[1], "hello")) {
                ulong size = __efi_helloworld_end - __efi_helloworld_begin;

                saddr = env_get("loadaddr");
                if (saddr)
                        addr = simple_strtoul(saddr, NULL, 16);
                else
                        addr = CONFIG_SYS_LOAD_ADDR;
                memcpy((char *)addr, __efi_helloworld_begin, size);
        } else
#endif
#ifdef CONFIG_CMD_BOOTEFI_SELFTEST
        if (!strcmp(argv[1], "selftest")) {
                struct efi_loaded_image loaded_image_info = {};
                struct efi_object loaded_image_info_obj = {};

                /* Construct a dummy device path. */
                bootefi_device_path = efi_dp_from_mem(EFI_RESERVED_MEMORY_TYPE,
                                                      (uintptr_t)&efi_selftest,
                                                      (uintptr_t)&efi_selftest);
                bootefi_image_path = efi_dp_from_file(NULL, 0, "\\selftest");

                efi_setup_loaded_image(&loaded_image_info,
                                       &loaded_image_info_obj,
                                       bootefi_device_path, bootefi_image_path);
                /*
                 * 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();
                /* Initialize and populate EFI object list */
                if (!efi_obj_list_initalized)
                        efi_init_obj_list();
                /* Transfer environment variable efi_selftest as load options */
                set_load_options(&loaded_image_info, "efi_selftest");
                /* Execute the test */
                r = efi_selftest(loaded_image_info_obj.handle, &systab);
                efi_restore_gd();
                free(loaded_image_info.load_options);
                list_del(&loaded_image_info_obj.link);
                return r != EFI_SUCCESS;
        } else
#endif
        if (!strcmp(argv[1], "bootmgr")) {
                unsigned long fdt_addr = 0;

                if (argc > 2)
                        fdt_addr = simple_strtoul(argv[2], NULL, 16);

                return do_bootefi_bootmgr_exec(fdt_addr);
        } else {
                saddr = argv[1];

                addr = simple_strtoul(saddr, NULL, 16);
                /* Check that a numeric value was passed */
                if (!addr && *saddr != '0')
                        return CMD_RET_USAGE;

                if (argc > 2) {
                        sfdt = argv[2];
                        fdt_addr = simple_strtoul(sfdt, NULL, 16);
                }
        }

        printf("## Starting EFI application at %08lx ...\n", addr);
        r = do_bootefi_exec((void *)addr, (void *)fdt_addr,
                            bootefi_device_path, bootefi_image_path);
        printf("## Application terminated, r = %lu\n",
               r & ~EFI_ERROR_MASK);

        if (r != EFI_SUCCESS)
                return 1;
        else
                return 0;
}

#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\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
        "bootefi bootmgr [fdt addr]\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

U_BOOT_CMD(
        bootefi, 3, 0, do_bootefi,
        "Boots an EFI payload from memory",
        bootefi_help_text
);

static int parse_partnum(const char *devnr)
{
        const char *str = strchr(devnr, ':');
        if (str) {
                str++;
                return simple_strtoul(str, NULL, 16);
        }
        return 0;
}

void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
{
        char filename[32] = { 0 }; /* dp->str is u16[32] long */
        char *s;

        if (strcmp(dev, "Net")) {
                struct blk_desc *desc;
                int part;

                desc = blk_get_dev(dev, simple_strtol(devnr, NULL, 10));
                if (!desc)
                        return;
                part = parse_partnum(devnr);

                bootefi_device_path = efi_dp_from_part(desc, part);
        } else {
#ifdef CONFIG_CMD_NET
                bootefi_device_path = efi_dp_from_eth();
#endif
        }

        if (!path)
                return;

        if (strcmp(dev, "Net")) {
                /* Add leading / to fs paths, because they're absolute */
                snprintf(filename, sizeof(filename), "/%s", path);
        } else {
                snprintf(filename, sizeof(filename), "%s", path);
        }
        /* DOS style file path: */
        s = filename;
        while ((s = strchr(s, '/')))
                *s++ = '\\';
        bootefi_image_path = efi_dp_from_file(NULL, 0, filename);
}