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

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

DECLARE_GLOBAL_DATA_PTR;

/*
 * 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 struct efi_device_path_file_path bootefi_device_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 EFIAPI bootefi_open_dp(void *handle, efi_guid_t *protocol,
                        void **protocol_interface, void *agent_handle,
                        void *controller_handle, uint32_t attributes)
{
        *protocol_interface = bootefi_device_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_device_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_device_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_device_path,
        .protocols = {
                {
                        /* When asking for the device path interface, return
                         * bootefi_device_path */
                        .guid = &efi_guid_device_path,
                        .open = &bootefi_open_dp,
                }
        },
};

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, 4096);
        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_BOOT_SERVICES_DATA, fdt_pages,
                               &new_fdt_addr) != EFI_SUCCESS) {
                /* If we can't put it there, put it somewhere */
                new_fdt_addr = (ulong)memalign(4096, fdt_size);
        }
        new_fdt = (void*)(ulong)new_fdt_addr;
        memcpy(new_fdt, fdt, fdt_totalsize(fdt));
        fdt_set_totalsize(new_fdt, fdt_size);

        return new_fdt;
}

#ifdef CONFIG_ARM64
static unsigned long efi_run_in_el2(ulong (*entry)(void *image_handle,
                struct efi_system_table *st), void *image_handle,
                struct efi_system_table *st)
{
        /* Enable caches again */
        dcache_enable();

        return entry(image_handle, st);
}
#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 unsigned long do_bootefi_exec(void *efi, void *fdt)
{
        ulong (*entry)(void *image_handle, struct efi_system_table *st)
                asmlinkage;
        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();

        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 */
                systab.tables[0].guid = EFI_FDT_GUID;
                systab.tables[0].table = fdt;
                systab.nr_tables = 1;

                /* 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");
                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
#ifdef CONFIG_LCD
        efi_gop_register();
#endif
#ifdef CONFIG_NET
        void *nethandle = loaded_image_info.device_handle;
        efi_net_register(&nethandle);

        if (!memcmp(bootefi_device_path[0].str, "N\0e\0t", 6))
                loaded_image_info.device_handle = nethandle;
        else
                loaded_image_info.device_handle = bootefi_device_path;
#endif
#ifdef CONFIG_GENERATE_SMBIOS_TABLE
        efi_smbios_register();
#endif

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

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

        if (setjmp(&loaded_image_info.exit_jmp)) {
                efi_status_t status = loaded_image_info.exit_status;
                return status == EFI_SUCCESS ? 0 : -EINVAL;
        }

#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,
                                    (ulong)&systab, 0, (ulong)efi_run_in_el2,
                                    ES_TO_AARCH64);

                /* Should never reach here, efi exits with longjmp */
                while (1) { }
        }
#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, *sfdt;
        unsigned long addr, fdt_addr = 0;
        int r = 0;

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

                addr = CONFIG_SYS_LOAD_ADDR;
                memcpy((char *)addr, __efi_hello_world_begin, size);
        } else
#endif
        {
                saddr = argv[1];

                addr = simple_strtoul(saddr, NULL, 16);

                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);
        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> [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
        "hello\n"
        "  - boot a sample Hello World application stored within U-Boot"
#endif
        ;
#endif

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

void efi_set_bootdev(const char *dev, const char *devnr, const char *path)
{
        __maybe_unused struct blk_desc *desc;
        char devname[32] = { 0 }; /* dp->str is u16[32] long */
        char *colon;

#if defined(CONFIG_BLK) || defined(CONFIG_ISO_PARTITION)
        desc = blk_get_dev(dev, simple_strtol(devnr, NULL, 10));
#endif

#ifdef CONFIG_BLK
        if (desc) {
                snprintf(devname, sizeof(devname), "%s", desc->bdev->name);
        } else
#endif

        {
                /* Assemble the condensed device name we use in efi_disk.c */
                snprintf(devname, sizeof(devname), "%s%s", dev, devnr);
        }

        colon = strchr(devname, ':');

#ifdef CONFIG_ISO_PARTITION
        /* For ISOs we create partition block devices */
        if (desc && (desc->type != DEV_TYPE_UNKNOWN) &&
            (desc->part_type == PART_TYPE_ISO)) {
                if (!colon)
                        snprintf(devname, sizeof(devname), "%s:1", devname);

                colon = NULL;
        }
#endif

        if (colon)
                *colon = '\0';

        /* Patch bootefi_device_path to the target device */
        memset(bootefi_device_path[0].str, 0, sizeof(bootefi_device_path[0].str));
        ascii2unicode(bootefi_device_path[0].str, devname);

        /* Patch bootefi_image_path to the target file path */
        memset(bootefi_image_path[0].str, 0, sizeof(bootefi_image_path[0].str));
        if (strcmp(dev, "Net")) {
                /* Add leading / to fs paths, because they're absolute */
                snprintf(devname, sizeof(devname), "/%s", path);
        } else {
                snprintf(devname, sizeof(devname), "%s", path);
        }
        ascii2unicode(bootefi_image_path[0].str, devname);
}