// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016 Marvell International Ltd.
 * https://spdx.org/licenses
 */

#include <config.h>
#include <common.h>
#include <command.h>
#include <env.h>
#include <flash.h>
#include <image.h>
#include <net.h>
#include <vsprintf.h>
#include <errno.h>
#include <dm.h>

#include <spi_flash.h>
#include <spi.h>
#include <nand.h>
#include <usb.h>
#include <fs.h>
#include <mmc.h>
#ifdef CONFIG_BLK
#include <blk.h>
#endif
#include <u-boot/sha1.h>
#include <u-boot/sha256.h>

#if defined(CONFIG_ARMADA_8K)
#define MAIN_HDR_MAGIC          0xB105B002

struct mvebu_image_header {
        u32     magic;                  /*  0-3  */
        u32     prolog_size;            /*  4-7  */
        u32     prolog_checksum;        /*  8-11 */
        u32     boot_image_size;        /* 12-15 */
        u32     boot_image_checksum;    /* 16-19 */
        u32     rsrvd0;                 /* 20-23 */
        u32     load_addr;              /* 24-27 */
        u32     exec_addr;              /* 28-31 */
        u8      uart_cfg;               /*  32   */
        u8      baudrate;               /*  33   */
        u8      ext_count;              /*  34   */
        u8      aux_flags;              /*  35   */
        u32     io_arg_0;               /* 36-39 */
        u32     io_arg_1;               /* 40-43 */
        u32     io_arg_2;               /* 43-47 */
        u32     io_arg_3;               /* 48-51 */
        u32     rsrvd1;                 /* 52-55 */
        u32     rsrvd2;                 /* 56-59 */
        u32     rsrvd3;                 /* 60-63 */
};
#elif defined(CONFIG_ARMADA_3700)       /* A3700 */
#define HASH_SUM_LEN            16
#define IMAGE_VERSION_3_6_0     0x030600
#define IMAGE_VERSION_3_5_0     0x030500

struct common_tim_data {
        u32     version;
        u32     identifier;
        u32     trusted;
        u32     issue_date;
        u32     oem_unique_id;
        u32     reserved[5];            /* Reserve 20 bytes */
        u32     boot_flash_sign;
        u32     num_images;
        u32     num_keys;
        u32     size_of_reserved;
};

struct mvebu_image_info {
        u32     image_id;
        u32     next_image_id;
        u32     flash_entry_addr;
        u32     load_addr;
        u32     image_size;
        u32     image_size_to_hash;
        u32     hash_algorithm_id;
        u32     hash[HASH_SUM_LEN];     /* Reserve 512 bits for the hash */
        u32     partition_number;
        u32     enc_algorithm_id;
        u32     encrypt_start_offset;
        u32     encrypt_size;
};
#endif

/* Structure of the main header, version 1 (Armada 370/XP/375/38x/39x) */
struct a38x_main_hdr_v1 {
        u8  blockid;               /* 0x0       */
        u8  flags;                 /* 0x1       */
        u16 nandpagesize;          /* 0x2-0x3   */
        u32 blocksize;             /* 0x4-0x7   */
        u8  version;               /* 0x8       */
        u8  headersz_msb;          /* 0x9       */
        u16 headersz_lsb;          /* 0xA-0xB   */
        u32 srcaddr;               /* 0xC-0xF   */
        u32 destaddr;              /* 0x10-0x13 */
        u32 execaddr;              /* 0x14-0x17 */
        u8  options;               /* 0x18      */
        u8  nandblocksize;         /* 0x19      */
        u8  nandbadblklocation;    /* 0x1A      */
        u8  reserved4;             /* 0x1B      */
        u16 reserved5;             /* 0x1C-0x1D */
        u8  ext;                   /* 0x1E      */
        u8  checksum;              /* 0x1F      */
};

struct a38x_boot_mode {
        unsigned int id;
        const char *name;
};

/* The blockid header field values used to indicate boot device of image */
struct a38x_boot_mode a38x_boot_modes[] = {
        { 0x4D, "i2c"  },
        { 0x5A, "spi"  },
        { 0x69, "uart" },
        { 0x78, "sata" },
        { 0x8B, "nand" },
        { 0x9C, "pex"  },
        { 0xAE, "mmc"  },
        {},
};

struct bubt_dev {
        char name[8];
        size_t (*read)(const char *file_name);
        int (*write)(size_t image_size);
        int (*active)(void);
};

static ulong get_load_addr(void)
{
        const char *addr_str;
        unsigned long addr;

        addr_str = env_get("loadaddr");
        if (addr_str)
                addr = hextoul(addr_str, NULL);
        else
                addr = CONFIG_SYS_LOAD_ADDR;

        return addr;
}

/********************************************************************
 *     eMMC services
 ********************************************************************/
#if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(MMC_WRITE)
static int mmc_burn_image(size_t image_size)
{
        struct mmc      *mmc;
        lbaint_t        start_lba;
        lbaint_t        blk_count;
        ulong           blk_written;
        int             err;
        const u8        mmc_dev_num = CONFIG_SYS_MMC_ENV_DEV;
#ifdef CONFIG_BLK
        struct blk_desc *blk_desc;
#endif
        mmc = find_mmc_device(mmc_dev_num);
        if (!mmc) {
                printf("No SD/MMC/eMMC card found\n");
                return -ENOMEDIUM;
        }

        err = mmc_init(mmc);
        if (err) {
                printf("%s(%d) init failed\n", IS_SD(mmc) ? "SD" : "MMC",
                       mmc_dev_num);
                return err;
        }

        /* SD reserves LBA-0 for MBR and boots from LBA-1,
         * MMC/eMMC boots from LBA-0
         */
        start_lba = IS_SD(mmc) ? 1 : 0;
#ifdef CONFIG_BLK
        blk_count = image_size / mmc->write_bl_len;
        if (image_size % mmc->write_bl_len)
                blk_count += 1;

        blk_desc = mmc_get_blk_desc(mmc);
        if (!blk_desc) {
                printf("Error - failed to obtain block descriptor\n");
                return -ENODEV;
        }
        blk_written = blk_dwrite(blk_desc, start_lba, blk_count,
                                 (void *)get_load_addr());
#else
        blk_count = image_size / mmc->block_dev.blksz;
        if (image_size % mmc->block_dev.blksz)
                blk_count += 1;

        blk_written = mmc->block_dev.block_write(mmc_dev_num,
                                                 start_lba, blk_count,
                                                 (void *)get_load_addr());
#endif /* CONFIG_BLK */
        if (blk_written != blk_count) {
                printf("Error - written %#lx blocks\n", blk_written);
                return -ENOSPC;
        }
        printf("Done!\n");

        return 0;
}

static size_t mmc_read_file(const char *file_name)
{
        loff_t          act_read = 0;
        int             rc;
        struct mmc      *mmc;
        const u8        mmc_dev_num = CONFIG_SYS_MMC_ENV_DEV;

        mmc = find_mmc_device(mmc_dev_num);
        if (!mmc) {
                printf("No SD/MMC/eMMC card found\n");
                return 0;
        }

        if (mmc_init(mmc)) {
                printf("%s(%d) init failed\n", IS_SD(mmc) ? "SD" : "MMC",
                       mmc_dev_num);
                return 0;
        }

        /* Load from data partition (0) */
        if (fs_set_blk_dev("mmc", "0", FS_TYPE_ANY)) {
                printf("Error: MMC 0 not found\n");
                return 0;
        }

        /* Perfrom file read */
        rc = fs_read(file_name, get_load_addr(), 0, 0, &act_read);
        if (rc)
                return 0;

        return act_read;
}

static int is_mmc_active(void)
{
        return 1;
}
#else /* CONFIG_DM_MMC */
static int mmc_burn_image(size_t image_size)
{
        return -ENODEV;
}

static size_t mmc_read_file(const char *file_name)
{
        return 0;
}

static int is_mmc_active(void)
{
        return 0;
}
#endif /* CONFIG_DM_MMC */

/********************************************************************
 *     SPI services
 ********************************************************************/
#ifdef CONFIG_SPI_FLASH
static int spi_burn_image(size_t image_size)
{
        int ret;
        struct spi_flash *flash;
        u32 erase_bytes;

        /* Probe the SPI bus to get the flash device */
        flash = spi_flash_probe(CONFIG_ENV_SPI_BUS,
                                CONFIG_ENV_SPI_CS,
                                CONFIG_SF_DEFAULT_SPEED,
                                CONFIG_SF_DEFAULT_MODE);
        if (!flash) {
                printf("Failed to probe SPI Flash\n");
                return -ENOMEDIUM;
        }

        erase_bytes = image_size +
                (flash->erase_size - image_size % flash->erase_size);
        printf("Erasing %d bytes (%d blocks) at offset 0 ...",
               erase_bytes, erase_bytes / flash->erase_size);
        ret = spi_flash_erase(flash, 0, erase_bytes);
        if (ret)
                printf("Error!\n");
        else
                printf("Done!\n");

        printf("Writing %d bytes from 0x%lx to offset 0 ...",
               (int)image_size, get_load_addr());
        ret = spi_flash_write(flash, 0, image_size, (void *)get_load_addr());
        if (ret)
                printf("Error!\n");
        else
                printf("Done!\n");

        return ret;
}

static int is_spi_active(void)
{
        return 1;
}

#else /* CONFIG_SPI_FLASH */
static int spi_burn_image(size_t image_size)
{
        return -ENODEV;
}

static int is_spi_active(void)
{
        return 0;
}
#endif /* CONFIG_SPI_FLASH */

/********************************************************************
 *     NAND services
 ********************************************************************/
#ifdef CONFIG_CMD_NAND
static int nand_burn_image(size_t image_size)
{
        int ret;
        uint32_t block_size;
        struct mtd_info *mtd;

        mtd = get_nand_dev_by_index(nand_curr_device);
        if (!mtd) {
                puts("\nno devices available\n");
                return -ENOMEDIUM;
        }
        block_size = mtd->erasesize;

        /* Align U-Boot size to currently used blocksize */
        image_size = ((image_size + (block_size - 1)) & (~(block_size - 1)));

        /* Erase the U-Boot image space */
        printf("Erasing 0x%x - 0x%x:...", 0, (int)image_size);
        ret = nand_erase(mtd, 0, image_size);
        if (ret) {
                printf("Error!\n");
                goto error;
        }
        printf("Done!\n");

        /* Write the image to flash */
        printf("Writing %d bytes from 0x%lx to offset 0 ... ",
               (int)image_size, get_load_addr());
        ret = nand_write(mtd, 0, &image_size, (void *)get_load_addr());
        if (ret)
                printf("Error!\n");
        else
                printf("Done!\n");

error:
        return ret;
}

static int is_nand_active(void)
{
        return 1;
}

#else /* CONFIG_CMD_NAND */
static int nand_burn_image(size_t image_size)
{
        return -ENODEV;
}

static int is_nand_active(void)
{
        return 0;
}
#endif /* CONFIG_CMD_NAND */

/********************************************************************
 *     USB services
 ********************************************************************/
#if defined(CONFIG_USB_STORAGE) && defined(CONFIG_BLK)
static size_t usb_read_file(const char *file_name)
{
        loff_t act_read = 0;
        struct udevice *dev;
        int rc;

        usb_stop();

        if (usb_init() < 0) {
                printf("Error: usb_init failed\n");
                return 0;
        }

        /* Try to recognize storage devices immediately */
        blk_first_device(IF_TYPE_USB, &dev);
        if (!dev) {
                printf("Error: USB storage device not found\n");
                return 0;
        }

        /* Always load from usb 0 */
        if (fs_set_blk_dev("usb", "0", FS_TYPE_ANY)) {
                printf("Error: USB 0 not found\n");
                return 0;
        }

        /* Perfrom file read */
        rc = fs_read(file_name, get_load_addr(), 0, 0, &act_read);
        if (rc)
                return 0;

        return act_read;
}

static int is_usb_active(void)
{
        return 1;
}

#else /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */
static size_t usb_read_file(const char *file_name)
{
        return 0;
}

static int is_usb_active(void)
{
        return 0;
}
#endif /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */

/********************************************************************
 *     Network services
 ********************************************************************/
#ifdef CONFIG_CMD_NET
static size_t tftp_read_file(const char *file_name)
{
        /*
         * update global variable image_load_addr before tftp file from network
         */
        image_load_addr = get_load_addr();
        return net_loop(TFTPGET);
}

static int is_tftp_active(void)
{
        return 1;
}

#else
static size_t tftp_read_file(const char *file_name)
{
        return 0;
}

static int is_tftp_active(void)
{
        return 0;
}
#endif /* CONFIG_CMD_NET */

enum bubt_devices {
        BUBT_DEV_NET = 0,
        BUBT_DEV_USB,
        BUBT_DEV_MMC,
        BUBT_DEV_SPI,
        BUBT_DEV_NAND,

        BUBT_MAX_DEV
};

struct bubt_dev bubt_devs[BUBT_MAX_DEV] = {
        {"tftp", tftp_read_file, NULL, is_tftp_active},
        {"usb",  usb_read_file,  NULL, is_usb_active},
        {"mmc",  mmc_read_file,  mmc_burn_image, is_mmc_active},
        {"spi",  NULL, spi_burn_image,  is_spi_active},
        {"nand", NULL, nand_burn_image, is_nand_active},
};

static int bubt_write_file(struct bubt_dev *dst, size_t image_size)
{
        if (!dst->write) {
                printf("Error: Write not supported on device %s\n", dst->name);
                return -ENOTSUPP;
        }

        return dst->write(image_size);
}

#if defined(CONFIG_ARMADA_8K)
u32 do_checksum32(u32 *start, int32_t len)
{
        u32 sum = 0;
        u32 *startp = start;

        do {
                sum += *startp;
                startp++;
                len -= 4;
        } while (len > 0);

        return sum;
}

static int check_image_header(void)
{
        struct mvebu_image_header *hdr =
                        (struct mvebu_image_header *)get_load_addr();
        u32 header_len = hdr->prolog_size;
        u32 checksum;
        u32 checksum_ref = hdr->prolog_checksum;

        /*
         * For now compare checksum, and magic. Later we can
         * verify more stuff on the header like interface type, etc
         */
        if (hdr->magic != MAIN_HDR_MAGIC) {
                printf("ERROR: Bad MAGIC 0x%08x != 0x%08x\n",
                       hdr->magic, MAIN_HDR_MAGIC);
                return -ENOEXEC;
        }

        /* The checksum value is discarded from checksum calculation */
        hdr->prolog_checksum = 0;

        checksum = do_checksum32((u32 *)hdr, header_len);
        if (checksum != checksum_ref) {
                printf("Error: Bad Image checksum. 0x%x != 0x%x\n",
                       checksum, checksum_ref);
                return -ENOEXEC;
        }

        /* Restore the checksum before writing */
        hdr->prolog_checksum = checksum_ref;
        printf("Image checksum...OK!\n");

        return 0;
}
#elif defined(CONFIG_ARMADA_3700) /* Armada 3700 */
static int check_image_header(void)
{
        struct common_tim_data *hdr = (struct common_tim_data *)get_load_addr();
        int image_num;
        u8 hash_160_output[SHA1_SUM_LEN];
        u8 hash_256_output[SHA256_SUM_LEN];
        sha1_context hash1_text;
        sha256_context hash256_text;
        u8 *hash_output;
        u32 hash_algorithm_id;
        u32 image_size_to_hash;
        u32 flash_entry_addr;
        u32 *hash_value;
        u32 internal_hash[HASH_SUM_LEN];
        const u8 *buff;
        u32 num_of_image = hdr->num_images;
        u32 version = hdr->version;
        u32 trusted = hdr->trusted;

        /* bubt checksum validation only supports nontrusted images */
        if (trusted == 1) {
                printf("bypass image validation, ");
                printf("only untrusted image is supported now\n");
                return 0;
        }
        /* only supports image version 3.5 and 3.6 */
        if (version != IMAGE_VERSION_3_5_0 && version != IMAGE_VERSION_3_6_0) {
                printf("Error: Unsupported Image version = 0x%08x\n", version);
                return -ENOEXEC;
        }
        /* validate images hash value */
        for (image_num = 0; image_num < num_of_image; image_num++) {
                struct mvebu_image_info *info =
                                (struct mvebu_image_info *)(get_load_addr() +
                                sizeof(struct common_tim_data) +
                                image_num * sizeof(struct mvebu_image_info));
                hash_algorithm_id = info->hash_algorithm_id;
                image_size_to_hash = info->image_size_to_hash;
                flash_entry_addr = info->flash_entry_addr;
                hash_value = info->hash;
                buff = (const u8 *)(get_load_addr() + flash_entry_addr);

                if (image_num == 0) {
                        /*
                         * The first image includes hash values in its content.
                         * For hash calculation, we need to save the original
                         * hash values to a local variable that will be
                         * copied back for comparsion and set all zeros to
                         * the orignal hash values for calculating new value.
                         * First image original format :
                         * x...x (datum1) x...x(orig. hash values) x...x(datum2)
                         * Replaced first image format :
                         * x...x (datum1) 0...0(hash values) x...x(datum2)
                         */
                        memcpy(internal_hash, hash_value,
                               sizeof(internal_hash));
                        memset(hash_value, 0, sizeof(internal_hash));
                }
                if (image_size_to_hash == 0) {
                        printf("Warning: Image_%d hash checksum is disabled, ",
                               image_num);
                        printf("skip the image validation.\n");
                        continue;
                }
                switch (hash_algorithm_id) {
                case SHA1_SUM_LEN:
                        sha1_starts(&hash1_text);
                        sha1_update(&hash1_text, buff, image_size_to_hash);
                        sha1_finish(&hash1_text, hash_160_output);
                        hash_output = hash_160_output;
                        break;
                case SHA256_SUM_LEN:
                        sha256_starts(&hash256_text);
                        sha256_update(&hash256_text, buff, image_size_to_hash);
                        sha256_finish(&hash256_text, hash_256_output);
                        hash_output = hash_256_output;
                        break;
                default:
                        printf("Error: Unsupported hash_algorithm_id = %d\n",
                               hash_algorithm_id);
                        return -ENOEXEC;
                }
                if (image_num == 0)
                        memcpy(hash_value, internal_hash,
                               sizeof(internal_hash));
                if (memcmp(hash_value, hash_output, hash_algorithm_id) != 0) {
                        printf("Error: Image_%d checksum is not correct\n",
                               image_num);
                        return -ENOEXEC;
                }
        }
        printf("Image checksum...OK!\n");

        return 0;
}
#elif defined(CONFIG_ARMADA_38X)
static size_t a38x_header_size(const struct a38x_main_hdr_v1 *h)
{
        if (h->version == 1)
                return (h->headersz_msb << 16) | le16_to_cpu(h->headersz_lsb);

        printf("Error: Invalid A38x image (header version 0x%x unknown)!\n",
               h->version);
        return 0;
}

static uint8_t image_checksum8(const void *start, size_t len)
{
        u8 csum = 0;
        const u8 *p = start;

        while (len) {
                csum += *p;
                ++p;
                --len;
        }

        return csum;
}

static int check_image_header(void)
{
        u8 checksum;
        const struct a38x_main_hdr_v1 *hdr =
                (struct a38x_main_hdr_v1 *)get_load_addr();
        const size_t image_size = a38x_header_size(hdr);

        if (!image_size)
                return -ENOEXEC;

        checksum = image_checksum8(hdr, image_size);
        checksum -= hdr->checksum;
        if (checksum != hdr->checksum) {
                printf("Error: Bad A38x image checksum. 0x%x != 0x%x\n",
                       checksum, hdr->checksum);
                return -ENOEXEC;
        }

        printf("Image checksum...OK!\n");
        return 0;
}
#else /* Not ARMADA? */
static int check_image_header(void)
{
        printf("bubt cmd does not support this SoC device or family!\n");
        return -ENOEXEC;
}
#endif

static int bubt_check_boot_mode(const struct bubt_dev *dst)
{
        if (IS_ENABLED(CONFIG_ARMADA_38X)) {
                int mode;
                const struct a38x_main_hdr_v1 *hdr =
                        (struct a38x_main_hdr_v1 *)get_load_addr();

                for (mode = 0; mode < ARRAY_SIZE(a38x_boot_modes); mode++) {
                        if (strcmp(a38x_boot_modes[mode].name, dst->name) == 0)
                                break;
                }

                if (a38x_boot_modes[mode].id == hdr->blockid)
                        return 0;

                for (int i = 0; i < ARRAY_SIZE(a38x_boot_modes); i++) {
                        if (a38x_boot_modes[i].id == hdr->blockid) {
                                printf("Error: A38x image meant to be booted from "
                                       "\"%s\", not \"%s\"!\n",
                                       a38x_boot_modes[i].name, dst->name);
                                return -ENOEXEC;
                        }
                }

                printf("Error: unknown boot device in A38x image header: "
                       "0x%x\n", hdr->blockid);
                return -ENOEXEC;
        } else {
                return 0;
        }
}

static int bubt_verify(const struct bubt_dev *dst)
{
        int err;

        /* Check a correct image header exists */
        err = check_image_header();
        if (err) {
                printf("Error: Image header verification failed\n");
                return err;
        }

        err = bubt_check_boot_mode(dst);
        if (err) {
                printf("Error: Image boot mode verification failed\n");
                return err;
        }

        return 0;
}

static int bubt_read_file(struct bubt_dev *src)
{
        size_t image_size;

        if (!src->read) {
                printf("Error: Read not supported on device \"%s\"\n",
                       src->name);
                return 0;
        }

        image_size = src->read(net_boot_file_name);
        if (image_size <= 0) {
                printf("Error: Failed to read file %s from %s\n",
                       net_boot_file_name, src->name);
                return 0;
        }

        return image_size;
}

static int bubt_is_dev_active(struct bubt_dev *dev)
{
        if (!dev->active) {
                printf("Device \"%s\" not supported by U-Boot image\n",
                       dev->name);
                return 0;
        }

        if (!dev->active()) {
                printf("Device \"%s\" is inactive\n", dev->name);
                return 0;
        }

        return 1;
}

struct bubt_dev *find_bubt_dev(char *dev_name)
{
        int dev;

        for (dev = 0; dev < BUBT_MAX_DEV; dev++) {
                if (strcmp(bubt_devs[dev].name, dev_name) == 0)
                        return &bubt_devs[dev];
        }

        return 0;
}

#define DEFAULT_BUBT_SRC "tftp"

#ifndef DEFAULT_BUBT_DST
#ifdef CONFIG_MVEBU_SPI_BOOT
#define DEFAULT_BUBT_DST "spi"
#elif defined(CONFIG_MVEBU_NAND_BOOT)
#define DEFAULT_BUBT_DST "nand"
#elif defined(CONFIG_MVEBU_MMC_BOOT)
#define DEFAULT_BUBT_DST "mmc"
#else
#define DEFAULT_BUBT_DST "error"
#endif
#endif /* DEFAULT_BUBT_DST */

int do_bubt_cmd(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        struct bubt_dev *src, *dst;
        size_t image_size;
        char src_dev_name[8];
        char dst_dev_name[8];
        char *name;
        int  err;

        if (argc < 2)
                copy_filename(net_boot_file_name,
                              CONFIG_MVEBU_UBOOT_DFLT_NAME,
                              sizeof(net_boot_file_name));
        else
                copy_filename(net_boot_file_name, argv[1],
                              sizeof(net_boot_file_name));

        if (argc >= 3) {
                strncpy(dst_dev_name, argv[2], 8);
        } else {
                name = DEFAULT_BUBT_DST;
                strncpy(dst_dev_name, name, 8);
        }

        if (argc >= 4)
                strncpy(src_dev_name, argv[3], 8);
        else
                strncpy(src_dev_name, DEFAULT_BUBT_SRC, 8);

        /* Figure out the destination device */
        dst = find_bubt_dev(dst_dev_name);
        if (!dst) {
                printf("Error: Unknown destination \"%s\"\n", dst_dev_name);
                return -EINVAL;
        }

        if (!bubt_is_dev_active(dst))
                return -ENODEV;

        /* Figure out the source device */
        src = find_bubt_dev(src_dev_name);
        if (!src) {
                printf("Error: Unknown source \"%s\"\n", src_dev_name);
                return 1;
        }

        if (!bubt_is_dev_active(src))
                return -ENODEV;

        printf("Burning U-Boot image \"%s\" from \"%s\" to \"%s\"\n",
               net_boot_file_name, src->name, dst->name);

        image_size = bubt_read_file(src);
        if (!image_size)
                return -EIO;

        err = bubt_verify(dst);
        if (err)
                return err;

        err = bubt_write_file(dst, image_size);
        if (err)
                return err;

        return 0;
}

U_BOOT_CMD(
        bubt, 4, 0, do_bubt_cmd,
        "Burn a u-boot image to flash",
        "[file-name] [destination [source]]\n"
        "\t-file-name     The image file name to burn. Default = " CONFIG_MVEBU_UBOOT_DFLT_NAME "\n"
        "\t-destination   Flash to burn to [spi, nand, mmc]. Default = " DEFAULT_BUBT_DST "\n"
        "\t-source        The source to load image from [tftp, usb, mmc]. Default = " DEFAULT_BUBT_SRC "\n"
        "Examples:\n"
        "\tbubt - Burn flash-image.bin from tftp to active boot device\n"
        "\tbubt flash-image-new.bin nand - Burn flash-image-new.bin from tftp to NAND flash\n"
        "\tbubt backup-flash-image.bin mmc usb - Burn backup-flash-image.bin from usb to MMC\n"

);