// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007-2011
 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
 * Tom Cubie <tangliang@allwinnertech.com>
 *
 * a simple tool to generate bootable image for sunxi platform.
 */
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "imagetool.h"
#include "../arch/arm/include/asm/arch-sunxi/spl.h"

#define STAMP_VALUE                     0x5F0A6C39

/* check sum functon from sun4i boot code */
int gen_check_sum(struct boot_file_head *head_p)
{
        uint32_t length;
        uint32_t *buf;
        uint32_t loop;
        uint32_t i;
        uint32_t sum;

        length = le32_to_cpu(head_p->length);
        if ((length & 0x3) != 0)        /* must 4-byte-aligned */
                return -1;
        buf = (uint32_t *)head_p;
        head_p->check_sum = cpu_to_le32(STAMP_VALUE);   /* fill stamp */
        loop = length >> 2;

        /* calculate the sum */
        for (i = 0, sum = 0; i < loop; i++)
                sum += le32_to_cpu(buf[i]);

        /* write back check sum */
        head_p->check_sum = cpu_to_le32(sum);

        return 0;
}

#define SUNXI_SRAM_SIZE 0x8000  /* SoC with smaller size are limited before */
#define SRAM_LOAD_MAX_SIZE (SUNXI_SRAM_SIZE - sizeof(struct boot_file_head))

/*
 * BROM (at least on A10 and A20) requires NAND-images to be explicitly aligned
 * to a multiple of 8K, and rejects the image otherwise. MMC-images are fine
 * with 512B blocks. To cater for both, align to the largest of the two.
 */
#define BLOCK_SIZE 0x2000

struct boot_img {
        struct boot_file_head header;
        char code[SRAM_LOAD_MAX_SIZE];
        char pad[BLOCK_SIZE];
};

int main(int argc, char *argv[])
{
        int fd_in, fd_out;
        struct boot_img img;
        unsigned file_size;
        int count;
        char *tool_name = argv[0];
        char *default_dt = NULL;

        /* a sanity check */
        if ((sizeof(img.header) % 32) != 0) {
                fprintf(stderr, "ERROR: the SPL header must be a multiple ");
                fprintf(stderr, "of 32 bytes.\n");
                return EXIT_FAILURE;
        }

        /* process optional command line switches */
        while (argc >= 2 && argv[1][0] == '-') {
                if (strcmp(argv[1], "--default-dt") == 0) {
                        if (argc >= 3) {
                                default_dt = argv[2];
                                argv += 2;
                                argc -= 2;
                                continue;
                        }
                        fprintf(stderr, "ERROR: no --default-dt arg\n");
                        return EXIT_FAILURE;
                } else {
                        fprintf(stderr, "ERROR: bad option '%s'\n", argv[1]);
                        return EXIT_FAILURE;
                }
        }

        if (argc < 3) {
                printf("This program converts an input binary file to a sunxi bootable image.\n");
                printf("\nUsage: %s [options] input_file output_file\n",
                       tool_name);
                printf("Where [options] may be:\n");
                printf("  --default-dt arg         - 'arg' is the default device tree name\n");
                printf("                             (CONFIG_DEFAULT_DEVICE_TREE).\n");
                return EXIT_FAILURE;
        }

        fd_in = open(argv[1], O_RDONLY);
        if (fd_in < 0) {
                perror("Open input file");
                return EXIT_FAILURE;
        }

        memset(&img, 0, sizeof(img));

        /* get input file size */
        file_size = lseek(fd_in, 0, SEEK_END);

        if (file_size > SRAM_LOAD_MAX_SIZE) {
                fprintf(stderr, "ERROR: File too large!\n");
                return EXIT_FAILURE;
        }

        fd_out = open(argv[2], O_WRONLY | O_CREAT, 0666);
        if (fd_out < 0) {
                perror("Open output file");
                return EXIT_FAILURE;
        }

        /* read file to buffer to calculate checksum */
        lseek(fd_in, 0, SEEK_SET);
        count = read(fd_in, img.code, file_size);
        if (count != file_size) {
                perror("Reading input image");
                return EXIT_FAILURE;
        }

        /* fill the header */
        img.header.b_instruction =      /* b instruction */
                0xEA000000 |    /* jump to the first instr after the header */
                ((sizeof(struct boot_file_head) / sizeof(int) - 2)
                 & 0x00FFFFFF);
        memcpy(img.header.magic, BOOT0_MAGIC, 8);       /* no '0' termination */
        img.header.length =
                ALIGN(file_size + sizeof(struct boot_file_head), BLOCK_SIZE);
        img.header.b_instruction = cpu_to_le32(img.header.b_instruction);
        img.header.length = cpu_to_le32(img.header.length);

        memcpy(img.header.spl_signature, SPL_SIGNATURE, 3); /* "sunxi" marker */
        img.header.spl_signature[3] = SPL_HEADER_VERSION;

        if (default_dt) {
                if (strlen(default_dt) + 1 <= sizeof(img.header.string_pool)) {
                        strcpy((char *)img.header.string_pool, default_dt);
                        img.header.dt_name_offset =
                                cpu_to_le32(offsetof(struct boot_file_head,
                                                     string_pool));
                } else {
                        printf("WARNING: The SPL header is too small\n");
                        printf("         and has no space to store the dt name.\n");
                }
        }

        gen_check_sum(&img.header);

        count = write(fd_out, &img, le32_to_cpu(img.header.length));
        if (count != le32_to_cpu(img.header.length)) {
                perror("Writing output");
                return EXIT_FAILURE;
        }

        close(fd_in);
        close(fd_out);

        return EXIT_SUCCESS;
}