ihex2fw.c

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/*
 * Parser/loader for IHEX formatted data.
 *
 * Copyright © 2008 David Woodhouse <[email protected]>
 * Copyright © 2005 Jan Harkes <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <stdint.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#define _GNU_SOURCE
#include <getopt.h>


struct ihex_binrec {
    struct ihex_binrec *next; /* not part of the real data structure */
        uint32_t addr;
        uint16_t len;
        uint8_t data[];
};

static uint8_t nybble(const uint8_t n)
{
       if      (n >= '0' && n <= '9') return n - '0';
       else if (n >= 'A' && n <= 'F') return n - ('A' - 10);
       else if (n >= 'a' && n <= 'f') return n - ('a' - 10);
       return 0;
}

static uint8_t hex(const uint8_t *data, uint8_t *crc)
{
       uint8_t val = (nybble(data[0]) << 4) | nybble(data[1]);
       *crc += val;
       return val;
}

static int process_ihex(uint8_t *data, ssize_t size);
static void file_record(struct ihex_binrec *record);
static int output_records(int outfd);

static int sort_records = 0;
static int wide_records = 0;
static int include_jump = 0;

static int usage(void)
{
    fprintf(stderr, "ihex2fw: Convert ihex files into binary "
        "representation for use by Linux kernel\n");
    fprintf(stderr, "usage: ihex2fw [<options>] <src.HEX> <dst.fw>\n");
    fprintf(stderr, "       -w: wide records (16-bit length)\n");
    fprintf(stderr, "       -s: sort records by address\n");
    fprintf(stderr, "       -j: include records for CS:IP/EIP address\n");
    return 1;
}

int main(int argc, char **argv)
{
    int infd, outfd;
    struct stat st;
    uint8_t *data;
    int opt;

    while ((opt = getopt(argc, argv, "wsj")) != -1) {
        switch (opt) {
        case 'w':
            wide_records = 1;
            break;
        case 's':
            sort_records = 1;
            break;
        case 'j':
            include_jump = 1;
            break;
            return usage();
        }
    }

    if (optind + 2 != argc)
        return usage();

    if (!strcmp(argv[optind], "-"))
        infd = 0;
    else
        infd = open(argv[optind], O_RDONLY);
    if (infd == -1) {
        fprintf(stderr, "Failed to open source file: %s",
            strerror(errno));
        return usage();
    }
    if (fstat(infd, &st)) {
        perror("stat");
        return 1;
    }
    data = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, infd, 0);
    if (data == MAP_FAILED) {
        perror("mmap");
        return 1;
    }

    if (!strcmp(argv[optind+1], "-"))
        outfd = 1;
    else
        outfd = open(argv[optind+1], O_TRUNC|O_CREAT|O_WRONLY, 0644);
    if (outfd == -1) {
        fprintf(stderr, "Failed to open destination file: %s",
            strerror(errno));
        return usage();
    }
    if (process_ihex(data, st.st_size))
        return 1;

    return output_records(outfd);
}

static int process_ihex(uint8_t *data, ssize_t size)
{
    struct ihex_binrec *record;
    uint32_t offset = 0;
    uint32_t data32;
    uint8_t type, crc = 0, crcbyte = 0;
    int i, j;
    int line = 1;
    int len;

    i = 0;
next_record:
    /* search for the start of record character */
    while (i < size) {
        if (data[i] == '\n') line++;
        if (data[i++] == ':') break;
    }

    /* Minimum record length would be about 10 characters */
    if (i + 10 > size) {
        fprintf(stderr, "Can't find valid record at line %d\n", line);
        return -EINVAL;
    }

    len = hex(data + i, &crc); i += 2;
    if (wide_records) {
        len <<= 8;
        len += hex(data + i, &crc); i += 2;
    }
    record = malloc((sizeof (*record) + len + 3) & ~3);
    if (!record) {
        fprintf(stderr, "out of memory for records\n");
        return -ENOMEM;
    }
    memset(record, 0, (sizeof(*record) + len + 3) & ~3);
    record->len = len;

    /* now check if we have enough data to read everything */
    if (i + 8 + (record->len * 2) > size) {
        fprintf(stderr, "Not enough data to read complete record at line %d\n",
            line);
        return -EINVAL;
    }

    record->addr  = hex(data + i, &crc) << 8; i += 2;
    record->addr |= hex(data + i, &crc); i += 2;
    type = hex(data + i, &crc); i += 2;

    for (j = 0; j < record->len; j++, i += 2)
        record->data[j] = hex(data + i, &crc);

    /* check CRC */
    crcbyte = hex(data + i, &crc); i += 2;
    if (crc != 0) {
        fprintf(stderr, "CRC failure at line %d: got 0x%X, expected 0x%X\n",
            line, crcbyte, (unsigned char)(crcbyte-crc));
        return -EINVAL;
    }

    /* Done reading the record */
    switch (type) {
    case 0:
        /* old style EOF record? */
        if (!record->len)
            break;

        record->addr += offset;
        file_record(record);
        goto next_record;

    case 1: /* End-Of-File Record */
        if (record->addr || record->len) {
            fprintf(stderr, "Bad EOF record (type 01) format at line %d",
                line);
            return -EINVAL;
        }
        break;

    case 2: /* Extended Segment Address Record (HEX86) */
    case 4: /* Extended Linear Address Record (HEX386) */
        if (record->addr || record->len != 2) {
            fprintf(stderr, "Bad HEX86/HEX386 record (type %02X) at line %d\n",
                type, line);
            return -EINVAL;
        }

        /* We shouldn't really be using the offset for HEX86 because
         * the wraparound case is specified quite differently. */
        offset = record->data[0] << 8 | record->data[1];
        offset <<= (type == 2 ? 4 : 16);
        goto next_record;

    case 3: /* Start Segment Address Record */
    case 5: /* Start Linear Address Record */
        if (record->addr || record->len != 4) {
            fprintf(stderr, "Bad Start Address record (type %02X) at line %d\n",
                type, line);
            return -EINVAL;
        }

        memcpy(&data32, &record->data[0], sizeof(data32));
        data32 = htonl(data32);
        memcpy(&record->data[0], &data32, sizeof(data32));

        /* These records contain the CS/IP or EIP where execution
         * starts. If requested output this as a record. */
        if (include_jump)
            file_record(record);
        goto next_record;

    default:
        fprintf(stderr, "Unknown record (type %02X)\n", type);
        return -EINVAL;
    }

    return 0;
}

static struct ihex_binrec *records;

static void file_record(struct ihex_binrec *record)
{
    struct ihex_binrec **p = &records;

    while ((*p) && (!sort_records || (*p)->addr < record->addr))
        p = &((*p)->next);

    record->next = *p;
    *p = record;
}

static int output_records(int outfd)
{
    unsigned char zeroes[6] = {0, 0, 0, 0, 0, 0};
    struct ihex_binrec *p = records;

    while (p) {
        uint16_t writelen = (p->len + 9) & ~3;

        p->addr = htonl(p->addr);
        p->len = htons(p->len);
        if (write(outfd, &p->addr, writelen) != writelen)
            return 1;
        p = p->next;
    }
    /* EOF record is zero length, since we don't bother to represent
       the type field in the binary version */
    if (write(outfd, zeroes, 6) != 6)
        return 1;
    return 0;
}