#include <stdio.h>
  #include <unistd.h>
  #include <getopt.h>
  #include <stdlib.h>
  #include <stdint.h>
  #include <string.h>
  #include <errno.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <endian.h>
  
  #define VALIDATION_WORD 0x31305341
  
  #define MAX_IMAGE_SIZE (60 * 1024 - 4)
  
  static int add_barebox_header;
  
  struct socfpga_header {
  	uint8_t validation_word[4];
  	uint8_t version;
  	uint8_t flags;
  	uint8_t program_length[2];
  	uint8_t spare[2];
  	uint8_t checksum[2];
  };
  
  static uint32_t bb_header[] = {
  	0xea00007e,	/* b 0x200  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0xeafffffe,	/* 1: b 1b  */
  	0x65726162,	/* 'bare'   */
  	0x00786f62,	/* 'box\0'  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* padding  */
  	0x00000000,	/* socfpga header */
  	0x00000000,	/* socfpga header */
  	0x00000000,	/* socfpga header */
  	0xea00006b,	/* entry. b 0x200  */
  };
  
  static int read_full(int fd, void *buf, size_t size)
  {
  	size_t insize = size;
  	int now;
  	int total = 0;
  
  	while (size) {
  		now = read(fd, buf, size);
  		if (now == 0)
  			return total;
  		if (now < 0)
  			return now;
  		total += now;
  		size -= now;
  		buf += now;
  	}
  
  	return insize;
  }
  
  static int write_full(int fd, void *buf, size_t size)
  {
  	size_t insize = size;
  	int now;
  
  	while (size) {
  		now = write(fd, buf, size);
  		if (now <= 0)
  			return now;
  		size -= now;
  		buf += now;
  	}
  
  	return insize;
  }
  
  static uint32_t crc_table[256] = {
  	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
  	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
  	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
  	0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
  	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
  	0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
  	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
  	0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
  	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
  	0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
  	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
  	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
  	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
  	0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
  	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
  	0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
  	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
  	0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
  	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
  	0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
  	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
  	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
  	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
  	0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
  	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
  	0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
  	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
  	0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
  	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
  	0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
  	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
  	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
  	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
  	0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
  	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
  	0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
  	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
  	0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
  	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
  	0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
  	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
  	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
  	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
  };
  
  uint32_t crc32(uint32_t crc, void *_buf, int length)
  {
  	uint8_t *buf = _buf;
  
  	while (length--)
  		crc = crc << 8 ^ crc_table[(crc >> 24 ^ *(buf++)) & 0xff];
  
  	return crc;
  }
  
  static int add_socfpga_header(void *buf, int size)
  {
  	struct socfpga_header *header = buf + 0x40;
  	uint8_t *buf_header = buf + 0x40;
  	uint32_t *crc;
  	unsigned checksum;
  	int length = size >> 2;
  	int i;
  
  	if (size & 0x3) {
  		fprintf(stderr, "%s: size must be multiple of 4
  ", __func__);
  		return -EINVAL;
  	}
  
  	header->validation_word[0] = VALIDATION_WORD & 0xff;
  	header->validation_word[1] = (VALIDATION_WORD >> 8) & 0xff;
  	header->validation_word[2] = (VALIDATION_WORD >> 16) & 0xff;
  	header->validation_word[3] = (VALIDATION_WORD >> 24) & 0xff;
  	header->version = 0;
  	header->flags = 0;
  	header->program_length[0] = length & 0xff;
  	header->program_length[1] = (length >> 8) & 0xff;
  	header->spare[0] = 0;
  	header->spare[1] = 0;
  
  	checksum = 0;
  	for (i = 0; i < sizeof(*header) - 2; i++)
  		checksum += buf_header[i];
  
  	header->checksum[0] = checksum & 0xff;;
  	header->checksum[1] = (checksum >> 8) & 0xff;;
  
  	crc = buf + size - sizeof(uint32_t);
  
  	*crc = crc32(0xffffffff, buf, size - sizeof(uint32_t));
  	*crc ^= 0xffffffff;
  
  	return 0;
  }
  
  static void usage(const char *prgname)
  {
  	fprintf(stderr, "usage: %s [OPTIONS] <infile>
  ", prgname);
  }
  
  int main(int argc, char *argv[])
  {
  	int opt, ret;
  	const char *outfile = NULL, *infile;
  	struct stat s;
  	void *buf;
  	int fd;
  	int min_image_size = 80;
  	int max_image_size = MAX_IMAGE_SIZE;
  	int addsize = 0, pad;
  
  	while ((opt = getopt(argc, argv, "o:hb")) != -1) {
  		switch (opt) {
  		case 'b':
  			add_barebox_header = 1;
  			min_image_size = 0;
  			max_image_size = MAX_IMAGE_SIZE - 512;
  			addsize = 512;
  			break;
  		case 'h':
  			usage(argv[0]);
  			exit(0);
  		case 'o':
  			outfile = optarg;
  			break;
  		default:
  			exit(1);
  		}
  	}
  
  	if (optind == argc) {
  		usage(argv[0]);
  		exit(1);
  	}
  
  	infile = argv[optind];
  
  	ret = stat(infile, &s);
  	if (ret) {
  		perror("stat");
  		exit(1);
  	}
  
  	if (s.st_size < min_image_size) {
  		fprintf(stderr, "input image too small. Minimum is 80 bytes
  ");
  		exit(1);
  	}
  
  	if (s.st_size > max_image_size) {
  		fprintf(stderr, "input image too big. Maximum is %d bytes, got %ld bytes
  ",
  				max_image_size, s.st_size);
  		exit(1);
  	}
  
  	fd = open(infile, O_RDONLY);
  	if (fd < 0) {
  		perror("open infile");
  		exit(1);
  	}
  
  	pad = s.st_size & 0x3;
  	if (pad)
  		pad = 4 - pad;
  
  	buf = calloc(s.st_size + 4 + addsize + pad, 1);
  	if (!buf) {
  		perror("malloc");
  		exit(1);
  	}
  
  	ret = read_full(fd, buf + addsize, s.st_size);
  	if (ret < 0) {
  		perror("read infile");
  		exit(1);
  	}
  
  	close(fd);
  
  	if (add_barebox_header) {
  		memcpy(buf, bb_header, sizeof(bb_header));
  	}
  
  	ret = add_socfpga_header(buf, s.st_size + 4 + addsize + pad);
  	if (ret)
  		exit(1);
  
  	fd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
  	if (fd < 0) {
  		perror("open outfile");
  		exit(1);
  	}
  
  	ret = write_full(fd, buf, s.st_size + 4 + addsize + pad);
  	if (ret < 0) {
  		perror("write outfile");
  		exit(1);
  	}
  
  	exit(0);
  }