/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2008 Axel Gembe <ago@bastart.eu.org>
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>
#include <netinet/in.h>

#define IMAGETAG_MAGIC1			"OpenWRT BCM963xx"
#define IMAGETAG_MAGIC2			"V1"
#define IMAGETAG_VER			"6"
#define IMAGETAG_DEFAULT_LOADADDR	0x80010000
#define IMAGETAG_CRC_START		0xFFFFFFFF
#define FLASH_CFE_SIZE			0x10000			/* TODO: Make this a command line option */
#define FLASH_START			0xBFC00000		/* TODO: Make this a command line option */
#define FLASH_BS			(64 * 1024)		/* TODO: Make this a command line option */

/* Kernel header */
struct kernelhdr {
	uint32_t		loadaddr;	/* Kernel load address */
	uint32_t		entry;		/* Kernel entry point address */
	uint32_t		lzmalen;	/* Compressed length of the LZMA data that follows */
};

/* Image component */
struct imagecomp {
	uint8_t			address[12];	/* Address of this component as ASCII */
	uint8_t			len[10];	/* Length of this component as ASCII */
};

/* Image tag */
struct imagetag {
	uint8_t			tagver[4];	/*   0 -   3: Version of the tag as ASCII (2) */
	uint8_t			sig1[20];	/*   4 -  23: BCM_MAGIC_1 */
	uint8_t			sig2[14];	/*  24 -  37: BCM_MAGIC_2 */
	uint8_t			chipid[6];	/*  38 -  43: Chip id as ASCII (6345) */
	uint8_t			boardid[16];	/*  44 -  59: Board id as ASCII (96345GW2, etc...) */
	uint8_t			bigendian[2];	/*  60 -  61: "1" for big endian, "0" for little endian */
	uint8_t			imagelen[10];	/*  62 -  71: The length of all data that follows */
	struct imagecomp	cfe;		/*  72 -  93: The offset and length of CFE */
	struct imagecomp	rootfs;		/*  94 - 115: The offset and length of the root file system */
	struct imagecomp	kernel;		/* 116 - 137: The offset and length of the kernel */
	uint8_t			dualimage[2];	/* 138 - 139: use "0" here */
	uint8_t			inactive[2];	/* 140 - 141: use "0" here */
	uint8_t			reserved1[74];	/* 142 - 215: reserved */
	uint32_t		imagecrc;	/* 216 - 219: crc of the images (net byte order) */
	uint8_t			reserved2[16];	/* 220 - 235: reserved */
	uint32_t		headercrc;	/* 236 - 239: crc starting from sig1 until headercrc (net byte order) */
	uint8_t			reserved3[16];	/* 240 - 255: reserved */
};

static uint32_t crc32tab[256] = {
	0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
	0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
	0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
	0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
	0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
	0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
	0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
	0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
	0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
	0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
	0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
	0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
	0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
	0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
	0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
	0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
	0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
	0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
	0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
	0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
	0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
	0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
	0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
	0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
	0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
	0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
	0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
	0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
	0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
	0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
	0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
	0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
};

uint32_t crc32(uint32_t crc, uint8_t *data, size_t len)
{
	while (len--)
		crc = (crc >> 8) ^ crc32tab[(crc ^ *data++) & 0xFF];

	return crc;
}

size_t getlen(FILE *fp)
{
	size_t retval, curpos;

	if (!fp)
		return 0;

	curpos = ftell(fp);
	fseek(fp, 0, SEEK_END);
	retval = ftell(fp);
	fseek(fp, curpos, SEEK_SET);

	return retval;
}

int tagfile(const char *kernel, const char *rootfs, const char *bin,
	    const char *boardid, const char *chipid, const uint32_t loadaddr,
	    const uint32_t entry)
{
	struct imagetag tag;
	struct kernelhdr khdr;
	FILE *kernelfile = NULL, *rootfsfile = NULL, *binfile;
	size_t kerneloff, kernellen, rootfsoff, rootfslen, read;
	uint8_t readbuf[1024];
	uint32_t crc;

	memset(&tag, 0, sizeof(struct imagetag));

	if (strlen(boardid) >= sizeof(tag.boardid)) {
		fprintf(stderr, "Board id is too long!\n");
		return 1;
	}

	if (strlen(chipid) >= sizeof(tag.chipid)) {
		fprintf(stderr, "Chip id is too long!\n");
		return 1;
	}

	if (kernel && !(kernelfile = fopen(kernel, "rb"))) {
		fprintf(stderr, "Unable to open kernel \"%s\"\n", kernel);
		return 1;
	}

	if (rootfs && !(rootfsfile = fopen(rootfs, "rb"))) {
		fprintf(stderr, "Unable to open rootfs \"%s\"\n", rootfs);
		return 1;
	}

	if (!bin || !(binfile = fopen(bin, "wb"))) {
		fprintf(stderr, "Unable to open output file \"%s\"\n", bin);
		return 1;
	}

	/* Build the kernel address and length (doesn't need to be aligned, read only) */
	kerneloff = FLASH_START + FLASH_CFE_SIZE + sizeof(tag);
	kernellen = getlen(kernelfile);

	/* Build the kernel header */
	khdr.loadaddr	= htonl(loadaddr);
	khdr.entry	= htonl(entry);
	khdr.lzmalen	= htonl(kernellen);

	/* Increase the kernel size by the header size */
	kernellen += sizeof(khdr);

	/* Build the rootfs address and length (start and end do need to be aligned on flash erase block boundaries */
	rootfsoff = kerneloff + kernellen;
	rootfsoff = (rootfsoff % FLASH_BS) > 0 ? (((rootfsoff / FLASH_BS) + 1) * FLASH_BS) : rootfsoff;
	rootfslen = getlen(rootfsfile);
	rootfslen = (rootfslen % FLASH_BS) > 0 ? (((rootfslen / FLASH_BS) + 1) * FLASH_BS) : rootfslen;

	/* Seek to the start of the kernel */
	fseek(binfile, kerneloff - FLASH_START - FLASH_CFE_SIZE, SEEK_SET);

	/* Write the kernel header */
	crc = crc32(IMAGETAG_CRC_START, (uint8_t*)&khdr, sizeof(khdr));
	fwrite(&khdr, sizeof(khdr), 1, binfile);

	/* Write the kernel */
	while (kernelfile && !feof(kernelfile) && !ferror(kernelfile)) {
		read = fread(readbuf, sizeof(uint8_t), sizeof(readbuf), kernelfile);
		crc = crc32(crc, readbuf, read);
		fwrite(readbuf, sizeof(uint8_t), read, binfile);
	}

	/* Write the RootFS */
	fseek(binfile, rootfsoff - FLASH_START - FLASH_CFE_SIZE, SEEK_SET);
	while (rootfsfile && !feof(rootfsfile) && !ferror(rootfsfile)) {
		read = fread(readbuf, sizeof(uint8_t), sizeof(readbuf), rootfsfile);
		/*
		 * TODO: Is this necessary ?
		 * crc = crc32(crc, readbuf, read);
		 */
		fwrite(readbuf, sizeof(uint8_t), read, binfile);
	}

	/* Close the files */
	fclose(kernelfile);
	fclose(rootfsfile);

	/* Build the tag */
	strcpy(tag.tagver, IMAGETAG_VER);
	strncpy(tag.sig1, IMAGETAG_MAGIC1, sizeof(tag.sig1) - 1);
	strncpy(tag.sig2, IMAGETAG_MAGIC2, sizeof(tag.sig1) - 1);
	strcpy(tag.chipid, chipid);
	strcpy(tag.boardid, boardid);
	strcpy(tag.bigendian, "1");
	sprintf(tag.imagelen, "%lu", kernellen + rootfslen);

	/* We don't include CFE */
	strcpy(tag.cfe.address, "0");
	strcpy(tag.cfe.len, "0");

	if (kernelfile) {
		sprintf(tag.kernel.address, "%lu", kerneloff);
		sprintf(tag.kernel.len, "%lu", kernellen);
	}

	if (rootfsfile) {
		sprintf(tag.rootfs.address, "%lu", rootfsoff);
		sprintf(tag.rootfs.len, "%lu", rootfslen);
	}

	tag.imagecrc = htonl(crc);
	tag.headercrc = htonl(crc32(IMAGETAG_CRC_START, (uint8_t*)&tag, sizeof(tag) - 20));

	fseek(binfile, 0L, SEEK_SET);
	fwrite(&tag, sizeof(uint8_t), sizeof(tag), binfile);

	fclose(binfile);

	return 0;
}

int main(int argc, char **argv)
{
	int c;
	char *kernel, *rootfs, *bin, *boardid, *chipid;
	uint32_t loadaddr, entry;

	kernel = rootfs = bin = boardid = chipid = NULL;
	entry = 0;

	loadaddr = IMAGETAG_DEFAULT_LOADADDR;

	printf("Broadcom image tagger - v0.1.0\n");
	printf("Copyright (C) 2008 Axel Gembe\n");

	while ((c = getopt(argc, argv, "i:f:o:b:c:l:e:h")) != -1) {
		switch (c) {
			case 'i':
				kernel = optarg;
				break;
			case 'f':
				rootfs = optarg;
				break;
			case 'o':
				bin = optarg;
				break;
			case 'b':
				boardid = optarg;
				break;
			case 'c':
				chipid = optarg;
				break;
			case 'l':
				loadaddr = strtoul(optarg, NULL, 16);
				break;
			case 'e':
				entry = strtoul(optarg, NULL, 16);
				break;
			case 'h':
			default:
				fprintf(stderr, "Usage: imagetag <parameters>\n");
				fprintf(stderr, "-i <kernel>   - The LZMA compressed kernel file to include in the image\n");
				fprintf(stderr, "-f <rootfs>   - The RootFS file to include in the image\n");
				fprintf(stderr, "-o <bin>      - The output file\n");
				fprintf(stderr, "-b <boardid>  - The board id to set in the image (i.e. \"96345GW2\")\n");
				fprintf(stderr, "-c <chipid>   - The chip id to set in the image (i.e. \"6345\")\n");
				fprintf(stderr, "-l <loadaddr> - Address where the kernel expects to be loaded (defaults to 0x80010000)\n");
				fprintf(stderr, "-e <entry>    - Address where the kernel entry point will end up\n");
				fprintf(stderr, "-h            - Displays this text\n");
				return 1;
		}
	}

	if (!boardid || !chipid) {
		fprintf(stderr, "You need to specify the board (-b) and chip id (-c)!\n");
		return 1;
	}

	if (entry == 0) {
		fprintf(stderr, "You need to specify the kernel entry (-e)\n");
		return 1;
	}

	return tagfile(kernel, rootfs, bin, boardid, chipid, loadaddr, entry);
}
