X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/rsbs2/blobdiff_plain/6d8c2f71b2e7a4e42390a95945d9d0342d53cf90..3d45f4d10fb15049251ea82876cc70a19a0e0700:/rsb-lz.c

diff --git a/rsb-lz.c b/rsb-lz.c
index 7b94aef..2e50252 100644
--- a/rsb-lz.c
+++ b/rsb-lz.c
@@ -98,87 +98,180 @@ void write_byte(unsigned char byte, struct data_out_s *data_out)
 	data_out->pos++;
 }
 
-void lz_expand(struct data_in_s *r10_data, struct data_out_s *data_out)
+void lz_expand(struct data_in_s *data_in, struct data_out_s *data_out)
 {
-	unsigned int r5;
-	unsigned int r2;
-	unsigned char r4;
-	unsigned int r6;
-	unsigned int r7;
-	unsigned int r11;
-	unsigned char window[1024];
+	unsigned int pos;
+	unsigned int wordoffset;
+	unsigned int i;
+	unsigned char byte;
+	unsigned int wordlen;
+	unsigned char buf[1024];
 
-	r5 = 1;
+	pos = 1;
 
 	while (1) {
 		while (1) {
-			r2 = get_next_bit(r10_data);
-			if (r2 == 0)
+			/* Compressed/uncompressed? */
+			if (get_next_bit(data_in) == 0)
 				break;
 
-			r2 = get_next_bits(r10_data, 8) & 0xff;
+			/* Uncompressed byte */
+			byte = get_next_bits(data_in, 8);
+
+			write_byte(byte, data_out);
 
-			write_byte(r2, data_out);
-			window[r5] = r2 & 0xff;
-			r5 = (r5 + 1) & 0x3ff;
+			/* Save byte in buffer, to be reused later */
+			buf[pos] = byte;
+			pos = (pos + 1) & 0x3ff;
 		}
 
-		r11 = get_next_bits(r10_data, 0x0a);
-		if(r11 == 0)
+		/* offset for start of dictionary word */
+		wordoffset = get_next_bits(data_in, 0x0a);
+		if(wordoffset == 0)
 			return;
 
-		r2 = get_next_bits(r10_data, 0x04);
-		r7 = r2 + 1;
-		r6 = 0;
-		while (r6 <= r7) {
-			r2 = (r6 + r11) & 0x3ff;
-			r4 = window[r2];
-			write_byte(r4, data_out);
-			window[r5] = r4;
-			r5 = (r5 + 1) & 0x3ff;
-			r6++;
+		/* length of dictionary word used */
+		wordlen = get_next_bits(data_in, 0x04) + 1;
+		for (i = 0; i <= wordlen ; i++) {
+			/* lookup dictionary byte */
+			byte = buf[(wordoffset + i) & 0x3ff];
+			write_byte(byte, data_out);
+			/* Save byte in buffer, to be reused later */
+			buf[pos] = byte;
+			pos = (pos + 1) & 0x3ff;
 		}
 	}
 }
 
-/* Checksum is only used for the compressed firmware in 'firmware' */
-#if 0
-unsigned int crc_check_59684(unsigned char *arg1, unsigned int arg2, unsigned int magic)
+void set_next_bit(unsigned char *buf, unsigned int set, unsigned int *currbit) {
+	unsigned char *pos;
+	unsigned char bitpos;
+
+	if (set) {
+		pos = buf + ((*currbit) / 8);
+		bitpos = 0x80 >> ((*currbit) % 8);
+		*pos |= bitpos;
+	}
+
+	*currbit = *currbit + 1;
+}
+
+void write_bits(unsigned char *buf, unsigned int data, unsigned int bits, unsigned int *currbit) {
+	int i;
+	unsigned int bitpos;
+
+	bitpos = 1 << (bits - 1);
+
+	for (i = 0; i < bits; i++) {
+		set_next_bit(buf, data & bitpos, currbit);
+		bitpos >>= 1;
+	}
+}
+
+unsigned char *compress_lz(unsigned char *inbuf, int inlen, int *outlen)
 {
-	unsigned int r3;
-	unsigned int r4;
-	unsigned int r5;
+	unsigned char *end = inbuf + inlen;
+	unsigned char *outbuf;
+	unsigned char window[1024];
+	int pos = 0;
+	int fill = 0;
+	unsigned int currbit = 0;
+	int offset;
+	int wordlen;
+	int found;
+	int i;
+
+	if ((outbuf = malloc((inlen * 2) + 4)) == NULL) {
+		perror("malloc");
+	}
 
-#if 0
-	if (r0 < 0xc0000000)
-		return 1;
-#endif
+	*((unsigned int*)outbuf) = LZ_MAGIC;
+	currbit = 8 * 8;
+
+	while(inbuf < end) {
+		found = 0;
+		for (wordlen = 17; wordlen > 1; wordlen--) {
+			for (offset = 1; offset < ((fill < 1023) ? fill : 1023); offset++) {
+				if ((fill < 1023) &&
+				    (wordlen + offset > fill))
+					break;
+
+				for (i = 0; i < wordlen; i++) {
+					if (inbuf[i] != window[(offset + i) & 0x3ff]) {
+						break;
+					}
+				}
+				if (i == wordlen)
+					found = 1;
+			}
+			if (found)
+				break;
+		}
+
+		if (found) {
+			write_bits(outbuf, 0x00, 0x01, &currbit);
+			write_bits(outbuf, offset, 0x0a, &currbit);
+			write_bits(outbuf, wordlen - 1, 0x04, &currbit);
+			for (i = 0; i < wordlen; i++) {
+				window[pos] = *(inbuf + i);
+				pos = (pos + 1) & 0x3ff;
+			}
+			inbuf += wordlen;
+
+			if (fill < sizeof(window))
+				fill += wordlen;
+		} else {
+			write_bits(outbuf, 0x01, 0x01, &currbit);
+			write_bits(outbuf, *inbuf, 0x08, &currbit);
+			window[pos] = *inbuf;
+			pos = (pos + 1) & 0x3ff;
+			inbuf++;
+			if (fill < sizeof(window))
+				fill++;
+		}
+	}
 
-	/* ??? */
-	r4 = *((unsigned int*)arg1 + 0x20);
-	r5 = *((unsigned int*)arg1 + 0x24);
+	write_bits(outbuf, 0x00, 0x01, &currbit);
+	write_bits(outbuf, 0x00, 0x0a, &currbit);
 
-	printf("magic: 0x%08x <-> 0x%08x\n", r5, magic);
-	if (r5 != magic)
+	*outlen = (currbit / 8) + 1;
+
+	*((unsigned int*)(outbuf + 4)) = *outlen;
+
+	return outbuf;
+}
+
+/* Checksum is only used for the compressed firmware in 'firmware' */
+unsigned int crc_check(unsigned char *buf, unsigned int len, unsigned int magic)
+{
+	unsigned int file_crc;
+	unsigned int my_len;
+	unsigned int crc;
+	unsigned int my_magic;
+
+	my_len = *((unsigned int*)(buf + 0x20));
+	my_magic = *((unsigned int*)(buf + 0x24));
+
+	if (my_magic != magic) {
+		printf("\nmagic: 0x%08x <-> 0x%08x\n", my_magic, magic);
 		return 2;
+	}
 	
-	if (arg2 >= r4)
-		r5 = 0;
-	else
+	if (len < my_len)
 		return 3;
 
-	r5 = ~rsb_crc(~0x00, arg1, r4);
-	r3 = *((unsigned int*)(arg1 + r4));
-	printf("Checksums: 0x%02x <-> 0x%02x\n", r5, r3);
+	crc = ~rsb_crc(~0x00, buf, len);
+	file_crc = *((unsigned int*)(buf + len));
 
-	if (r3 == r5)
-		return 0;
+	if (file_crc != crc) {
+		printf("\nChecksums: 0x%08x <-> 0x%08x!\n", crc, file_crc);
+		return 4;
+	}
 
-	return 4;
+	return 0;
 }
-#endif
 
-void extract_lz_file(unsigned char *inbuf, unsigned char *name)
+void extract_lz_file(unsigned char *inbuf, unsigned char *name, unsigned char check_crc)
 {
 	unsigned int len;
 	unsigned char *outbuf;
@@ -208,16 +301,17 @@ void extract_lz_file(unsigned char *inbuf, unsigned char *name)
 
 	lz_expand(&data_in, &data_out);
 
-#if 0
-	/* Checksum is only used for the compressed firmware in 'firmware' */
-	r3 = r7 + 0x20;
-	r5 = *((unsigned int*)r3);
+	if (check_crc) {
+		unsigned int crclen;
+		int ret;
 
-	if ((ret = crc_check_59684(r7, r5, 0x46335053)) != 0) {
-		printf("crc_check return: %d\n", ret);
-		err_exit(__func__);
+		crclen = *((unsigned int*)(outbuf + 0x20));
+
+		if ((ret = crc_check(outbuf, crclen, 0x46335053)) != 0) {
+			printf("crc_check return: %d\n", ret);
+			err_exit(__func__);
+		}
 	}
-#endif
 
 	write_file((char*)name, outbuf, len);