From: Michael Gernoth <michael@gernoth.net>
Date: Fri, 30 Jan 2009 20:38:12 +0000 (+0100)
Subject: don't implement checksum algorithm twice
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/rsbs2/commitdiff_plain/b4de99235c55fea1a73a8fe763d5c37830e07a08

don't implement checksum algorithm twice
---

diff --git a/rsb-crc.c b/rsb-crc.c
index 00b341f..719d682 100644
--- a/rsb-crc.c
+++ b/rsb-crc.c
@@ -117,17 +117,9 @@ unsigned int rsb_crc(unsigned int r11_crc, unsigned char *r10_buf, unsigned int
 
 unsigned int rsb_crc2(unsigned char *r0_buf, unsigned int r1_buflen, unsigned int r2_magic, unsigned int *crc_out) {
 	int r8_ret = 1;
-	unsigned int r3_pos = 0xc0000000;
 	unsigned int r4_len;
 	unsigned int r5_crc;
-	unsigned int r6;
-	unsigned int r9;
-	unsigned int carry;
-
-#if 0
-	if (r0_buf <= r3_pos)
-		return 1; /* Not in RAM */
-#endif
+	unsigned int file_crc;
 
 	r4_len = *(unsigned int*)(r0_buf + 0x20);
 
@@ -139,36 +131,12 @@ unsigned int rsb_crc2(unsigned char *r0_buf, unsigned int r1_buflen, unsigned in
 	
 	r8_ret = 4;
 
-	r3_pos = (unsigned int)r0_buf;
-	r4_len += r3_pos;
-	
-	r5_crc = ~0x0;
-
-	while (r3_pos < r4_len) {
-		r9 = r3_pos & (~0x3);
-		r6 = *((unsigned int*)r9);
-		r9 = r3_pos & 0x3;
-		r9 = r9 << 0x3;
-		r6 = r6 >> r9;
-		r5_crc = r5_crc ^ (r6 << 24);
-		r6 = 0x8;
-
-		do {
-			carry = r5_crc & 0x80000000;
-			r5_crc = r5_crc << 1;
-			if (carry)
-				r5_crc = r5_crc ^ POLY;
-			r6--;
-		} while(r6);
-		r3_pos++;
-	}
-
-	r5_crc = ~r5_crc;
+	r5_crc = ~rsb_crc(~0x0, r0_buf, r4_len);
 	*crc_out = r5_crc;
 
-	r3_pos = *((unsigned int*)r4_len);
+	file_crc = *((unsigned int*)(r0_buf + r4_len));
 
-	if (r3_pos == r5_crc)
+	if (file_crc == r5_crc)
 		r8_ret = 0;
 
 	return r8_ret;