better keep_alive() handling

git-svn-id: svn://svn.berlios.de/openocd/trunk@1018 b42882b7-edfa-0310-969c-e2dbd0fdcd60

src/target/image.c

@@ -998,14 +998,13 @@ int image_close(image_t *image)
 	return ERROR_OK;
 }
 
-static u32 crc32_table[256] = {0, 0};
-
 int image_calculate_checksum(u8* buffer, u32 nbytes, u32* checksum)
 {
 	u32 crc = 0xffffffff;
+	LOG_DEBUG("Calculating checksum");
+
+	u32 crc32_table[256];
 
-	if (!crc32_table[1])
-	{
 	/* Initialize the CRC table and the decoding table.  */
 	int i, j;
 	unsigned int c;
@@ -1016,18 +1015,25 @@ int image_calculate_checksum(u8* buffer, u32 nbytes, u32* checksum)
 			c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
 		crc32_table[i] = c;
 	}
-	}
 
-	while (nbytes--)
+	while (nbytes>0)
+	{
+		int run=nbytes;
+		if (run>32768)
+		{
+			run=32768;
+		}
+		nbytes-=run;
+		while (run--)
 		{
 			/* as per gdb */
 			crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buffer++) & 255];
-		if ((nbytes%16384)==0)
-		{
-			keep_alive();
 		}
+		keep_alive();
 	}
 
+	LOG_DEBUG("Calculating checksum done");
+
 	*checksum = crc;
 	return ERROR_OK;
 }