* very well-known)
*
* The following function creates a CRC32 table depending on whether
- * a big-endian (0x04c11db7) or little-endian (0xedb88320) CRC32 is
+ * a big-endian (0x04c11db7) or little-endian (0xedb88320) CRC32 is
* required. Admittedly, there are other CRC32 polynomials floating
* around, but Busybox doesn't use them.
*
* endian = 1: big-endian
* endian = 0: little-endian
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include <stdio.h>
-#include <stdlib.h>
#include "libbb.h"
-uint32_t *bb_crc32_filltable (int endian) {
-
- uint32_t *crc_table = xmalloc(256 * sizeof(uint32_t));
+uint32_t *global_crc32_table;
+
+uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
+{
uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
uint32_t c;
int i, j;
-
+
+ if (!crc_table)
+ crc_table = xmalloc(256 * sizeof(uint32_t));
+
for (i = 0; i < 256; i++) {
c = endian ? (i << 24) : i;
for (j = 8; j; j--) {
return crc_table - 256;
}
+
+uint32_t FAST_FUNC crc32_block_endian1(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
+{
+ const void *end = (uint8_t*)buf + len;
+
+ while (buf != end) {
+ val = (val << 8) ^ crc_table[(val >> 24) ^ *(uint8_t*)buf];
+ buf = (uint8_t*)buf + 1;
+ }
+ return val;
+}
+
+uint32_t FAST_FUNC crc32_block_endian0(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
+{
+ const void *end = (uint8_t*)buf + len;
+
+ while (buf != end) {
+ val = crc_table[(uint8_t)val ^ *(uint8_t*)buf] ^ (val >> 8);
+ buf = (uint8_t*)buf + 1;
+ }
+ return val;
+}