+++ /dev/null
-/* Copyright abandoned; this code is in the public domain. */
-/* Provided to GNUnet by peter@horizon.com */
-
-/*
- * Adapted for GeekOS by David Hovemeyer
- * Code downloaded from OVM (http://www.ovmj.org)
- */
-
-#include <geekos/crc32.h>
-#include <geekos/kassert.h>
-#include <geekos/debug.h>
-
-#define POLYNOMIAL (ulong_t)0xedb88320
-static ulong_t crc_table[256];
-
-/*
- * This routine writes each crc_table entry exactly once,
- * with the correct final value. Thus, it is safe to call
- * even on a table that someone else is using concurrently.
- */
-void Init_CRC32(void) {
- unsigned int i, j;
- ulong_t h = 1;
- PrintBoth("Initializing CRC32\n");
- crc_table[0] = 0;
- for (i = 128; i; i >>= 1) {
- h = (h >> 1) ^ ((h & 1) ? POLYNOMIAL : 0);
- /* h is now crc_table[i] */
- for (j = 0; j < 256; j += 2*i)
- crc_table[i+j] = crc_table[j] ^ h;
- }
-}
-
-/*
- * This computes the standard preset and inverted CRC, as used
- * by most networking standards. Start by passing in an initial
- * chaining value of 0, and then pass in the return value from the
- * previous crc32() call. The final return value is the CRC.
- * Note that this is a little-endian CRC, which is best used with
- * data transmitted lsbit-first, and it should, itself, be appended
- * to data in little-endian byte and bit order to preserve the
- * property of detecting all burst errors of length 32 bits or less.
- */
-ulong_t crc32(ulong_t crc, char const *buf, size_t len) {
- KASSERT(crc_table[255] != 0);
- crc ^= 0xffffffff;
- while (len--)
- crc = (crc >> 8) ^ crc_table[(crc ^ *buf++) & 0xff];
- return crc ^ 0xffffffff;
-}
-
-/* end of crc32.c */