iPXE
crc32.c
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1 /*
2  * Little-endian CRC32 implementation.
3  *
4  * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of the
9  * License, or any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19  * 02110-1301, USA.
20  */
21 
22 FILE_LICENCE ( GPL2_OR_LATER );
23 
24 #include <ipxe/crc32.h>
25 
26 #define CRCPOLY 0xedb88320
27 
28 /**
29  * Calculate 32-bit little-endian CRC checksum
30  *
31  * @v seed Initial value
32  * @v data Data to checksum
33  * @v len Length of data
34  *
35  * Usually @a seed is initially zero or all one bits, depending on the
36  * protocol. To continue a CRC checksum over multiple calls, pass the
37  * return value from one call as the @a seed parameter to the next.
38  */
39 u32 crc32_le ( u32 seed, const void *data, size_t len )
40 {
41  u32 crc = seed;
42  const u8 *src = data;
43  u32 mult;
44  int i;
45 
46  while ( len-- ) {
47  crc ^= *src++;
48  for ( i = 0; i < 8; i++ ) {
49  mult = ( crc & 1 ) ? CRCPOLY : 0;
50  crc = ( crc >> 1 ) ^ mult;
51  }
52  }
53 
54  return crc;
55 }
FILE_LICENCE(GPL2_OR_LATER)
u32 crc32_le(u32 seed, const void *data, size_t len)
Calculate 32-bit little-endian CRC checksum.
Definition: crc32.c:39
static __always_inline void off_t userptr_t src
Definition: efi_uaccess.h:66
#define CRCPOLY
Definition: crc32.c:26
uint32_t len
Length.
Definition: ena.h:14
struct arbelprm_port_state_change_st data
Message.
Definition: arbel.h:12
uint8_t u8
Definition: stdint.h:19
uint32_t u32
Definition: stdint.h:23