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author | James Buren <braewoods+rb@braewoods.net> | 2021-07-30 23:11:49 +0000 |
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committer | James Buren <braewoods+rb@braewoods.net> | 2021-07-30 23:11:49 +0000 |
commit | f32fc84ef6c0b95eec85b4436623a04d0b0bd6cb (patch) | |
tree | a5d6ca620ac6ce07b93b74f386ce21492b56595b /firmware | |
parent | ee05b8574a84fa7a46d6f0453b60a611c1bcc813 (diff) | |
download | rockbox-f32fc84ef6c0b95eec85b4436623a04d0b0bd6cb.tar.gz rockbox-f32fc84ef6c0b95eec85b4436623a04d0b0bd6cb.zip |
adler32: import adapted implementation from tinf/zlib
This adds an adapted version of the adler32 algorithm from tinf/zlib
which will be necessary to support ZLIB deflate streams in the future.
Change-Id: Ie60e15acb288acf56a2d44e3d3e912e1b3eb2216
Diffstat (limited to 'firmware')
-rw-r--r-- | firmware/SOURCES | 1 | ||||
-rw-r--r-- | firmware/common/adler32.c | 75 | ||||
-rw-r--r-- | firmware/include/adler32.h | 29 |
3 files changed, 105 insertions, 0 deletions
diff --git a/firmware/SOURCES b/firmware/SOURCES index fc194fe640..71a11429cd 100644 --- a/firmware/SOURCES +++ b/firmware/SOURCES | |||
@@ -269,6 +269,7 @@ common/timefuncs.c | |||
269 | common/unicode.c | 269 | common/unicode.c |
270 | common/vuprintf.c | 270 | common/vuprintf.c |
271 | common/zip.c | 271 | common/zip.c |
272 | common/adler32.c | ||
272 | 273 | ||
273 | /* Display */ | 274 | /* Display */ |
274 | scroll_engine.c | 275 | scroll_engine.c |
diff --git a/firmware/common/adler32.c b/firmware/common/adler32.c new file mode 100644 index 0000000000..8f5f85b453 --- /dev/null +++ b/firmware/common/adler32.c | |||
@@ -0,0 +1,75 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2021 James Buren (adaptations from tinf/zlib) | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | #include "adler32.h" | ||
23 | #include "system.h" | ||
24 | |||
25 | /* adler_32 (derived from tinf adler32 which was taken from zlib) | ||
26 | * Adler-32 algorithm taken from the zlib source, which is | ||
27 | * Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler | ||
28 | */ | ||
29 | uint32_t adler_32(const void *src, uint32_t len, uint32_t adler32) | ||
30 | { | ||
31 | const unsigned char *buf = (const unsigned char *)src; | ||
32 | uint32_t s1 = (adler32 & 0xffff); | ||
33 | uint32_t s2 = (adler32 >> 16); | ||
34 | |||
35 | enum { | ||
36 | A32_BASE = 65521, | ||
37 | A32_NMAX = 5552, | ||
38 | }; | ||
39 | |||
40 | while (len > 0) { | ||
41 | uint32_t k = MIN(len, A32_NMAX); | ||
42 | uint32_t i; | ||
43 | |||
44 | for (i = k / 16; i; --i, buf += 16) { | ||
45 | s2 += s1 += buf[0]; | ||
46 | s2 += s1 += buf[1]; | ||
47 | s2 += s1 += buf[2]; | ||
48 | s2 += s1 += buf[3]; | ||
49 | s2 += s1 += buf[4]; | ||
50 | s2 += s1 += buf[5]; | ||
51 | s2 += s1 += buf[6]; | ||
52 | s2 += s1 += buf[7]; | ||
53 | s2 += s1 += buf[8]; | ||
54 | s2 += s1 += buf[9]; | ||
55 | s2 += s1 += buf[10]; | ||
56 | s2 += s1 += buf[11]; | ||
57 | s2 += s1 += buf[12]; | ||
58 | s2 += s1 += buf[13]; | ||
59 | s2 += s1 += buf[14]; | ||
60 | s2 += s1 += buf[15]; | ||
61 | } | ||
62 | |||
63 | for (i = k % 16; i; --i) { | ||
64 | s1 += *buf++; | ||
65 | s2 += s1; | ||
66 | } | ||
67 | |||
68 | s1 %= A32_BASE; | ||
69 | s2 %= A32_BASE; | ||
70 | |||
71 | len -= k; | ||
72 | } | ||
73 | |||
74 | return (s1 | (s2 << 16)); | ||
75 | } | ||
diff --git a/firmware/include/adler32.h b/firmware/include/adler32.h new file mode 100644 index 0000000000..cd5302e869 --- /dev/null +++ b/firmware/include/adler32.h | |||
@@ -0,0 +1,29 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2021 James Buren (adaptations from tinf/zlib) | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | #include <stdint.h> | ||
23 | |||
24 | #ifndef _ADLER32_H | ||
25 | #define _ADLER32_H | ||
26 | |||
27 | uint32_t adler_32(const void *src, uint32_t len, uint32_t adler32); | ||
28 | |||
29 | #endif | ||