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comparison ostc4pack/src/crcmodel.h @ 161:b70fae5023b4 linux-build

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Add missing file for self build pack tools The added header was missing causing self building to fail. Simply added the missing file. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
author Jan Mulder <jlmulder@xs4all.nl>
date Thu, 21 Feb 2019 10:01:36 +0100
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80:cc2bb7bb8456 161:b70fae5023b4
1 /******************************************************************************/
2 /* */
3 /* Author : Ross Williams (ross@guest.adelaide.edu.au.). */
4 /* Date : 3 June 1993. */
5 /* Status : Public domain. */
6 /* */
7 /* Description : This is the header (.h) file for the reference */
8 /* implementation of the Rocksoft^tm Model CRC Algorithm. For more */
9 /* information on the Rocksoft^tm Model CRC Algorithm, see the document */
10 /* titled "A Painless Guide to CRC Error Detection Algorithms" by Ross */
11 /* Williams (ross@guest.adelaide.edu.au.). This document is likely to be in */
12 /* "ftp.adelaide.edu.au/pub/rocksoft". */
13 /* */
14 /* Note: Rocksoft is a trademark of Rocksoft Pty Ltd, Adelaide, Australia. */
15 /* */
16 /******************************************************************************/
17 /* */
18 /* How to Use This Package */
19 /* ----------------------- */
20 /* Step 1: Declare a variable of type cm_t. Declare another variable */
21 /* (p_cm say) of type p_cm_t and initialize it to point to the first */
22 /* variable (e.g. p_cm_t p_cm = &cm_t). */
23 /* */
24 /* Step 2: Assign values to the parameter fields of the structure. */
25 /* If you don't know what to assign, see the document cited earlier. */
26 /* For example: */
27 /* p_cm->cm_width = 16; */
28 /* p_cm->cm_poly = 0x8005L; */
29 /* p_cm->cm_init = 0L; */
30 /* p_cm->cm_refin = TRUE; */
31 /* p_cm->cm_refot = TRUE; */
32 /* p_cm->cm_xorot = 0L; */
33 /* Note: Poly is specified without its top bit (18005 becomes 8005). */
34 /* Note: Width is one bit less than the raw poly width. */
35 /* */
36 /* Step 3: Initialize the instance with a call cm_ini(p_cm); */
37 /* */
38 /* Step 4: Process zero or more message bytes by placing zero or more */
39 /* successive calls to cm_nxt. Example: cm_nxt(p_cm,ch); */
40 /* */
41 /* Step 5: Extract the CRC value at any time by calling crc = cm_crc(p_cm); */
42 /* If the CRC is a 16-bit value, it will be in the bottom 16 bits. */
43 /* */
44 /******************************************************************************/
45 /* */
46 /* Design Notes */
47 /* ------------ */
48 /* PORTABILITY: This package has been coded very conservatively so that */
49 /* it will run on as many machines as possible. For example, all external */
50 /* identifiers have been restricted to 6 characters and all internal ones to */
51 /* 8 characters. The prefix cm (for Crc Model) is used as an attempt to avoid */
52 /* namespace collisions. This package is endian independent. */
53 /* */
54 /* EFFICIENCY: This package (and its interface) is not designed for */
55 /* speed. The purpose of this package is to act as a well-defined reference */
56 /* model for the specification of CRC algorithms. If you want speed, cook up */
57 /* a specific table-driven implementation as described in the document cited */
58 /* above. This package is designed for validation only; if you have found or */
59 /* implemented a CRC algorithm and wish to describe it as a set of parameters */
60 /* to the Rocksoft^tm Model CRC Algorithm, your CRC algorithm implementation */
61 /* should behave identically to this package under those parameters. */
62 /* */
63 /******************************************************************************/
64
65 /* The following #ifndef encloses this entire */
66 /* header file, rendering it indempotent. */
67 #ifndef CM_DONE
68 #define CM_DONE
69
70 /******************************************************************************/
71
72 /* The following definitions are extracted from my style header file which */
73 /* would be cumbersome to distribute with this package. The DONE_STYLE is the */
74 /* idempotence symbol used in my style header file. */
75
76 #ifndef DONE_STYLE
77
78 typedef unsigned long ulong;
79 typedef unsigned bool;
80 typedef unsigned char *p_ubyte_;
81
82 #ifndef TRUE
83 #define FALSE 0
84 #define TRUE 1
85 #endif
86
87 /* Change to the second definition if you don't have prototypes. */
88 #define P_(A) A
89 /* #define P_(A) () */
90
91 /* Uncomment this definition if you don't have void. */
92 /* typedef int void; */
93
94 #endif
95
96 /******************************************************************************/
97
98 /* CRC Model Abstract Type */
99 /* ----------------------- */
100 /* The following type stores the context of an executing instance of the */
101 /* model algorithm. Most of the fields are model parameters which must be */
102 /* set before the first initializing call to cm_ini. */
103 typedef struct {
104 int cm_width; /* Parameter: Width in bits [8,32]. */
105 ulong cm_poly; /* Parameter: The algorithm's polynomial. */
106 ulong cm_init; /* Parameter: Initial register value. */
107 bool cm_refin; /* Parameter: Reflect input bytes? */
108 bool cm_refot; /* Parameter: Reflect output CRC? */
109 ulong cm_xorot; /* Parameter: XOR this to output CRC. */
110
111 ulong cm_reg; /* Context: Context during execution. */
112 } cm_t;
113 typedef cm_t *p_cm_t;
114
115 /******************************************************************************/
116
117 /* Functions That Implement The Model */
118 /* ---------------------------------- */
119 /* The following functions animate the cm_t abstraction. */
120
121 void cm_ini P_((p_cm_t p_cm));
122 /* Initializes the argument CRC model instance. */
123 /* All parameter fields must be set before calling this. */
124
125 void cm_nxt P_((p_cm_t p_cm, int ch));
126 /* Processes a single message byte [0,255]. */
127
128 void cm_blk P_((p_cm_t p_cm, p_ubyte_ blk_adr, ulong blk_len));
129 /* Processes a block of message bytes. */
130
131 ulong cm_crc P_((p_cm_t p_cm));
132 /* Returns the CRC value for the message bytes processed so far. */
133
134 /******************************************************************************/
135
136 /* Functions For Table Calculation */
137 /* ------------------------------- */
138 /* The following function can be used to calculate a CRC lookup table. */
139 /* It can also be used at run-time to create or check static tables. */
140
141 ulong cm_tab P_((p_cm_t p_cm, int index));
142 /* Returns the i'th entry for the lookup table for the specified algorithm. */
143 /* The function examines the fields cm_width, cm_poly, cm_refin, and the */
144 /* argument table index in the range [0,255] and returns the table entry in */
145 /* the bottom cm_width bytes of the return value. */
146
147 /******************************************************************************/
148
149 /* End of the header file idempotence #ifndef */
150 #endif