common/commonutil.c

   1 //-----------------------------------------------------------------------------
   2 // Jonathan Westhues, Sept 2005
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // Utility functions used in many places, not specific to any piece of code.
   9 //-----------------------------------------------------------------------------
  10 #include "commonutil.h"
  11 #include <string.h>
  12
  13 /* Similar to FpgaGatherVersion this formats stored version information
  14  * into a string representation. It takes a pointer to the struct version_information,
  15  * verifies the magic properties, then stores a formatted string, prefixed by
  16  * prefix in dst.
  17  */
  18 void FormatVersionInformation(char *dst, int len, const char *prefix, void *version_info) {
  19     struct version_information *v = (struct version_information *)version_info;
  20     dst[0] = 0;
  21     strncat(dst, prefix, len - 1);
  22     if (v->magic != VERSION_INFORMATION_MAGIC) {
  23         strncat(dst, "Missing/Invalid version information", len - strlen(dst) - 1);
  24         return;
  25     }
  26     if (v->versionversion != 1) {
  27         strncat(dst, "Version information not understood", len - strlen(dst) - 1);
  28         return;
  29     }
  30     if (!v->present) {
  31         strncat(dst, "Version information not available", len - strlen(dst) - 1);
  32         return;
  33     }
  34
  35     strncat(dst, v->gitversion, len - strlen(dst) - 1);
  36     if (v->clean == 0) {
  37         strncat(dst, "-unclean", len - strlen(dst) - 1);
  38     } else if (v->clean == 2) {
  39         strncat(dst, "-suspect", len - strlen(dst) - 1);
  40     }
  41
  42     strncat(dst, " ", len - strlen(dst) - 1);
  43     strncat(dst, v->buildtime, len - strlen(dst) - 1);
  44 }
  45
  46 /*
  47  ref  http://www.csm.ornl.gov/~dunigan/crc.html
  48  Returns the value v with the bottom b [0,32] bits reflected.
  49  Example: reflect(0x3e23L,3) == 0x3e26
  50 */
  51 uint32_t reflect(uint32_t v, int b) {
  52     uint32_t t = v;
  53     for (int i = 0; i < b; ++i) {
  54         if (t & 1)
  55             v |=  BITMASK((b - 1) - i);
  56         else
  57             v &= ~BITMASK((b - 1) - i);
  58         t >>= 1;
  59     }
  60     return v;
  61 }
  62
  63 // https://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
  64
  65 // Reverse the bits in a byte with 3 operations (64-bit multiply and modulus division):
  66 uint8_t reflect8(uint8_t b) {
  67     return (b * 0x0202020202ULL & 0x010884422010ULL) % 1023;
  68 }
  69
  70
  71 // Reverse the bits in a byte with 4 operations (64-bit multiply, no division):
  72 /*
  73 uint8_t reflect8(uint8_t b) {
  74     return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
  75 }
  76 */
  77
  78 uint16_t reflect16(uint16_t b) {
  79     uint16_t v = 0;
  80     v |= (b & 0x8000) >> 15;
  81     v |= (b & 0x4000) >> 13;
  82     v |= (b & 0x2000) >> 11;
  83     v |= (b & 0x1000) >> 9;
  84     v |= (b & 0x0800) >> 7;
  85     v |= (b & 0x0400) >> 5;
  86     v |= (b & 0x0200) >> 3;
  87     v |= (b & 0x0100) >> 1;
  88
  89     v |= (b & 0x0080) << 1;
  90     v |= (b & 0x0040) << 3;
  91     v |= (b & 0x0020) << 5;
  92     v |= (b & 0x0010) << 7;
  93     v |= (b & 0x0008) << 9;
  94     v |= (b & 0x0004) << 11;
  95     v |= (b & 0x0002) << 13;
  96     v |= (b & 0x0001) << 15;
  97     return v;
  98 }
  99
 100 uint32_t reflect32(uint32_t b) {
 101     // https://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
 102     uint32_t v = b; // 32-bit word to reverse bit order
 103     // swap odd and even bits
 104     v = ((v >> 1) & 0x55555555) | ((v & 0x55555555) << 1);
 105     // swap consecutive pairs
 106     v = ((v >> 2) & 0x33333333) | ((v & 0x33333333) << 2);
 107     // swap nibbles ...
 108     v = ((v >> 4) & 0x0F0F0F0F) | ((v & 0x0F0F0F0F) << 4);
 109     // swap bytes
 110     v = ((v >> 8) & 0x00FF00FF) | ((v & 0x00FF00FF) << 8);
 111     // swap 2-byte long pairs
 112     v = (v >> 16) | (v               << 16);
 113     return v;
 114 }
 115
 116 void num_to_bytes(uint64_t n, size_t len, uint8_t *dest) {
 117     while (len--) {
 118         dest[len] = (uint8_t) n;
 119         n >>= 8;
 120     }
 121 }
 122
 123 uint64_t bytes_to_num(uint8_t *src, size_t len) {
 124     uint64_t num = 0;
 125     while (len--) {
 126         num = (num << 8) | (*src);
 127         src++;
 128     }
 129     return num;
 130 }
 131
 132 // RotateLeft - Ultralight, Desfire
 133 void rol(uint8_t *data, const size_t len) {
 134     uint8_t first = data[0];
 135     for (size_t i = 0; i < len - 1; i++) {
 136         data[i] = data[i + 1];
 137     }
 138     data[len - 1] = first;
 139 }
 140
 141 void lsl(uint8_t *data, size_t len) {
 142     for (size_t n = 0; n < len - 1; n++) {
 143         data[n] = (data[n] << 1) | (data[n + 1] >> 7);
 144     }
 145     data[len - 1] <<= 1;
 146 }
 147
 148
 149 // BSWAP24 of array[3]
 150 uint32_t le24toh(uint8_t data[3]) {
 151     return (data[2] << 16) | (data[1] << 8) | data[0];
 152 }
 153
 154 // BSWAP24, take u32, output array
 155 void htole24(uint32_t val, uint8_t data[3]) {
 156     data[0] = (uint8_t) val;
 157     data[1] = (uint8_t)(val >> 8);
 158     data[2] = (uint8_t)(val >> 16);
 159 }
 160
 161
 162 // ROL on u32
 163 uint32_t rotl(uint32_t a, uint8_t n) {
 164     n &= 31;
 165     return (a << n) | (a >> (32 - n));
 166 }
 167
 168 // ROR on u32
 169 uint32_t rotr(uint32_t a, uint8_t n) {
 170     n &= 31;
 171     return (a >> n) | (a << (32 - n));
 172 }