move common util fcts to /common to avoid common files (e.g. crc) to depend on non-common files

common/commonutil.c

@@ -0,0 +1,89 @@
+//-----------------------------------------------------------------------------
+// Jonathan Westhues, Sept 2005
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Utility functions used in many places, not specific to any piece of code.
+//-----------------------------------------------------------------------------
+#include "commonutil.h"
+
+/*
+ ref  http://www.csm.ornl.gov/~dunigan/crc.html
+ Returns the value v with the bottom b [0,32] bits reflected.
+ Example: reflect(0x3e23L,3) == 0x3e26
+*/
+uint32_t reflect(uint32_t v, int b) {
+    uint32_t t = v;
+    for (int i = 0; i < b; ++i) {
+        if (t & 1)
+            v |=  BITMASK((b - 1) - i);
+        else
+            v &= ~BITMASK((b - 1) - i);
+        t >>= 1;
+    }
+    return v;
+}
+
+uint8_t reflect8(uint8_t b) {
+    return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
+}
+uint16_t reflect16(uint16_t b) {
+    uint16_t v = 0;
+    v |= (b & 0x8000) >> 15;
+    v |= (b & 0x4000) >> 13;
+    v |= (b & 0x2000) >> 11;
+    v |= (b & 0x1000) >> 9;
+    v |= (b & 0x0800) >> 7;
+    v |= (b & 0x0400) >> 5;
+    v |= (b & 0x0200) >> 3;
+    v |= (b & 0x0100) >> 1;
+
+    v |= (b & 0x0080) << 1;
+    v |= (b & 0x0040) << 3;
+    v |= (b & 0x0020) << 5;
+    v |= (b & 0x0010) << 7;
+    v |= (b & 0x0008) << 9;
+    v |= (b & 0x0004) << 11;
+    v |= (b & 0x0002) << 13;
+    v |= (b & 0x0001) << 15;
+    return v;
+}
+
+void num_to_bytes(uint64_t n, size_t len, uint8_t *dest) {
+    while (len--) {
+        dest[len] = (uint8_t) n;
+        n >>= 8;
+    }
+}
+
+uint64_t bytes_to_num(uint8_t *src, size_t len) {
+    uint64_t num = 0;
+    while (len--) {
+        num = (num << 8) | (*src);
+        src++;
+    }
+    return num;
+}
+
+// RotateLeft - Ultralight, Desfire
+void rol(uint8_t *data, const size_t len) {
+    uint8_t first = data[0];
+    for (size_t i = 0; i < len - 1; i++) {
+        data[i] = data[i + 1];
+    }
+    data[len - 1] = first;
+}
+
+void lsl(uint8_t *data, size_t len) {
+    for (size_t n = 0; n < len - 1; n++) {
+        data[n] = (data[n] << 1) | (data[n + 1] >> 7);
+    }
+    data[len - 1] <<= 1;
+}
+
+int32_t le24toh(uint8_t data[3]) {
+    return (data[2] << 16) | (data[1] << 8) | data[0];
+}
+