Increase the function of crc8 to use custom polynomials

N/A

Signed-off-by: zhouliang3 <zhouliang3@xiaomi.com>
Change-Id: I3c53bf25541c1811a05d025b39dfe24cb0613b72

include/crc8.h

@@ -62,6 +62,18 @@ uint8_t crc8part(FAR const uint8_t *src, size_t len, uint8_t crc8val);
 
 uint8_t crc8(FAR const uint8_t *src, size_t len);
 
+/****************************************************************************
+ * Name: crc8table
+ *
+ * Description:
+ *   Return a 8-bit CRC of the contents of the 'src' buffer, length 'len'
+ *   using a CRC with crc table used for calculation.
+ *
+ ****************************************************************************/
+
+uint8_t crc8table(const uint8_t table[256], const uint8_t *src,
+                  size_t len, uint8_t crc8val);
+
 /****************************************************************************
  * Name: crc8ccitt
  *

libs/libc/misc/Make.defs

@@ -46,8 +46,9 @@ endif
 
 # Add the miscellaneous C files to the build
 
-CSRCS += lib_crc64.c lib_crc32.c lib_crc16.c lib_crc8.c lib_crc8ccitt.c
 CSRCS += lib_dumpbuffer.c lib_dumpvbuffer.c lib_match.c lib_debug.c
+CSRCS += lib_crc64.c lib_crc32.c lib_crc16.c lib_crc8.c lib_crc8ccitt.c
+CSRCS += lib_crc8table.c
 
 # Keyboard driver encoder/decoder
 

libs/libc/misc/lib_crc8.c

@@ -103,15 +103,7 @@ static const uint8_t crc8_tab[256] =
 
 uint8_t crc8part(FAR const uint8_t *src, size_t len, uint8_t crc8val)
 {
-  size_t i;
+  return crc8table(crc8_tab, src, len, crc8val);
-
-  crc8val ^= 0xff;
-  for (i = 0; i < len; i++)
-    {
-      crc8val = crc8_tab[crc8val ^ src[i]];
-    }
-
-  return crc8val ^ 0xff;
 }
 
 /****************************************************************************

libs/libc/misc/lib_crc8ccitt.c

@@ -82,16 +82,7 @@ static const uint8_t crc8_tab[256] =
 
 uint8_t crc8ccittpart(FAR const uint8_t *src, size_t len, uint8_t crc8val)
 {
-  uint8_t *pos = (uint8_t *) src;
+  return crc8table(crc8_tab, src, len, crc8val);
-  uint8_t *end = pos + len;
-
-  while (pos < end)
-    {
-      crc8val = crc8_tab[crc8val ^ *pos];
-      pos++;
-    }
-
-  return crc8val;
 }
 
 /***************************************************************************

libs/libc/misc/lib_crc8table.c

@@ -0,0 +1,54 @@
+/****************************************************************************
+ * libs/libc/misc/lib_crc8table.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <crc8.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: crc8table
+ *
+ * Description:
+ *   Return a 8-bit CRC of the contents of the 'src' buffer, length 'len'
+ *   using a CRC with crc table used for calculation.
+ *
+ ****************************************************************************/
+
+uint8_t crc8table(const uint8_t table[256], const uint8_t *src,
+                  size_t len, uint8_t crc8val)
+{
+  size_t i;
+
+  crc8val ^= 0xff;
+  for (i = 0; i < len; i++)
+    {
+      crc8val = table[crc8val ^ src[i]];
+    }
+
+  return crc8val ^ 0xff;
+}