# HG changeset patch
# User jld
# Date 1251269651 0
# Node ID 3fa8710867ea0c1e93bc7fb491fddb20489d758d
# Parent  7a3b9a2f019b1de8d503f873ccfde678b3537595
* include/crc.h, src/crc16.c:  Add cyg_crc16_accumulate() to continue a
  previous crc calculation.
* tests/crc_test.c: Extend to test cyg_crc16_accumulate().

diff --git a/packages/services/crc/current/ChangeLog b/packages/services/crc/current/ChangeLog
--- a/packages/services/crc/current/ChangeLog
+++ b/packages/services/crc/current/ChangeLog
@@ -1,3 +1,9 @@
+2009-08-26  Simon Kallweit  <simon.kallweit@intefo.ch>
+
+	* include/crc.h, src/crc16.c:  Add cyg_crc16_accumulate() to continue
+	a previous crc calculation.
+	* tests/crc_test.c: Extend to test cyg_crc16_accumulate().
+
 2005-08-03  Andrew Lunn  <andrew.lunn@ascom.ch>
 
 	* tests/crc_test.c: casts to make it gcc 4.0.1 frendly.
@@ -42,7 +48,7 @@ 2002-08-07  Andrew Lunn  <andrew.lunn@as
 // ####GPLCOPYRIGHTBEGIN####                                                
 // -------------------------------------------                              
 // This file is part of eCos, the Embedded Configurable Operating System.   
-// Copyright (C) 2002 Free Software Foundation, Inc.                        
+// Copyright (C) 2002, 2009 Free Software Foundation, Inc.                        
 //
 // This program is free software; you can redistribute it and/or modify     
 // it under the terms of the GNU General Public License as published by     
diff --git a/packages/services/crc/current/include/crc.h b/packages/services/crc/current/include/crc.h
--- a/packages/services/crc/current/include/crc.h
+++ b/packages/services/crc/current/include/crc.h
@@ -8,7 +8,7 @@
 // ####ECOSGPLCOPYRIGHTBEGIN####                                            
 // -------------------------------------------                              
 // This file is part of eCos, the Embedded Configurable Operating System.   
-// Copyright (C) 2002 Free Software Foundation, Inc.                        
+// Copyright (C) 2002, 2009 Free Software Foundation, Inc.                        
 //
 // eCos is free software; you can redistribute it and/or modify it under    
 // the terms of the GNU General Public License as published by the Free     
@@ -96,6 +96,9 @@ cyg_ether_crc32_accumulate(cyg_uint32 cr
 __externC cyg_uint16
 cyg_crc16(unsigned char *s, int len);
 
+__externC cyg_uint16
+cyg_crc16_accumulate(cyg_uint16 crc, unsigned char *s, int len);
+
 #endif // _SERVICES_CRC_CRC_H_
 
 
diff --git a/packages/services/crc/current/src/crc16.c b/packages/services/crc/current/src/crc16.c
--- a/packages/services/crc/current/src/crc16.c
+++ b/packages/services/crc/current/src/crc16.c
@@ -8,7 +8,7 @@
 // ####ECOSGPLCOPYRIGHTBEGIN####                                            
 // -------------------------------------------                              
 // This file is part of eCos, the Embedded Configurable Operating System.   
-// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2009 Free Software Foundation, Inc.
 //
 // eCos is free software; you can redistribute it and/or modify it under    
 // the terms of the GNU General Public License as published by the Free     
@@ -92,13 +92,16 @@ static const cyg_uint16 crc16_tab[] = {
 cyg_uint16
 cyg_crc16(unsigned char *buf, int len)
 {
-    int i;
-    cyg_uint16 cksum;
-
-    cksum = 0;
-    for (i = 0;  i < len;  i++) {
-        cksum = crc16_tab[((cksum>>8) ^ *buf++) & 0xFF] ^ (cksum << 8);
-    }
-    return cksum;
+    return cyg_crc16_accumulate(0, buf, len);
 }
 
+cyg_uint16
+cyg_crc16_accumulate(cyg_uint16 crc16val, unsigned char *buf, int len)
+{
+    int i;
+
+    for (i = 0;  i < len;  i++) {
+        crc16val = crc16_tab[((crc16val>>8) ^ *buf++) & 0xFF] ^ (crc16val << 8);
+    }
+    return crc16val;
+}
diff --git a/packages/services/crc/current/tests/crc_test.c b/packages/services/crc/current/tests/crc_test.c
--- a/packages/services/crc/current/tests/crc_test.c
+++ b/packages/services/crc/current/tests/crc_test.c
@@ -8,7 +8,7 @@
 // ####ECOSGPLCOPYRIGHTBEGIN####                                            
 // -------------------------------------------                              
 // This file is part of eCos, the Embedded Configurable Operating System.   
-// Copyright (C) 2002 Free Software Foundation, Inc.                        
+// Copyright (C) 2002, 2009 Free Software Foundation, Inc.                        
 //
 // eCos is free software; you can redistribute it and/or modify it under    
 // the terms of the GNU General Public License as published by the Free     
@@ -125,10 +125,25 @@ cyg_start( void )
     CYG_TEST_PASS("Gary S. Browns' crc32 accumulate calculation");
   }
     
-  if (32256UL != cyg_crc16((unsigned char *)license_txt,
-                           sizeof(license_txt)-1)) {
-    CYG_TEST_FAIL_FINISH("Wrong 16bit CRC calculation");
+  if (32256 != cyg_crc16((unsigned char *)license_txt,
+                          sizeof(license_txt)-1)) {
+    CYG_TEST_FAIL("Wrong 16bit CRC calculation");
+  } else {
+    CYG_TEST_PASS("16bit CRC calculation");
+  }
+  
+  if (0 != cyg_crc16_accumulate(0,0,0)) {
+    CYG_TEST_FAIL("16bit CRC accumulate setup");
   } else {
-    CYG_TEST_PASS_FINISH("16bit CRC calculation");
+    crc1= cyg_crc16_accumulate(0, (unsigned char *)license_txt,
+                                   sizeof(license_txt)-1);
+    crc2 = cyg_crc16_accumulate(crc1, (unsigned char *)license_txt,
+                                       sizeof(license_txt)-1);
+    
+    if ((32256 != crc1) || (48052 != crc2)) {
+      CYG_TEST_FAIL_FINISH("Wrong 16bit CRC accumulate");
+    } else {
+      CYG_TEST_PASS_FINISH("16bit CRC accumulate");
+    }
   }
 }