1 files changed, 49 insertions, 0 deletions
diff --git a/tools/ioemu/iodev/crc32.cc b/tools/ioemu/iodev/crc32.cc
new file mode 100644
index 0000000000..a20abaaf82
--- /dev/null
+++ b/tools/ioemu/iodev/crc32.cc
@@ -0,0 +1,49 @@
+/////////////////////////////////////////////////////////////////////////
+// $Id: crc32.cc,v 1.4 2001/10/03 13:10:38 bdenney Exp $
+/////////////////////////////////////////////////////////////////////////
+//
+/* CRC-32 calculator
+ * Adapted from http://www.createwindow.org/programming/crc32/
+ */
+
+#include "crc32.h"
+
+CRC_Generator::CRC_Generator() {
+	init();
+}
+
+void CRC_Generator::init(void) {
+  Bit32u POLYNOMIAL = 0x04c11db7;
+  int i;
+
+  for(i = 0; i<0xFF; i++) {
+    int j;
+    crc32_table[i]=reflect(i,8) << 24;
+    for(j=0; j<8; j++)
+      crc32_table[i] = (crc32_table[i]<<1)^(crc32_table[i] & (1<<31) ? POLYNOMIAL : 0);
+    crc32_table[i] = reflect(crc32_table[i], 32);
+  }
+}
+
+Bit32u CRC_Generator::reflect(Bit32u ref, Bit8u ch) {
+  Bit32u value(0);
+  int i;
+
+  for(i=1; i<(ch+1); i++) {
+    if(ref & 1)
+      value |= 1 << (ch-i);
+    ref >>= 1;
+  }
+  return value;
+}
+
+Bit32u CRC_Generator::get_CRC(Bit8u * buf, Bit32u buflen) {
+  Bit32u ulCRC(0xFFFFFFFF);
+  Bit32u len(buflen);
+  Bit8u * buffer=(Bit8u *) buf;
+
+  while(len--)
+    ulCRC=(ulCRC>>8)^crc32_table[(ulCRC & 0xFF)^*buffer++];
+  return ulCRC ^ 0xFFFFFFFF;
+}
+