wram analysis

snes/wram/crc.c

@@ -0,0 +1,37 @@
+#include "data.h"
+
+
+word crc_update(char far * data, word size)
+{
+    word i;
+    word j;
+    word crc = 0;
+    for (j = 0; j < size; j++) {
+        crc = crc ^ ((word) data[j] << 8);
+        for (i = 0; i < 8; i++) {
+            if (crc & 0x8000)
+                crc = (crc << 1) ^ 0x1021;
+            else
+                crc <<= 1;
+        }
+    }
+    return crc;
+}
+
+
+word crc_update_mem(unsigned long addr, word size)
+{
+    word i;
+    word j;
+    word crc = 0;
+    for (j = 0; j < size; j++) {
+        crc = crc ^ ((word) * (byte *) (addr + j) << 8);
+        for (i = 0; i < 8; i++) {
+            if (crc & 0x8000)
+                crc = (crc << 1) ^ 0x1021;
+            else
+                crc <<= 1;
+        }
+    }
+    return crc;
+}