more bpmpfw shenanigans

Source/hoc-clk/bpmpfw/source/libc/src/fslc_memcpy.c

@@ -0,0 +1,40 @@
+#include "fslc_string.h"
+#include <stdint.h>
+
+void *fslc_memcpy(void *dest, const void *src, size_t len)
+{
+    /* Copy byte-by-byte up to word-aligned.
+     *
+     * There's a possibility, that src and dest have different offsets
+     * to word boundary and can not both be used efficiently.
+     *
+     * In this case we use align to dest argument, because it then can be
+     * written in one operation, instead of read-modify-write of 2 words.
+     *
+     * Most of the time both parameters should be word-aligned, however.
+     */
+    unsigned char *b_src = (unsigned char *)src;
+    unsigned char *b_dst = (unsigned char *)dest;
+    for (;((uintptr_t)b_dst & (sizeof(unsigned long)-1)) && len > 0; b_src++, b_dst++, len--)
+    {
+        *b_dst = *b_src;
+    }
+
+    /* Then all word-aligned */
+    unsigned long *w_src  = (unsigned long*)b_src;
+    unsigned long *w_dst = (unsigned long*)b_dst;
+    for (;len >= sizeof(unsigned long); w_src++, w_dst++, len -= sizeof(unsigned long))
+    {
+        *w_dst = *w_src;
+    }
+
+    /* And byte-by-byte the rest */
+    b_src  = (unsigned char *)w_src;
+    b_dst = (unsigned char *)w_dst;
+    for (; len > 0; b_src++, b_dst++, len--)
+    {
+        *b_dst = *b_src;
+    }
+
+    return dest;
+}