+inline void
+memcpy_far(u16 d_seg, void *d_far, u16 s_seg, const void *s_far, size_t len)
+{
+ SET_SEG(ES, d_seg);
+ u16 bkup_ds;
+ asm volatile(
+ "movw %%ds, %w0\n"
+ "movw %w4, %%ds\n"
+ "rep movsb (%%si),%%es:(%%di)\n"
+ "movw %w0, %%ds"
+ : "=&r"(bkup_ds), "+c"(len), "+S"(s_far), "+D"(d_far)
+ : "r"(s_seg)
+ : "cc", "memory");
+}
+
+inline void
+memcpy_fl(void *d_fl, const void *s_fl, size_t len)
+{
+ if (MODESEGMENT)
+ memcpy_far(FLATPTR_TO_SEG(d_fl), (void*)FLATPTR_TO_OFFSET(d_fl)
+ , FLATPTR_TO_SEG(s_fl), (void*)FLATPTR_TO_OFFSET(s_fl)
+ , len);
+ else
+ memcpy(d_fl, s_fl, len);
+}
+
+void *
+#undef memcpy
+memcpy(void *d1, const void *s1, size_t len)
+#if MODESEGMENT == 0
+#define memcpy __builtin_memcpy
+#endif
+{
+ SET_SEG(ES, GET_SEG(SS));
+ void *d = d1;
+ if (((u32)d1 | (u32)s1 | len) & 3) {
+ // non-aligned memcpy
+ asm volatile(
+ "rep movsb (%%esi),%%es:(%%edi)"
+ : "+c"(len), "+S"(s1), "+D"(d)
+ : : "cc", "memory");
+ return d1;