net: add helper to generate random mac address
Add new function eth_random_enetaddr() to generate a locally administered
ethernet address.
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Joe Hershberger <joe.hershberger@gmail.com>
diff --git a/net/eth.c b/net/eth.c
index d9a6430..d526264 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -70,6 +70,28 @@
return ((skip_state = getenv(enetvar)) != NULL);
}
+#ifdef CONFIG_RANDOM_MACADDR
+void eth_random_enetaddr(uchar *enetaddr)
+{
+ uint32_t rval;
+
+ srand(get_timer(0));
+
+ rval = rand();
+ enetaddr[0] = rval & 0xff;
+ enetaddr[1] = (rval >> 8) & 0xff;
+ enetaddr[2] = (rval >> 16) & 0xff;
+
+ rval = rand();
+ enetaddr[3] = rval & 0xff;
+ enetaddr[4] = (rval >> 8) & 0xff;
+ enetaddr[5] = (rval >> 16) & 0xff;
+
+ /* make sure it's local and unicast */
+ enetaddr[0] = (enetaddr[0] | 0x02) & ~0x01;
+}
+#endif
+
/*
* CPU and board-specific Ethernet initializations. Aliased function
* signals caller to move on