commit 262b374df70fdd6b3fe43945d3561e5eddc2a905
Author: Michal Suchanek <hramrach@gmail.com>
Date:   Tue Oct 29 11:40:00 2013 +0100

    Hack to pass ethernet mac address on the commandline.

    Signed-off-by: Michal Suchanek <hramrach@gmail.com>

diff --git a/drivers/net/ethernet/allwinner/sun4i-emac.c b/drivers/net/ethernet/allwinner/sun4i-emac.c
index 50b853a..5b51ed8 100644
--- a/drivers/net/ethernet/allwinner/sun4i-emac.c
+++ b/drivers/net/ethernet/allwinner/sun4i-emac.c
@@ -852,11 +852,30 @@ static int emac_probe(struct platform_device *pdev)
        if (mac_addr)
                memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);

-       /* Check if the MAC address is valid, if not get a random one */
+       /* Check if the MAC address is valid */
        if (!is_valid_ether_addr(ndev->dev_addr)) {
+               const char * ptr;
+               char * ptr_end;
+#define mac_len 6*2+5U
+               char eth[mac_len + 1];
+               int eth_len, mac_byte_counter;
+               ptr = strstr(boot_command_line, "eth=");
+               eth_len = min(mac_len, strlen(ptr));
+               memcpy(eth, ptr+4, eth_len);
+               eth[eth_len]=0;
+               dev_warn(&pdev->dev, "mac address given on kernel commandline: %s\n", eth);
+               ptr_end = eth;
+               for (mac_byte_counter = 0; mac_byte_counter <= 5; mac_byte_counter ++) {
+                       ndev->dev_addr[mac_byte_counter] = simple_strtol(ptr_end, &ptr_end, 16) | simple_strtol(ptr_end, &ptr_end, 16) << 4;
+                       if(*ptr_end == ':' || *ptr_end == '-' || *ptr_end == ' ') ptr_end++;
+               }
+               dev_warn(&pdev->dev, "MAC address %pM is %svalid.\n", ndev->dev_addr,
+                               is_valid_ether_addr(ndev->dev_addr)? "" : "NOT ");
+               if(!is_valid_ether_addr(ndev->dev_addr)){
                eth_hw_addr_random(ndev);
                dev_warn(&pdev->dev, "using random MAC address %pM\n",
                         ndev->dev_addr);
+               }
        }

        db->emacrx_completed_flag = 1;