[ecm] Use ACPI-provided system-specific MAC address if present

Use the "system MAC address" provided within the DSDT/SSDT if such an
address is available and has not already been assigned to a network
device.

Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/drivers/net/ecm.c b/src/drivers/net/ecm.c
index f531b04f8b7f9f31640d8f0081e45492232549c3..826b3b16d28ac199b8c229b648f2cce9039e5e85 100644 (file)
--- a/src/drivers/net/ecm.c
+++ b/src/drivers/net/ecm.c
@@ -30,6 +30,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/if_ether.h>
 #include <ipxe/base16.h>
 #include <ipxe/profile.h>
+#include <ipxe/acpimac.h>
 #include <ipxe/usb.h>
 #include "ecm.h"
 
@@ -93,6 +94,14 @@ int ecm_fetch_mac ( struct usb_function *func,
        int len;
        int rc;
 
+       /* Use system-specific MAC address, if present and not already used */
+       if ( ( ( rc = acpi_mac ( hw_addr ) ) == 0 ) &&
+            ! find_netdev_by_ll_addr ( &ethernet_protocol, hw_addr ) ) {
+               DBGC ( usb, "USB %s using system-specific MAC %s\n",
+                      func->name, eth_ntoa ( hw_addr ) );
+               return 0;
+       }
+
        /* Fetch MAC address string */
        len = usb_get_string_descriptor ( usb, desc->mac, 0, buf,
                                          sizeof ( buf ) );