generic: fix appended dtb support

Appended DTB support is mostly intended to be used on legacy systems,
but it is a valid feature that can be enabled for generic platform,
which currently doesn't support it - if selected, the appended DTB will
be ignored by the platform startup code.

During kernel startup, the appended DTB's location is stored in
fw_passed_dtb if the init code finds what appears to be a valid DTB.
Otherwise (if a0 == -2), a1 is stored in fw_passed_dtb, so either way it
will always point to either a user-passed DTB or built-in DTB.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@fungible.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

diff --git a/arch/mips/generic/init.c b/arch/mips/generic/init.c
index a106f81..a84475f 100644 (file)
--- a/arch/mips/generic/init.c
+++ b/arch/mips/generic/init.c
@@ -43,14 +43,14 @@ void __init *plat_get_fdt(void)
                /* Already set up */
                return (void *)fdt;
 
-       if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
+       if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_passed_dtb)) {
                /*
                 * We booted using the UHI boot protocol, so we have been
                 * provided with the appropriate device tree for the board.
                 * Make use of it & search for any machine struct based upon
                 * the root compatible string.
                 */
-               fdt = (void *)fw_arg1;
+               fdt = (void *)fw_passed_dtb;
 
                for_each_mips_machine(check_mach) {
                        match = mips_machine_is_compatible(check_mach, fdt);