armv8: fix gd after relocation

Commit 21f4486faa5d ("armv8: update gd after relocate") sets x18
without checking the return value of spl_relocate_stack_gd().

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: York Sun <york.sun@nxp.com>
CC: Kever Yang <kever.yang@rock-chips.com>
CC: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index ccefce0b20a4658d383c61f7981009ca6855cd0f..9cb70552fedad205d0dba215134dbb12324b9906 100644 (file)
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -120,8 +120,9 @@ relocation_return:
 #endif /* !CONFIG_SPL_BUILD */
 #if defined(CONFIG_SPL_BUILD)
        bl      spl_relocate_stack_gd           /* may return NULL */
-       /* set up gd here, outside any C code */
-       mov     x18, x0
+       /* set up gd here, outside any C code, if new stack is returned */
+       cmp     x0, #0
+       csel    x18, x0, x18, ne
        /*
         * Perform 'sp = (x0 != NULL) ? x0 : sp' while working
         * around the constraint that conditional moves can not