ARM: Add save_boot_params for ARMv8

Implement a hook to allow boards to save boot-time CPU state for later
use. When U-Boot is chain-loaded by another bootloader, CPU registers may
contain useful information such as system configuration information. This
feature mirrors the equivalent ARMv7 feature.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index 67edf94..19c771d 100644 (file)
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -53,6 +53,11 @@ _bss_end_ofs:
        .quad   __bss_end - _start
 
 reset:
+       /* Allow the board to save important registers */
+       b       save_boot_params
+.globl save_boot_params_ret
+save_boot_params_ret:
+
 #ifdef CONFIG_SYS_RESET_SCTRL
        bl reset_sctrl
 #endif
@@ -282,3 +287,7 @@ ENTRY(c_runtime_cpu_setup)
 
        ret
 ENDPROC(c_runtime_cpu_setup)
+
+WEAK(save_boot_params)
+       b       save_boot_params_ret    /* back to my caller */
+ENDPROC(save_boot_params)