[U-Boot] [PATCH 1/2] ARM: Add save_boot_params for ARMv8

[Stephen Warren]

From: Stephen Warren <swarren at nvidia.com>

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 at nvidia.com>
---
 arch/arm/cpu/armv8/start.S | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index dfce46920668..f77fa44ad6c3 100644
--- 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
@@ -288,3 +293,7 @@ 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)
-- 
2.9.2