[boot-wrapper PATCH v2 5/8] aarch64: Prepare for lower EL booting

[Jaxson Han]

Save SPSR_KERNEL into spsr_to_elx during el3_init.
The jump_kernel will load spsr_to_elx into spsr_el3.

This change will make it easier to control whether drop to lower EL
before jumping to the kernel.

Signed-off-by: Jaxson Han <jaxson.han at arm.com>
---
 arch/aarch64/boot.S | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
index b8f9e4e..5600859 100644
--- a/arch/aarch64/boot.S
+++ b/arch/aarch64/boot.S
@@ -118,7 +118,16 @@ el3_init:
 	mov	x0, #ZCR_EL3_LEN_MASK		// SVE: Enable full vector len
 	msr	ZCR_EL3, x0			// for EL2.
 
-1:
+	/*
+	 * Save SPSR_KERNEL into spsr_to_elx.
+	 * The jump_kernel will load spsr_to_elx into spsr_el3
+	 */
+1:	mov	w0, #SPSR_KERNEL
+	ldr	x1, =spsr_to_elx
+	str	w0, [x1]
+	b	el_max_init
+
+el_max_init:
 	ldr	x0, =CNTFRQ
 	msr	cntfrq_el0, x0
 
@@ -166,7 +175,7 @@ jump_kernel:
 	b.eq	1f
 	br	x19			// Keep current EL
 
-1:	ldr	w4, #SPSR_KERNEL
+1:	ldr	w4, spsr_to_elx
 
 	/*
 	 * If bit 0 of the kernel address is set, we're entering in AArch32
@@ -184,3 +193,5 @@ jump_kernel:
 	.align 3
 flag_keep_el:
 	.long 0
+spsr_to_elx:
+	.long 0
-- 
2.25.1