| From 252cbd36e51414b60ab68306f9c38e358709494d Mon Sep 17 00:00:00 2001 |
| From: Jaxson Han <jaxson.han@arm.com> |
| Date: Tue, 25 May 2021 07:25:00 +0100 |
| Subject: [PATCH] aarch64: Prepare for lower EL booting |
| |
| 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. |
| |
| Upstream-Status: Pending |
| Signed-off-by: Jaxson Han <jaxson.han@arm.com> |
| Reviewed-by: Andre Przywara <andre.przywara@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 5105b41..243198d 100644 |
| --- a/arch/aarch64/boot.S |
| +++ b/arch/aarch64/boot.S |
| @@ -151,7 +151,16 @@ el3_init: |
| mov x0, #ZCR_EL3_LEN_MAX // 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, =COUNTER_FREQ |
| msr cntfrq_el0, x0 |
| |
| @@ -199,7 +208,7 @@ ASM_FUNC(jump_kernel) |
| b.eq 1f |
| br x19 // Keep current EL |
| |
| -1: mov x4, #SPSR_KERNEL |
| +1: ldr w4, spsr_to_elx |
| |
| /* |
| * If bit 0 of the kernel address is set, we're entering in AArch32 |
| @@ -217,3 +226,5 @@ ASM_FUNC(jump_kernel) |
| .align 3 |
| flag_keep_el: |
| .long 0 |
| +spsr_to_elx: |
| + .long 0 |