[boot-wrapper PATCH 2/5] aarch32: simplify _switch_monitor
From: Mark Rutland <mark.rutland@arm.com>
Date: 2021-08-24 13:52:17
Subsystem:
the rest · Maintainer:
Linus Torvalds
If we're lucky enough to have been booted into secure PL1, we can switch to monitor mode with an exception return rather than an SMC call, which avoids the need for boot-time vectors. Note that while all Secure PL1 register state is accessible in Secure SVC mode, we must switch to Monitor mode before we set SCR.NS=1. Signed-off-by: Mark Rutland <mark.rutland@arm.com> --- arch/aarch32/boot.S | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-)
diff --git a/arch/aarch32/boot.S b/arch/aarch32/boot.S
index 82927de..e397cb0 100644
--- a/arch/aarch32/boot.S
+++ b/arch/aarch32/boot.S@@ -37,9 +37,10 @@ ASM_FUNC(_start) b start_no_el3 _switch_monitor: - ldr r0, =boot_vectors - bl setup_vector - smc #0 + adr lr, _monitor + ldr r0, =(PSR_A | PSR_I | PSR_F | PSR_MON) + msr spsr, r0 + movs pc, lr _monitor: /* Move the stack to Monitor mode*/
@@ -102,18 +103,6 @@ ASM_FUNC(jump_kernel) msr spsr_cxf, r4 movs pc, lr - .section .vectors - .align 6 -boot_vectors: - b . - b . - b _monitor - b . - b . - b . - b . - b . - .section .data .align 2 flag_no_el3:
--
2.11.0
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