sunxi: armv8: FEL: save and restore SP_IRQ

Thanks for Jernej's JTAG debugging effort, it turns out that the BROM
expects SP_IRQ to be saved and restored, when we want to enter back into
FEL after the SPL's AArch64 stint.
Save and restore SP_IRQ as part of the FEL state handling. The banked
MRS/MSR access to SP_IRQ, without actually being in IRQ mode, was
introduced with the ARMv7 virtualisation extensions. The Arm Cortex-A8
cores used in the A10/A13s or older F1C100s SoCs would not support that,
but this code here is purely in the ARMv8/AArch64 code path, so it's
safe to use unconditionally.

Reported-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
This commit is contained in:
Andre Przywara
2025-02-10 00:25:29 +00:00
committed by Tom Rini
parent 5a9014a8ea
commit 1d26da5a6a
4 changed files with 13 additions and 6 deletions

View File

@@ -74,15 +74,17 @@ back_in_32:
.word 0xf57ff06f // isb
.word 0xe590d000 // ldr sp, [r0]
.word 0xe590e004 // ldr lr, [r0, #4]
.word 0xe5901014 // ldr r1, [r0, #20]
.word 0xe121f301 // msr SP_irq, r1
.word 0xe5901010 // ldr r1, [r0, #16]
.word 0xee0c1f10 // mcr 15, 0, r1, cr12, cr0, {0} ; VBAR
.word 0xe590100c // ldr r1, [r0, #12]
.word 0xee011f10 // mcr 15, 0, r1, cr1, cr0, {0} ; SCTLR
.word 0xf57ff06f // isb
#ifdef CONFIG_MACH_SUN55I_A523
.word 0xe5901014 // ldr r1, [r0, #20]
.word 0xee041f16 // mcr 15, 0, r1, cr4, cr6, {0}; ICC_PMR
.word 0xe5901018 // ldr r1, [r0, #24]
.word 0xee041f16 // mcr 15, 0, r1, cr4, cr6, {0}; ICC_PMR
.word 0xe590101c // ldr r1, [r0, #28]
.word 0xee0c1ffc // mcr 15, 0, r1, cr12, cr12, {7}; ICC_IGRPEN1
#endif

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@@ -26,6 +26,8 @@
.word 0xe580e004 // str lr, [r0, #4]
.word 0xe10fe000 // mrs lr, CPSR
.word 0xe580e008 // str lr, [r0, #8]
.word 0xe101e300 // mrs lr, SP_irq
.word 0xe580e014 // str lr, [r0, #20]
.word 0xee11ef10 // mrc 15, 0, lr, cr1, cr0, {0}
.word 0xe580e00c // str lr, [r0, #12]
.word 0xee1cef10 // mrc 15, 0, lr, cr12, cr0, {0}
@@ -35,9 +37,9 @@
.word 0xe31e0001 // tst lr, #1
.word 0x0a000003 // beq cc <start32+0x48>
.word 0xee14ef16 // mrc 15, 0, lr, cr4, cr6, {0}
.word 0xe580e014 // str lr, [r0, #20]
.word 0xee1ceffc // mrc 15, 0, lr, cr12, cr12, {7}
.word 0xe580e018 // str lr, [r0, #24]
.word 0xee1ceffc // mrc 15, 0, lr, cr12, cr12, {7}
.word 0xe580e01c // str lr, [r0, #28]
#endif
.word 0xe59f1034 // ldr r1, [pc, #52] ; RVBAR_ADDRESS
.word 0xe59f0034 // ldr r0, [pc, #52] ; SUNXI_SRAMC_BASE

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@@ -35,6 +35,7 @@ struct fel_stash {
uint32_t cpsr;
uint32_t sctlr;
uint32_t vbar;
uint32_t sp_irq;
uint32_t icc_pmr;
uint32_t icc_igrpen1;
};

View File

@@ -49,6 +49,8 @@ start32:
str lr, [r0, #4]
mrs lr, CPSR
str lr, [r0, #8]
mrs lr, SP_irq
str lr, [r0, #20]
mrc p15, 0, lr, cr1, cr0, 0 // SCTLR
str lr, [r0, #12]
mrc p15, 0, lr, cr12, cr0, 0 // VBAR
@@ -58,9 +60,9 @@ start32:
tst lr, #1
beq 1f
mrc p15, 0, lr, c4, c6, 0 // ICC_PMR
str lr, [r0, #20]
mrc p15, 0, lr, c12, c12, 7 // ICC_IGRPEN1
str lr, [r0, #24]
mrc p15, 0, lr, c12, c12, 7 // ICC_IGRPEN1
str lr, [r0, #28]
1:
//#endif