diff options
| author | Mark Kettenis <kettenis@openbsd.org> | 2021-02-10 22:14:55 +0300 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-07-09 18:36:12 +0300 |
| commit | bfb798461af42ac628e22cbf5a0576fa156e8787 (patch) | |
| tree | 01b70bc25a91cdc1544e681ea0680d93352f1b16 /arch/arm/cpu | |
| parent | fd075f77ca56ffb07e0b1979f0cb47fc8831600f (diff) | |
| download | u-boot-bfb798461af42ac628e22cbf5a0576fa156e8787.tar.xz | |
armv8: Handle EL2 Host mode
On implementations that support VHE, the layout of the CPTR_EL2
register depends on whether HCR_EL2.E2H is set. If the bit is
set, CPTR_EL2 uses the same layout as CPACR_EL1 and can in fact
be accessed through that register. In that case, jump to the
EL1 code to enable access to the FP/SIMD registers. This allows
U-Boot to run on systems that pass control to U-Boot in EL2 with
EL2 Host mode enabled such as machines using Apple's M1 SoC.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm/cpu')
| -rw-r--r-- | arch/arm/cpu/armv8/start.S | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S index 662449156b..9e9c6140cd 100644 --- a/arch/arm/cpu/armv8/start.S +++ b/arch/arm/cpu/armv8/start.S @@ -132,11 +132,13 @@ pie_fixup_done: msr cntfrq_el0, x0 /* Initialize CNTFRQ */ #endif b 0f -2: set_vbar vbar_el2, x0 +2: mrs x1, hcr_el2 + tbnz x1, #34, 1f /* HCR_EL2.E2H */ + set_vbar vbar_el2, x0 mov x0, #0x33ff msr cptr_el2, x0 /* Enable FP/SIMD */ b 0f -1: set_vbar vbar_el1, x0 +1: set_vbar vbar_el1, x0 mov x0, #3 << 20 msr cpacr_el1, x0 /* Enable FP/SIMD */ 0: |