diff options
Diffstat (limited to 'payloads/libpayload/arch/arm64/cpu.S')
| -rw-r--r-- | payloads/libpayload/arch/arm64/cpu.S | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/payloads/libpayload/arch/arm64/cpu.S b/payloads/libpayload/arch/arm64/cpu.S index d80f73c112..70a1044b02 100644 --- a/payloads/libpayload/arch/arm64/cpu.S +++ b/payloads/libpayload/arch/arm64/cpu.S @@ -29,6 +29,7 @@ */ #include <arch/asm.h> +#include <arch/lib_helpers.h> .macro dcache_apply_all crm dsb sy @@ -96,3 +97,17 @@ ENDPROC(dcache_clean_all) ENTRY(dcache_clean_invalidate_all) dcache_apply_all crm=cisw ENDPROC(dcache_clean_invalidate_all) + +/* This must be implemented in assembly to ensure there are no accesses to + memory (e.g. the stack) in between disabling and flushing the cache. */ +ENTRY(mmu_disable) + str x30, [sp, #-0x8] + mrs x0, sctlr_el2 + mov x1, #~(SCTLR_C | SCTLR_M) + and x0, x0, x1 + msr sctlr_el2, x0 + isb + bl dcache_clean_invalidate_all + ldr x30, [sp, #-0x8] + ret +ENDPROC(mmu_disable) |