audk/ArmPlatformPkg/PrePeiCore/AArch64/Helper.S

43 lines
1.4 KiB
ArmAsm

#========================================================================================
# Copyright (c) 2011-2017, ARM Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
#=======================================================================================
#include <AsmMacroIoLibV8.h>
#include <Chipset/AArch64.h>
// Setup EL1 while in EL1
ASM_FUNC(SetupExceptionLevel1)
mov x5, x30 // Save LR
mov x0, #CPACR_CP_FULL_ACCESS
bl ASM_PFX(ArmWriteCpacr) // Disable copro traps to EL1
ret x5
// Setup EL2 while in EL2
ASM_FUNC(SetupExceptionLevel2)
msr sctlr_el2, xzr
mrs x0, hcr_el2 // Read EL2 Hypervisor configuration Register
// Send all interrupts to their respective Exception levels for EL2
orr x0, x0, #(1 << 3) // Enable EL2 FIQ
orr x0, x0, #(1 << 4) // Enable EL2 IRQ
orr x0, x0, #(1 << 5) // Enable EL2 SError and Abort
msr hcr_el2, x0 // Write back our settings
msr cptr_el2, xzr // Disable copro traps to EL2
// Enable Timer access for non-secure EL1 and EL0
// The cnthctl_el2 register bits are architecturally
// UNKNOWN on reset.
// Disable event stream as it is not in use at this stage
mov x0, #(CNTHCTL_EL2_EL1PCTEN | CNTHCTL_EL2_EL1PCEN)
msr cnthctl_el2, x0
ret
ASM_FUNCTION_REMOVE_IF_UNREFERENCED