audk/ArmPlatformPkg/Sec/AArch64/Helper.S

94 lines
3.1 KiB
ArmAsm

#========================================================================================
# Copyright (c) 2011-2014, ARM Limited. All rights reserved.
#
# This program and the accompanying materials
# are licensed and made available under the terms and conditions of the BSD License
# which accompanies this distribution. The full text of the license may be found at
# http:#opensource.org/licenses/bsd-license.php
#
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#
#=======================================================================================
#include <AsmMacroIoLibV8.h>
#include <Chipset/AArch64.h>
#start of the code section
.text
.align 3
GCC_ASM_EXPORT(SwitchToNSExceptionLevel1)
GCC_ASM_EXPORT(enter_monitor_mode)
GCC_ASM_EXPORT(return_from_exception)
GCC_ASM_EXPORT(copy_cpsr_into_spsr)
GCC_ASM_EXPORT(set_non_secure_mode)
// Switch from EL3 to NS-EL1
ASM_PFX(SwitchToNSExceptionLevel1):
// Now setup our EL1. Controlled by EL2 config on Model
mrs x0, hcr_el2 // Read EL2 Hypervisor configuration Register
orr x0, x0, #(1 << 31) // Set EL1 to be 64bit
// Send all interrupts to their respective Exception levels for EL2
and x0, x0, #~(ARM_HCR_FMO | ARM_HCR_IMO | ARM_HCR_AMO) // Disable virtual FIQ, IRQ, SError and Abort
msr hcr_el2, x0 // Write back our settings
msr cptr_el2, xzr // Disable copro traps to EL2
msr sctlr_el2, xzr
// Enable architected timer access
mrs x0, cnthctl_el2
orr x0, x0, #3 // Enable EL1 access to timers
msr cnthctl_el2, x0
mrs x0, cntkctl_el1
orr x0, x0, #3 // EL0 access to counters
msr cntkctl_el1, x0
// Set ID regs
mrs x0, midr_el1
mrs x1, mpidr_el1
msr vpidr_el2, x0
msr vmpidr_el2, x1
ret
// EL3 on AArch64 is Secure/monitor so this funtion is reduced vs ARMv7
// we don't need a mode switch, just setup the Arguments and jump.
// x0: Monitor World EntryPoint
// x1: MpId
// x2: SecBootMode
// x3: Secure Monitor mode stack
ASM_PFX(enter_monitor_mode):
mov x4, x0 // Swap EntryPoint and MpId registers
mov x0, x1
mov x1, x2
mov x2, x3
br x4
// Put the address in correct ELR_ELx and do a eret.
// We may need to do some config before we change to another Mode.
ASM_PFX(return_from_exception):
msr elr_el3, x0
eret
// For AArch64 we need to construct the spsr we want from individual bits and pieces.
ASM_PFX(copy_cpsr_into_spsr):
mrs x0, CurrentEl // Get the current exception level we are running at.
mrs x1, SPSel // Which Stack are we using
orr x0, x0, x1
mrs x1, daif // Which interrupts are enabled
orr x0, x0, x1
msr spsr_el3, x0 // Write to spsr
ret
// Get this from platform file.
ASM_PFX(set_non_secure_mode):
msr spsr_el3, x0
ret
ASM_FUNCTION_REMOVE_IF_UNREFERENCED