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#========================================================================================
# Copyright (c) 2011-2013, 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
ASM_GLOBAL ASM_PFX(SetupExceptionLevel3)
ASM_GLOBAL ASM_PFX(SwitchToNSExceptionLevel1)
ASM_GLOBAL ASM_PFX(enter_monitor_mode)
ASM_GLOBAL ASM_PFX(return_from_exception)
ASM_GLOBAL ASM_PFX(copy_cpsr_into_spsr)
ASM_GLOBAL ASM_PFX(set_non_secure_mode)
ASM_PFX(SetupExceptionLevel3):
mrs x0, scr_el3 // Read EL3 Secure Configuration Register
orr x0, x0, #1 // EL0 an EL1 cannot access secure memory
// Send all interrupts to their respective Exception levels for EL3
bic x0, x0, #(1 << 1) // IRQ
bic x0, x0, #(1 << 2) // FIQ
bic x0, x0, #(1 << 3) // Serror and Abort
orr x0, x0, #(1 << 8) // Enable HVC
orr x0, x0, #(1 << 10) // Make next level down 64Bit. This is EL2 in the case of the Model.
// We need a nice way to detect this.
msr scr_el3, x0 // Write back our settings
msr cptr_el3, xzr // Disable copro traps to EL3
// Check for the primary CPU to avoid a race on the distributor registers.
mrs x0, mpidr_el1
tst x0, #15
b.ne 1f // secondary CPU
LoadConstantToReg (FixedPcdGet32(PcdGicInterruptInterfaceBase), x1)
mov w0, #3 // EnableGrp0 | EnableGrp1
str w0, [x1]
1: LoadConstantToReg (FixedPcdGet32(PcdGicDistributorBase), x1)
add x1, x1, #0x80
mov w0, #~0 // Grp1 interrupts
str w0, [x1], #4
b.ne 2f // Only local interrupts for secondary CPUs
str w0, [x1], #4
str w0, [x1], #4
2: LoadConstantToReg (FixedPcdGet32(PcdGicInterruptInterfaceBase), x1)
ldr w0, [x1]
mov w0, #3 // EnableGrp0 | EnableGrp1
str w0, [x1]
mov w0, #1 << 7 // allow NS access to GICC_PMR
str w0, [x1, #4] // GICC_PMR
ret
// 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
bic x0, x0, #(1 << 3) // Disable virtual FIQ
bic x0, x0, #(1 << 4) // Disable virtual IRQ
bic x0, x0, #(1 << 5) // Disable virtual 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
mrs x7, spsr_el3
ands w7, w7, #0xC
cmp w7, #0xC // EL3?
b.eq 3f
bl ASM_PFX(SetupExceptionLevel3)
cmp w7, #0x8 // EL2?
b.eq 2f
cmp w7, #0x4 // EL1?
b.eq 1f
b dead // We should never get here.
1: bl ASM_PFX(SwitchToNSExceptionLevel1)
2: // EL2: No more setup required.
3: // EL3: Not sure why we would do this.
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
dead:
b dead
ASM_FUNCTION_REMOVE_IF_UNREFERENCED
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