Sami Mujawar 0e07733023 ArmPlatformPkg: Timer access for non-secure EL1/0
According to Section 2.3.6 of the "UEFI Specification 2.6 Errata A";
the primary CPU must be configured such that 'Timer access must be
provided to non-secure EL1 and EL0 by setting bits EL1PCTEN and
EL1PCEN in register CNTHCTL_EL2.'

This commit adds this missing set-up to the PrePi and PrePeiCore
modules.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
2017-05-22 15:20:04 +01:00

49 lines
1.8 KiB
ArmAsm

#========================================================================================
# Copyright (c) 2011-2017, 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>
// 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