ArmPlatformPkg/PrePeiCore/AArch64/Helper.S

   1 #========================================================================================
   2 #  Copyright (c) 2011-2013, ARM Limited. All rights reserved.
   3 #
   4 #  This program and the accompanying materials
   5 #  are licensed and made available under the terms and conditions of the BSD License
   6 #  which accompanies this distribution.  The full text of the license may be found at
   7 #  http:#opensource.org/licenses/bsd-license.php
   8 #
   9 #  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 #  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 #
  12 #=======================================================================================
  13
  14 #include <AsmMacroIoLibV8.h>
  15 #include <Chipset/AArch64.h>
  16
  17 #start of the code section
  18 .text
  19 .align 3
  20
  21 GCC_ASM_EXPORT(SetupExceptionLevel1)
  22 GCC_ASM_EXPORT(SetupExceptionLevel2)
  23
  24 // Setup EL1 while in EL1
  25 ASM_PFX(SetupExceptionLevel1):
  26    mov  x5, x30                   // Save LR
  27
  28    mov  x0, #CPACR_CP_FULL_ACCESS
  29    bl   ASM_PFX(ArmWriteCpacr)    // Disable copro traps to EL1
  30
  31    ret  x5
  32
  33 // Setup EL2 while in EL2
  34 ASM_PFX(SetupExceptionLevel2):
  35    msr     sctlr_el2, xzr
  36    mrs     x0, hcr_el2            // Read EL2 Hypervisor configuration Register
  37
  38    // Send all interrupts to their respective Exception levels for EL2
  39    orr     x0, x0, #(1 << 3)      // Enable EL2 FIQ
  40    orr     x0, x0, #(1 << 4)      // Enable EL2 IRQ
  41    orr     x0, x0, #(1 << 5)      // Enable EL2 SError and Abort
  42    msr     hcr_el2, x0            // Write back our settings
  43
  44    msr     cptr_el2, xzr          // Disable copro traps to EL2
  45
  46    ret
  47
  48 ASM_FUNCTION_REMOVE_IF_UNREFERENCED