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https://github.com/ARM-software/arm-trusted-firmware.git
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8cec598ba3
The current code does not always use data and instruction barriers as required by the architecture and frequently uses barriers excessively due to their inclusion in all of the write_*() helper functions. Barriers should be used explicitly in assembler or C code when modifying processor state that requires the barriers in order to enable review of correctness of the code. This patch removes the barriers from the helper functions and introduces them as necessary elsewhere in the code. PORTING NOTE: check any port of Trusted Firmware for use of system register helper functions for reliance on the previous barrier behaviour and add explicit barriers as necessary. Fixes ARM-software/tf-issues#92 Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf
171 lines
5.5 KiB
ArmAsm
171 lines
5.5 KiB
ArmAsm
/*
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* Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of ARM nor the names of its contributors may be used
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* to endorse or promote products derived from this software without specific
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* prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <arch.h>
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#include <asm_macros.S>
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#include <bl_common.h>
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#include <cm_macros.S>
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.globl bl31_entrypoint
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/* -----------------------------------------------------
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* bl31_entrypoint() is the cold boot entrypoint,
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* executed only by the primary cpu.
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* -----------------------------------------------------
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*/
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func bl31_entrypoint
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/* ---------------------------------------------
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* BL2 has populated x0 with the opcode
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* indicating BL31 should be run, x3 with
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* a pointer to a 'bl31_args' structure & x4
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* with any other optional information
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* ---------------------------------------------
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*/
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/* ---------------------------------------------
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* Set the exception vector to something sane.
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* ---------------------------------------------
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*/
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adr x1, early_exceptions
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msr vbar_el3, x1
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/* ---------------------------------------------------------------------
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* The initial state of the Architectural feature trap register
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* (CPTR_EL3) is unknown and it must be set to a known state. All
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* feature traps are disabled. Some bits in this register are marked as
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* Reserved and should not be modified.
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*
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* CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1
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* or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2.
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* CPTR_EL3.TTA: This causes access to the Trace functionality to trap
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* to EL3 when executed from EL0, EL1, EL2, or EL3. If system register
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* access to trace functionality is not supported, this bit is RES0.
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* CPTR_EL3.TFP: This causes instructions that access the registers
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* associated with Floating Point and Advanced SIMD execution to trap
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* to EL3 when executed from any exception level, unless trapped to EL1
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* or EL2.
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* ---------------------------------------------------------------------
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*/
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mrs x1, cptr_el3
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bic w1, w1, #TCPAC_BIT
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bic w1, w1, #TTA_BIT
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bic w1, w1, #TFP_BIT
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msr cptr_el3, x1
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/* ---------------------------------------------
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* Enable the instruction cache.
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* ---------------------------------------------
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*/
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mrs x1, sctlr_el3
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orr x1, x1, #SCTLR_I_BIT
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msr sctlr_el3, x1
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isb
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/* ---------------------------------------------
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* Check the opcodes out of paranoia.
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* ---------------------------------------------
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*/
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mov x19, #RUN_IMAGE
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cmp x0, x19
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b.ne _panic
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mov x20, x3
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mov x21, x4
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/* ---------------------------------------------
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* This is BL31 which is expected to be executed
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* only by the primary cpu (at least for now).
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* So, make sure no secondary has lost its way.
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* ---------------------------------------------
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*/
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bl read_mpidr
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mov x19, x0
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bl platform_is_primary_cpu
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cbz x0, _panic
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/* ---------------------------------------------
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* Zero out NOBITS sections. There are 2 of them:
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* - the .bss section;
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* - the coherent memory section.
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* ---------------------------------------------
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*/
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ldr x0, =__BSS_START__
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ldr x1, =__BSS_SIZE__
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bl zeromem16
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ldr x0, =__COHERENT_RAM_START__
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ldr x1, =__COHERENT_RAM_UNALIGNED_SIZE__
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bl zeromem16
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/* ---------------------------------------------
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* Use SP_EL0 for the C runtime stack.
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* ---------------------------------------------
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*/
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msr spsel, #0
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/* --------------------------------------------
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* Give ourselves a small coherent stack to
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* ease the pain of initializing the MMU
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* --------------------------------------------
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*/
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mov x0, x19
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bl platform_set_coherent_stack
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/* ---------------------------------------------
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* Perform platform specific early arch. setup
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* ---------------------------------------------
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*/
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mov x0, x20
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mov x1, x21
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bl bl31_early_platform_setup
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bl bl31_plat_arch_setup
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/* ---------------------------------------------
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* Give ourselves a stack allocated in Normal
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* -IS-WBWA memory
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* ---------------------------------------------
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*/
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mov x0, x19
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bl platform_set_stack
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/* ---------------------------------------------
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* Jump to main function.
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* ---------------------------------------------
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*/
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bl bl31_main
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zero_callee_saved_regs
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b el3_exit
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_panic:
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wfi
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b _panic
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