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https://github.com/ARM-software/arm-trusted-firmware.git
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a806dad58c
There are many instances in ARM Trusted Firmware where control is transferred to functions from which return isn't expected. Such jumps are made using 'bl' instruction to provide the callee with the location from which it was jumped to. Additionally, debuggers infer the caller by examining where 'lr' register points to. If a 'bl' of the nature described above falls at the end of an assembly function, 'lr' will be left pointing to a location outside of the function range. This misleads the debugger back trace. This patch defines a 'no_ret' macro to be used when jumping to functions from which return isn't expected. The macro ensures to use 'bl' instruction for the jump, and also, for debug builds, places a 'nop' instruction immediately thereafter (unless instructed otherwise) so as to leave 'lr' pointing within the function range. Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0 Co-authored-by: Douglas Raillard <douglas.raillard@arm.com> Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
136 lines
4.3 KiB
ArmAsm
136 lines
4.3 KiB
ArmAsm
/*
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* Copyright (c) 2013-2016, 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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.globl bl2_entrypoint
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func bl2_entrypoint
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/*---------------------------------------------
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* Save from x1 the extents of the tzram
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* available to BL2 for future use.
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* x0 is not currently used.
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* ---------------------------------------------
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*/
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mov x20, x1
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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 x0, early_exceptions
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msr vbar_el1, x0
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isb
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/* ---------------------------------------------
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* Enable the SError interrupt now that the
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* exception vectors have been setup.
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* ---------------------------------------------
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*/
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msr daifclr, #DAIF_ABT_BIT
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/* ---------------------------------------------
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* Enable the instruction cache, stack pointer
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* and data access alignment checks
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* ---------------------------------------------
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*/
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mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
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mrs x0, sctlr_el1
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orr x0, x0, x1
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msr sctlr_el1, x0
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isb
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/* ---------------------------------------------
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* Invalidate the RW memory used by the BL2
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* image. This includes the data and NOBITS
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* sections. This is done to safeguard against
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* possible corruption of this memory by dirty
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* cache lines in a system cache as a result of
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* use by an earlier boot loader stage.
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* ---------------------------------------------
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*/
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adr x0, __RW_START__
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adr x1, __RW_END__
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sub x1, x1, x0
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bl inv_dcache_range
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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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#if USE_COHERENT_MEM
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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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#endif
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/* --------------------------------------------
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* Allocate a stack whose memory will be marked
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* as Normal-IS-WBWA when the MMU is enabled.
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* There is no risk of reading stale stack
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* memory after enabling the MMU as only the
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* primary cpu is running at the moment.
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* --------------------------------------------
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*/
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bl plat_set_my_stack
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/* ---------------------------------------------
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* Perform early platform setup & platform
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* specific early arch. setup e.g. mmu setup
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* ---------------------------------------------
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*/
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mov x0, x20
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bl bl2_early_platform_setup
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bl bl2_plat_arch_setup
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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 bl2_main
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/* ---------------------------------------------
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* Should never reach this point.
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* ---------------------------------------------
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*/
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no_ret plat_panic_handler
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endfunc bl2_entrypoint
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