arm-trusted-firmware/include/common/aarch32/el3_common_macros.S
Jeenu Viswambharan a806dad58c Define and use no_ret macro where no return is expected
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>
2016-12-05 14:55:35 +00:00

286 lines
9.6 KiB
ArmAsm

/*
* Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __EL3_COMMON_MACROS_S__
#define __EL3_COMMON_MACROS_S__
#include <arch.h>
#include <asm_macros.S>
#include <assert_macros.S>
/*
* Helper macro to initialise EL3 registers we care about.
*/
.macro el3_arch_init_common _exception_vectors
/* ---------------------------------------------------------------------
* Enable the instruction cache and alignment checks
* ---------------------------------------------------------------------
*/
ldr r1, =(SCTLR_RES1 | SCTLR_I_BIT | SCTLR_A_BIT)
ldcopr r0, SCTLR
orr r0, r0, r1
stcopr r0, SCTLR
isb
/* ---------------------------------------------------------------------
* Set the exception vectors (VBAR/MVBAR).
* ---------------------------------------------------------------------
*/
ldr r0, =\_exception_vectors
stcopr r0, VBAR
stcopr r0, MVBAR
isb
/* -----------------------------------------------------
* Enable the SIF bit to disable instruction fetches
* from Non-secure memory.
* -----------------------------------------------------
*/
ldcopr r0, SCR
orr r0, r0, #SCR_SIF_BIT
stcopr r0, SCR
/* -----------------------------------------------------------------
* Reset those registers that may have architecturally unknown reset
* values
* -----------------------------------------------------------------
*/
mov r0, #0
stcopr r0, SDCR
/* -----------------------------------------------------
* Enable the Asynchronous data abort now that the
* exception vectors have been setup.
* -----------------------------------------------------
*/
cpsie a
isb
/* Enable access to Advanced SIMD registers */
ldcopr r0, NSACR
bic r0, r0, #NSASEDIS_BIT
bic r0, r0, #NSTRCDIS_BIT
orr r0, r0, #(NASCR_CP10_BIT | NASCR_CP11_BIT)
stcopr r0, NSACR
isb
/*
* Enable access to Advanced SIMD, Floating point and to the Trace
* functionality as well.
*/
ldcopr r0, CPACR
bic r0, r0, #ASEDIS_BIT
bic r0, r0, #TRCDIS_BIT
orr r0, r0, #CPACR_ENABLE_FP_ACCESS
stcopr r0, CPACR
isb
vmrs r0, FPEXC
orr r0, r0, #FPEXC_EN_BIT
vmsr FPEXC, r0
isb
.endm
/* -----------------------------------------------------------------------------
* This is the super set of actions that need to be performed during a cold boot
* or a warm boot in EL3. This code is shared by BL1 and BL32 (SP_MIN).
*
* This macro will always perform reset handling, architectural initialisations
* and stack setup. The rest of the actions are optional because they might not
* be needed, depending on the context in which this macro is called. This is
* why this macro is parameterised ; each parameter allows to enable/disable
* some actions.
*
* _set_endian:
* Whether the macro needs to configure the endianness of data accesses.
*
* _warm_boot_mailbox:
* Whether the macro needs to detect the type of boot (cold/warm). The
* detection is based on the platform entrypoint address : if it is zero
* then it is a cold boot, otherwise it is a warm boot. In the latter case,
* this macro jumps on the platform entrypoint address.
*
* _secondary_cold_boot:
* Whether the macro needs to identify the CPU that is calling it: primary
* CPU or secondary CPU. The primary CPU will be allowed to carry on with
* the platform initialisations, while the secondaries will be put in a
* platform-specific state in the meantime.
*
* If the caller knows this macro will only be called by the primary CPU
* then this parameter can be defined to 0 to skip this step.
*
* _init_memory:
* Whether the macro needs to initialise the memory.
*
* _init_c_runtime:
* Whether the macro needs to initialise the C runtime environment.
*
* _exception_vectors:
* Address of the exception vectors to program in the VBAR_EL3 register.
* -----------------------------------------------------------------------------
*/
.macro el3_entrypoint_common \
_set_endian, _warm_boot_mailbox, _secondary_cold_boot, \
_init_memory, _init_c_runtime, _exception_vectors
/* Make sure we are in Secure Mode */
#if ASM_ASSERTION
ldcopr r0, SCR
tst r0, #SCR_NS_BIT
ASM_ASSERT(eq)
#endif
.if \_set_endian
/* -------------------------------------------------------------
* Set the CPU endianness before doing anything that might
* involve memory reads or writes.
* -------------------------------------------------------------
*/
ldcopr r0, SCTLR
bic r0, r0, #SCTLR_EE_BIT
stcopr r0, SCTLR
isb
.endif /* _set_endian */
/* Switch to monitor mode */
cps #MODE32_mon
isb
.if \_warm_boot_mailbox
/* -------------------------------------------------------------
* This code will be executed for both warm and cold resets.
* Now is the time to distinguish between the two.
* Query the platform entrypoint address and if it is not zero
* then it means it is a warm boot so jump to this address.
* -------------------------------------------------------------
*/
bl plat_get_my_entrypoint
cmp r0, #0
bxne r0
.endif /* _warm_boot_mailbox */
/* ---------------------------------------------------------------------
* It is a cold boot.
* Perform any processor specific actions upon reset e.g. cache, TLB
* invalidations etc.
* ---------------------------------------------------------------------
*/
bl reset_handler
el3_arch_init_common \_exception_vectors
.if \_secondary_cold_boot
/* -------------------------------------------------------------
* Check if this is a primary or secondary CPU cold boot.
* The primary CPU will set up the platform while the
* secondaries are placed in a platform-specific state until the
* primary CPU performs the necessary actions to bring them out
* of that state and allows entry into the OS.
* -------------------------------------------------------------
*/
bl plat_is_my_cpu_primary
cmp r0, #0
bne do_primary_cold_boot
/* This is a cold boot on a secondary CPU */
bl plat_secondary_cold_boot_setup
/* plat_secondary_cold_boot_setup() is not supposed to return */
no_ret plat_panic_handler
do_primary_cold_boot:
.endif /* _secondary_cold_boot */
/* ---------------------------------------------------------------------
* Initialize memory now. Secondary CPU initialization won't get to this
* point.
* ---------------------------------------------------------------------
*/
.if \_init_memory
bl platform_mem_init
.endif /* _init_memory */
/* ---------------------------------------------------------------------
* Init C runtime environment:
* - Zero-initialise the NOBITS sections. There are 2 of them:
* - the .bss section;
* - the coherent memory section (if any).
* - Relocate the data section from ROM to RAM, if required.
* ---------------------------------------------------------------------
*/
.if \_init_c_runtime
#if IMAGE_BL32
/* -----------------------------------------------------------------
* Invalidate the RW memory used by the BL32 (SP_MIN) image. This
* includes the data and NOBITS sections. This is done to
* safeguard against possible corruption of this memory by
* dirty cache lines in a system cache as a result of use by
* an earlier boot loader stage.
* -----------------------------------------------------------------
*/
ldr r0, =__RW_START__
ldr r1, =__RW_END__
sub r1, r1, r0
bl inv_dcache_range
#endif /* IMAGE_BL32 */
ldr r0, =__BSS_START__
ldr r1, =__BSS_SIZE__
bl zeromem
#if USE_COHERENT_MEM
ldr r0, =__COHERENT_RAM_START__
ldr r1, =__COHERENT_RAM_UNALIGNED_SIZE__
bl zeromem
#endif
#if IMAGE_BL1
/* -----------------------------------------------------
* Copy data from ROM to RAM.
* -----------------------------------------------------
*/
ldr r0, =__DATA_RAM_START__
ldr r1, =__DATA_ROM_START__
ldr r2, =__DATA_SIZE__
bl memcpy4
#endif
.endif /* _init_c_runtime */
/* ---------------------------------------------------------------------
* Allocate a stack whose memory will be marked as Normal-IS-WBWA when
* the MMU is enabled. There is no risk of reading stale stack memory
* after enabling the MMU as only the primary CPU is running at the
* moment.
* ---------------------------------------------------------------------
*/
bl plat_set_my_stack
.endm
#endif /* __EL3_COMMON_MACROS_S__ */