arm-trusted-firmware/bl31/aarch64/bl31_entrypoint.S
Sandrine Bailleux 52010cc779 Rationalize reset handling code
The attempt to run the CPU reset code as soon as possible after reset
results in highly complex conditional code relating to the
RESET_TO_BL31 option.

This patch relaxes this requirement a little. In the BL1, BL3-1 and
PSCI entrypoints code, the sequence of operations is now as follows:
 1) Detect whether it is a cold or warm boot;
 2) For cold boot, detect whether it is the primary or a secondary
    CPU. This is needed to handle multiple CPUs entering cold reset
    simultaneously;
 3) Run the CPU init code.

This patch also abstracts the EL3 registers initialisation done by
the BL1, BL3-1 and PSCI entrypoints into common code.

This improves code re-use and consolidates the code flows for
different types of systems.

NOTE: THE FUNCTION plat_secondary_cold_boot() IS NOW EXPECTED TO
NEVER RETURN. THIS PATCH FORCES PLATFORM PORTS THAT RELIED ON THE
FORMER RETRY LOOP AT THE CALL SITE TO MODIFY THEIR IMPLEMENTATION.
OTHERWISE, SECONDARY CPUS WILL PANIC.

Change-Id: If5ecd74d75bee700b1bd718d23d7556b8f863546
2015-06-04 11:38:54 +01:00

111 lines
4.1 KiB
ArmAsm

/*
* Copyright (c) 2013-2015, 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.
*
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* 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.
*/
#include <arch.h>
#include <bl_common.h>
#include <el3_common_macros.S>
.globl bl31_entrypoint
/* -----------------------------------------------------
* bl31_entrypoint() is the cold boot entrypoint,
* executed only by the primary cpu.
* -----------------------------------------------------
*/
func bl31_entrypoint
#if !RESET_TO_BL31
/* ---------------------------------------------------------------
* Preceding bootloader has populated x0 with a pointer to a
* 'bl31_params' structure & x1 with a pointer to platform
* specific structure
* ---------------------------------------------------------------
*/
mov x20, x0
mov x21, x1
/* ---------------------------------------------------------------------
* For !RESET_TO_BL31 systems, only the primary CPU ever reaches
* bl31_entrypoint() during the cold boot flow, so the cold/warm boot
* and primary/secondary CPU logic should not be executed in this case.
*
* Also, assume that the previous bootloader has already set up the CPU
* endianness and has initialised the memory.
* ---------------------------------------------------------------------
*/
el3_entrypoint_common \
_set_endian=0 \
_warm_boot_mailbox=0 \
_secondary_cold_boot=0 \
_init_memory=0 \
_init_c_runtime=1 \
_exception_vectors=runtime_exceptions
/* ---------------------------------------------------------------------
* Relay the previous bootloader's arguments to the platform layer
* ---------------------------------------------------------------------
*/
mov x0, x20
mov x1, x21
#else
el3_entrypoint_common \
_set_endian=1 \
_warm_boot_mailbox=1 \
_secondary_cold_boot=1 \
_init_memory=1 \
_init_c_runtime=1 \
_exception_vectors=runtime_exceptions
/* ---------------------------------------------------------------------
* For RESET_TO_BL31 systems, BL3-1 is the first bootloader to run so
* there's no argument to relay from a previous bootloader. Zero the
* arguments passed to the platform layer to reflect that.
* ---------------------------------------------------------------------
*/
mov x0, 0
mov x1, 0
#endif /* RESET_TO_BL31 */
/* ---------------------------------------------
* Perform platform specific early arch. setup
* ---------------------------------------------
*/
bl bl31_early_platform_setup
bl bl31_plat_arch_setup
/* ---------------------------------------------
* Jump to main function.
* ---------------------------------------------
*/
bl bl31_main
b el3_exit
endfunc bl31_entrypoint