arm-trusted-firmware/bl2/aarch64/bl2_entrypoint.S
Soby Mathew a6f340fe58 Introduce the new BL handover interface
This patch introduces a new BL handover interface. It essentially allows
passing 4 arguments between the different BL stages. Effort has been made
so as to be compatible with the previous handover interface. The previous
blx_early_platform_setup() platform API is now deprecated and the new
blx_early_platform_setup2() variant is introduced. The weak compatiblity
implementation for the new API is done in the `plat_bl_common.c` file.
Some of the new arguments in the new API will be reserved for generic
code use when dynamic configuration support is implemented. Otherwise
the other registers are available for platform use.

Change-Id: Ifddfe2ea8e32497fe1beb565cac155ad9d50d404
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
2018-02-26 16:31:10 +00:00

127 lines
3.2 KiB
ArmAsm

/*
* Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch.h>
#include <asm_macros.S>
#include <bl_common.h>
.globl bl2_entrypoint
func bl2_entrypoint
/*---------------------------------------------
* Save arguments x0 - x3 from BL1 for future
* use.
* ---------------------------------------------
*/
mov x20, x0
mov x21, x1
mov x22, x2
mov x23, x3
/* ---------------------------------------------
* Set the exception vector to something sane.
* ---------------------------------------------
*/
adr x0, early_exceptions
msr vbar_el1, x0
isb
/* ---------------------------------------------
* Enable the SError interrupt now that the
* exception vectors have been setup.
* ---------------------------------------------
*/
msr daifclr, #DAIF_ABT_BIT
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, x1
msr sctlr_el1, x0
isb
/* ---------------------------------------------
* Invalidate the RW memory used by the BL2
* 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.
* ---------------------------------------------
*/
adr x0, __RW_START__
adr x1, __RW_END__
sub x1, x1, x0
bl inv_dcache_range
/* ---------------------------------------------
* Zero out NOBITS sections. There are 2 of them:
* - the .bss section;
* - the coherent memory section.
* ---------------------------------------------
*/
ldr x0, =__BSS_START__
ldr x1, =__BSS_SIZE__
bl zeromem
#if USE_COHERENT_MEM
ldr x0, =__COHERENT_RAM_START__
ldr x1, =__COHERENT_RAM_UNALIGNED_SIZE__
bl zeromem
#endif
/* --------------------------------------------
* 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
/* ---------------------------------------------
* Initialize the stack protector canary before
* any C code is called.
* ---------------------------------------------
*/
#if STACK_PROTECTOR_ENABLED
bl update_stack_protector_canary
#endif
/* ---------------------------------------------
* Perform early platform setup & platform
* specific early arch. setup e.g. mmu setup
* ---------------------------------------------
*/
mov x0, x20
mov x1, x21
mov x2, x22
mov x3, x23
bl bl2_early_platform_setup2
bl bl2_plat_arch_setup
/* ---------------------------------------------
* Jump to main function.
* ---------------------------------------------
*/
bl bl2_main
/* ---------------------------------------------
* Should never reach this point.
* ---------------------------------------------
*/
no_ret plat_panic_handler
endfunc bl2_entrypoint