tsp_entrypoint.S

/*
 * Copyright (c) 2013-2014, 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.
 */

#include <bl_common.h>
#include <arch.h>
#include <tsp.h>


	.globl	tsp_entrypoint
	.globl	tsp_cpu_on_entry
	.globl	tsp_cpu_off_entry
	.globl	tsp_cpu_suspend_entry
	.globl	tsp_cpu_resume_entry
	.globl	tsp_fast_smc_entry

	/* ---------------------------------------------
	 * Populate the params in x0-x7 from the pointer
	 * to the smc args structure in x0.
	 * ---------------------------------------------
	 */
	.macro restore_args_call_smc
	ldp	x6, x7, [x0, #TSP_ARG6]
	ldp	x4, x5, [x0, #TSP_ARG4]
	ldp	x2, x3, [x0, #TSP_ARG2]
	ldp	x0, x1, [x0, #TSP_ARG0]
	smc	#0
	.endm

	.section	.text, "ax"; .align 3


tsp_entrypoint: ; .type tsp_entrypoint, %function
	/*---------------------------------------------
	 * Store the extents of the tzram available to
	 * BL32 for future use.
	 * TODO: We are assuming that x9-x10 will not be
	 * corrupted by any function before platform
	 * setup.
	 * ---------------------------------------------
	 */
	mov	x9, x0
	mov	x10, x1

	/* ---------------------------------------------
	 * The entrypoint is expected to be executed
	 * only by the primary cpu (at least for now).
	 * So, make sure no secondary has lost its way.
	 * ---------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_is_primary_cpu
	cbz	x0, tsp_entrypoint_panic

	/* ---------------------------------------------
	 * Set the exception vector to something sane.
	 * ---------------------------------------------
	 */
	adr	x0, early_exceptions
	msr	vbar_el1, x0

	/* ---------------------------------------------
	 * Enable the instruction cache.
	 * ---------------------------------------------
	 */
	mrs	x0, sctlr_el1
	orr	x0, x0, #SCTLR_I_BIT
	msr	sctlr_el1, x0
	isb

	/* ---------------------------------------------
	 * 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	zeromem16

	ldr	x0, =__COHERENT_RAM_START__
	ldr	x1, =__COHERENT_RAM_UNALIGNED_SIZE__
	bl	zeromem16

	/* --------------------------------------------
	 * Give ourselves a small coherent stack to
	 * ease the pain of initializing the MMU
	 * --------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_set_coherent_stack

	/* ---------------------------------------------
	 * Perform early platform setup & platform
	 * specific early arch. setup e.g. mmu setup
	 * ---------------------------------------------
	 */
	mov	x0, x9
	mov	x1, x10
	bl	bl32_early_platform_setup
	bl	bl32_plat_arch_setup

	/* ---------------------------------------------
	 * Give ourselves a stack allocated in Normal
	 * -IS-WBWA memory
	 * ---------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_set_stack

	/* ---------------------------------------------
	 * Jump to main function.
	 * ---------------------------------------------
	 */
	bl	tsp_main

	/* ---------------------------------------------
	 * Tell TSPD that we are done initialising
	 * ---------------------------------------------
	 */
	mov	x1, x0
	mov	x0, #TSP_ENTRY_DONE
	smc	#0

tsp_entrypoint_panic:
	b	tsp_entrypoint_panic

	/*---------------------------------------------
	 * This entrypoint is used by the TSPD when this
	 * cpu is to be turned off through a CPU_OFF
	 * psci call to ask the TSP to perform any
	 * bookeeping necessary. In the current
	 * implementation, the TSPD expects the TSP to
	 * re-initialise its state so nothing is done
	 * here except for acknowledging the request.
	 * ---------------------------------------------
	 */
tsp_cpu_off_entry: ; .type tsp_cpu_off_entry, %function
	bl	tsp_cpu_off_main
	restore_args_call_smc

	/*---------------------------------------------
	 * This entrypoint is used by the TSPD when this
	 * cpu is turned on using a CPU_ON psci call to
	 * ask the TSP to initialise itself i.e. setup
	 * the mmu, stacks etc. Minimal architectural
	 * state will be initialised by the TSPD when
	 * this function is entered i.e. Caches and MMU
	 * will be turned off, the execution state
	 * will be aarch64 and exceptions masked.
	 * ---------------------------------------------
	 */
tsp_cpu_on_entry: ; .type tsp_cpu_on_entry, %function
	/* ---------------------------------------------
	 * Set the exception vector to something sane.
	 * ---------------------------------------------
	 */
	adr	x0, early_exceptions
	msr	vbar_el1, x0

	/* ---------------------------------------------
	 * Enable the instruction cache.
	 * ---------------------------------------------
	 */
	mrs	x0, sctlr_el1
	orr	x0, x0, #SCTLR_I_BIT
	msr	sctlr_el1, x0
	isb

	/* --------------------------------------------
	 * Give ourselves a small coherent stack to
	 * ease the pain of initializing the MMU
	 * --------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_set_coherent_stack

	/* ---------------------------------------------
	 * Initialise the MMU
	 * ---------------------------------------------
	 */
	bl	enable_mmu

	/* ---------------------------------------------
	 * Give ourselves a stack allocated in Normal
	 * -IS-WBWA memory
	 * ---------------------------------------------
	 */
	mrs	x0, mpidr_el1
	bl	platform_set_stack

	/* ---------------------------------------------
	 * Enter C runtime to perform any remaining
	 * book keeping
	 * ---------------------------------------------
	 */
	bl	tsp_cpu_on_main
	restore_args_call_smc

	/* Should never reach here */
tsp_cpu_on_entry_panic:
	b	tsp_cpu_on_entry_panic

	/*---------------------------------------------
	 * This entrypoint is used by the TSPD when this
	 * cpu is to be suspended through a CPU_SUSPEND
	 * psci call to ask the TSP to perform any
	 * bookeeping necessary. In the current
	 * implementation, the TSPD saves and restores
	 * the EL1 state.
	 * ---------------------------------------------
	 */
tsp_cpu_suspend_entry: ; .type tsp_cpu_suspend_entry, %function
	bl	tsp_cpu_suspend_main
	restore_args_call_smc

	/*---------------------------------------------
	 * This entrypoint is used by the TSPD when this
	 * cpu resumes execution after an earlier
	 * CPU_SUSPEND psci call to ask the TSP to
	 * restore its saved context. In the current
	 * implementation, the TSPD saves and restores
	 * EL1 state so nothing is done here apart from
	 * acknowledging the request.
	 * ---------------------------------------------
	 */
tsp_cpu_resume_entry: ; .type tsp_cpu_resume_entry, %function
	bl	tsp_cpu_resume_main
	restore_args_call_smc
tsp_cpu_resume_panic:
	b	tsp_cpu_resume_panic

	/*---------------------------------------------
	 * This entrypoint is used by the TSPD to ask
	 * the TSP to service a fast smc request.
	 * ---------------------------------------------
	 */
tsp_fast_smc_entry: ; .type tsp_fast_smc_entry, %function
	bl	tsp_fast_smc_handler
	restore_args_call_smc
tsp_fast_smc_entry_panic:
	b	tsp_fast_smc_entry_panic