• Yatharth Kochar's avatar
    FWU: Add Generic Firmware Update framework support in BL1 · 48bfb88e
    Yatharth Kochar authored
    Firmware update(a.k.a FWU) feature is part of the TBB architecture.
    BL1 is responsible for carrying out the FWU process if platform
    specific code detects that it is needed.
    
    This patch adds support for FWU feature support in BL1 which is
    included by enabling `TRUSTED_BOARD_BOOT` compile time flag.
    
    This patch adds bl1_fwu.c which contains all the core operations
    of FWU, which are; SMC handler, image copy, authentication, execution
    and resumption. It also adds bl1.h introducing #defines for all
    BL1 SMCs.
    
    Following platform porting functions are introduced:
    
    int bl1_plat_mem_check(uintptr_t mem_base, unsigned int mem_size,
    unsigned int flags);
    	This function can be used to add platform specific memory checks
    	for the provided base/size for the given security state.
    	The weak definition will invoke `assert()` and return -ENOMEM.
    
    __dead2 void bl1_plat_fwu_done(void *cookie, void *reserved);
    	This function can be used to initiate platform specific pro...
    48bfb88e
bl1_exceptions.S 8.51 KB
/*
 * 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.
 *
 * 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 <arch.h>
#include <asm_macros.S>
#include <bl_common.h>
#include <bl1.h>
#include <context.h>

	.globl	bl1_exceptions

	.section	.vectors, "ax"; .align 11

	/* -----------------------------------------------------
	 * Very simple stackless exception handlers used by BL1.
	 * -----------------------------------------------------
	 */
	.align	7
bl1_exceptions:
	/* -----------------------------------------------------
	 * Current EL with SP0 : 0x0 - 0x200
	 * -----------------------------------------------------
	 */
SynchronousExceptionSP0:
	mov	x0, #SYNC_EXCEPTION_SP_EL0
	bl	plat_report_exception
	b	SynchronousExceptionSP0
	check_vector_size SynchronousExceptionSP0

	.align	7
IrqSP0:
	mov	x0, #IRQ_SP_EL0
	bl	plat_report_exception
	b	IrqSP0
	check_vector_size IrqSP0

	.align	7
FiqSP0:
	mov	x0, #FIQ_SP_EL0
	bl	plat_report_exception
	b	FiqSP0
	check_vector_size FiqSP0

	.align	7
SErrorSP0:
	mov	x0, #SERROR_SP_EL0
	bl	plat_report_exception
	b	SErrorSP0
	check_vector_size SErrorSP0

	/* -----------------------------------------------------
	 * Current EL with SPx: 0x200 - 0x400
	 * -----------------------------------------------------
	 */
	.align	7
SynchronousExceptionSPx:
	mov	x0, #SYNC_EXCEPTION_SP_ELX
	bl	plat_report_exception
	b	SynchronousExceptionSPx
	check_vector_size SynchronousExceptionSPx

	.align	7
IrqSPx:
	mov	x0, #IRQ_SP_ELX
	bl	plat_report_exception
	b	IrqSPx
	check_vector_size IrqSPx

	.align	7
FiqSPx:
	mov	x0, #FIQ_SP_ELX
	bl	plat_report_exception
	b	FiqSPx
	check_vector_size FiqSPx

	.align	7
SErrorSPx:
	mov	x0, #SERROR_SP_ELX
	bl	plat_report_exception
	b	SErrorSPx
	check_vector_size SErrorSPx

	/* -----------------------------------------------------
	 * Lower EL using AArch64 : 0x400 - 0x600
	 * -----------------------------------------------------
	 */
	.align	7
SynchronousExceptionA64:
	/* Enable the SError interrupt */
	msr	daifclr, #DAIF_ABT_BIT

	str	x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]

	/* Expect only SMC exceptions */
	mrs	x30, esr_el3
	ubfx	x30, x30, #ESR_EC_SHIFT, #ESR_EC_LENGTH
	cmp	x30, #EC_AARCH64_SMC
	b.ne	unexpected_sync_exception

	b	smc_handler64
	check_vector_size SynchronousExceptionA64

	.align	7
IrqA64:
	mov	x0, #IRQ_AARCH64
	bl	plat_report_exception
	b	IrqA64
	check_vector_size IrqA64

	.align	7
FiqA64:
	mov	x0, #FIQ_AARCH64
	bl	plat_report_exception
	b	FiqA64
	check_vector_size FiqA64

	.align	7
SErrorA64:
	mov	x0, #SERROR_AARCH64
	bl	plat_report_exception
	b   	SErrorA64
	check_vector_size SErrorA64

	/* -----------------------------------------------------
	 * Lower EL using AArch32 : 0x600 - 0x800
	 * -----------------------------------------------------
	 */
	.align	7
SynchronousExceptionA32:
	mov	x0, #SYNC_EXCEPTION_AARCH32
	bl	plat_report_exception
	b	SynchronousExceptionA32
	check_vector_size SynchronousExceptionA32

	.align	7
IrqA32:
	mov	x0, #IRQ_AARCH32
	bl	plat_report_exception
	b	IrqA32
	check_vector_size IrqA32

	.align	7
FiqA32:
	mov	x0, #FIQ_AARCH32
	bl	plat_report_exception
	b	FiqA32
	check_vector_size FiqA32

	.align	7
SErrorA32:
	mov	x0, #SERROR_AARCH32
	bl	plat_report_exception
	b	SErrorA32
	check_vector_size SErrorA32


func smc_handler64

	/* ----------------------------------------------
	 * Detect if this is a RUN_IMAGE or other SMC.
	 * ----------------------------------------------
	 */
	mov	x30, #BL1_SMC_RUN_IMAGE
	cmp	x30, x0
	b.ne	smc_handler

	/* ------------------------------------------------
	 * Make sure only Secure world reaches here.
	 * ------------------------------------------------
	 */
	mrs	x30, scr_el3
	tst	x30, #SCR_NS_BIT
	b.ne	unexpected_sync_exception

	/* ----------------------------------------------
	 * Handling RUN_IMAGE SMC. First switch back to
	 * SP_EL0 for the C runtime stack.
	 * ----------------------------------------------
	 */
	ldr	x30, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]
	msr	spsel, #0
	mov	sp, x30

	/* ---------------------------------------------------------------------
	 * Pass EL3 control to BL31.
	 * Here it expects X1 with the address of a entry_point_info_t
	 * structure describing the BL31 entrypoint.
	 * ---------------------------------------------------------------------
	 */
	mov	x20, x1

	mov	x0, x20
	bl	bl1_print_bl31_ep_info

	ldp	x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]
	msr	elr_el3, x0
	msr	spsr_el3, x1
	ubfx	x0, x1, #MODE_EL_SHIFT, #2
	cmp	x0, #MODE_EL3
	b.ne	unexpected_sync_exception

	bl	disable_mmu_icache_el3
	tlbi	alle3

#if SPIN_ON_BL1_EXIT
	bl	print_debug_loop_message
debug_loop:
	b	debug_loop
#endif

	mov	x0, x20
	bl	bl1_plat_prepare_exit

	ldp	x6, x7, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x30)]
	ldp	x4, x5, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x20)]
	ldp	x2, x3, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x10)]
	ldp	x0, x1, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x0)]
	eret
endfunc smc_handler64

unexpected_sync_exception:
	mov	x0, #SYNC_EXCEPTION_AARCH64
	bl	plat_report_exception
	wfi
	b	unexpected_sync_exception

	/* -----------------------------------------------------
	 * Save Secure/Normal world context and jump to
	 * BL1 SMC handler.
	 * -----------------------------------------------------
	 */
smc_handler:
	/* -----------------------------------------------------
	 * Save the GP registers x0-x29.
	 * TODO: Revisit to store only SMCC specified registers.
	 * -----------------------------------------------------
	 */
	bl	save_gp_registers

	/* -----------------------------------------------------
	 * Populate the parameters for the SMC handler. We
	 * already have x0-x4 in place. x5 will point to a
	 * cookie (not used now). x6 will point to the context
	 * structure (SP_EL3) and x7 will contain flags we need
	 * to pass to the handler.
	 * -----------------------------------------------------
	 */
	mov	x5, xzr
	mov	x6, sp

	/* -----------------------------------------------------
	 * Restore the saved C runtime stack value which will
	 * become the new SP_EL0 i.e. EL3 runtime stack. It was
	 * saved in the 'cpu_context' structure prior to the last
	 * ERET from EL3.
	 * -----------------------------------------------------
	 */
	ldr	x12, [x6, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP]

	/* ---------------------------------------------
	 * Switch back to SP_EL0 for the C runtime stack.
	 * ---------------------------------------------
	 */
	msr	spsel, #0
	mov	sp, x12

	/* -----------------------------------------------------
	 * Save the SPSR_EL3, ELR_EL3, & SCR_EL3 in case there
	 * is a world switch during SMC handling.
	 * -----------------------------------------------------
	 */
	mrs	x16, spsr_el3
	mrs	x17, elr_el3
	mrs	x18, scr_el3
	stp	x16, x17, [x6, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3]
	str	x18, [x6, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3]

	/* Copy SCR_EL3.NS bit to the flag to indicate caller's security */
	bfi	x7, x18, #0, #1

	/* -----------------------------------------------------
	 * Go to BL1 SMC handler.
	 * -----------------------------------------------------
	 */
	bl	bl1_smc_handler

	/* -----------------------------------------------------
	 * Do the transition to next BL image.
	 * -----------------------------------------------------
	 */
	b	el3_exit