• 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 procedure
    	to mark completion of the FWU process.
    	The weak definition waits forever calling `wfi()`.
    
    plat_bl1_common.c contains weak definitions for above functions.
    
    FWU process starts when platform detects it and return the image_id
    other than BL2_IMAGE_ID by using `bl1_plat_get_next_image_id()` in
    `bl1_main()`.
    
    NOTE: User MUST provide platform specific real definition for
    bl1_plat_mem_check() in order to use it for Firmware update.
    
    Change-Id: Ice189a0885d9722d9e1dd03f76cac1aceb0e25ed
    48bfb88e
bl1_main.c 8.45 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 <arch_helpers.h>
#include <assert.h>
#include <auth_mod.h>
#include <bl1.h>
#include <bl_common.h>
#include <debug.h>
#include <platform.h>
#include <platform_def.h>
#include <smcc_helpers.h>
#include "bl1_private.h"
#include <uuid.h>

/* BL1 Service UUID */
DEFINE_SVC_UUID(bl1_svc_uid,
	0xfd3967d4, 0x72cb, 0x4d9a, 0xb5, 0x75,
	0x67, 0x15, 0xd6, 0xf4, 0xbb, 0x4a);


static void bl1_load_bl2(void);

/*******************************************************************************
 * The next function has a weak definition. Platform specific code can override
 * it if it wishes to.
 ******************************************************************************/
#pragma weak bl1_init_bl2_mem_layout

/*******************************************************************************
 * Function that takes a memory layout into which BL2 has been loaded and
 * populates a new memory layout for BL2 that ensures that BL1's data sections
 * resident in secure RAM are not visible to BL2.
 ******************************************************************************/
void bl1_init_bl2_mem_layout(const meminfo_t *bl1_mem_layout,
			     meminfo_t *bl2_mem_layout)
{
	const size_t bl1_size = BL1_RAM_LIMIT - BL1_RAM_BASE;

	assert(bl1_mem_layout != NULL);
	assert(bl2_mem_layout != NULL);

	/* Check that BL1's memory is lying outside of the free memory */
	assert((BL1_RAM_LIMIT <= bl1_mem_layout->free_base) ||
	       (BL1_RAM_BASE >= bl1_mem_layout->free_base +
				bl1_mem_layout->free_size));

	/* Remove BL1 RW data from the scope of memory visible to BL2 */
	*bl2_mem_layout = *bl1_mem_layout;
	reserve_mem(&bl2_mem_layout->total_base,
		    &bl2_mem_layout->total_size,
		    BL1_RAM_BASE,
		    bl1_size);

	flush_dcache_range((unsigned long)bl2_mem_layout, sizeof(meminfo_t));
}

/*******************************************************************************
 * Function to perform late architectural and platform specific initialization.
 * It also queries the platform to load and run next BL image. Only called
 * by the primary cpu after a cold boot.
 ******************************************************************************/
void bl1_main(void)
{
	unsigned int image_id;

	/* Announce our arrival */
	NOTICE(FIRMWARE_WELCOME_STR);
	NOTICE("BL1: %s\n", version_string);
	NOTICE("BL1: %s\n", build_message);

	INFO("BL1: RAM 0x%lx - 0x%lx\n", BL1_RAM_BASE, BL1_RAM_LIMIT);


#if DEBUG
	unsigned long val;
	/*
	 * Ensure that MMU/Caches and coherency are turned on
	 */
	val = read_sctlr_el3();
	assert(val & SCTLR_M_BIT);
	assert(val & SCTLR_C_BIT);
	assert(val & SCTLR_I_BIT);
	/*
	 * Check that Cache Writeback Granule (CWG) in CTR_EL0 matches the
	 * provided platform value
	 */
	val = (read_ctr_el0() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
	/*
	 * If CWG is zero, then no CWG information is available but we can
	 * at least check the platform value is less than the architectural
	 * maximum.
	 */
	if (val != 0)
		assert(CACHE_WRITEBACK_GRANULE == SIZE_FROM_LOG2_WORDS(val));
	else
		assert(CACHE_WRITEBACK_GRANULE <= MAX_CACHE_LINE_SIZE);
#endif

	/* Perform remaining generic architectural setup from EL3 */
	bl1_arch_setup();

#if TRUSTED_BOARD_BOOT
	/* Initialize authentication module */
	auth_mod_init();
#endif /* TRUSTED_BOARD_BOOT */

	/* Perform platform setup in BL1. */
	bl1_platform_setup();

	/* Get the image id of next image to load and run. */
	image_id = bl1_plat_get_next_image_id();

	/*
	 * We currently interpret any image id other than
	 * BL2_IMAGE_ID as the start of firmware update.
	 */
	if (image_id == BL2_IMAGE_ID)
		bl1_load_bl2();
	else
		NOTICE("BL1-FWU: *******FWU Process Started*******\n");

	bl1_prepare_next_image(image_id);
}

/*******************************************************************************
 * This function locates and loads the BL2 raw binary image in the trusted SRAM.
 * Called by the primary cpu after a cold boot.
 * TODO: Add support for alternative image load mechanism e.g using virtio/elf
 * loader etc.
 ******************************************************************************/
void bl1_load_bl2(void)
{
	image_desc_t *image_desc;
	image_info_t *image_info;
	entry_point_info_t *ep_info;
	meminfo_t *bl1_tzram_layout;
	meminfo_t *bl2_tzram_layout;
	int err;

	/* Get the image descriptor */
	image_desc = bl1_plat_get_image_desc(BL2_IMAGE_ID);
	assert(image_desc);

	/* Get the image info */
	image_info = &image_desc->image_info;

	/* Get the entry point info */
	ep_info = &image_desc->ep_info;

	/* Find out how much free trusted ram remains after BL1 load */
	bl1_tzram_layout = bl1_plat_sec_mem_layout();

	INFO("BL1: Loading BL2\n");

	/* Load the BL2 image */
	err = load_auth_image(bl1_tzram_layout,
			 BL2_IMAGE_ID,
			 image_info->image_base,
			 image_info,
			 ep_info);

	if (err) {
		ERROR("Failed to load BL2 firmware.\n");
		plat_error_handler(err);
	}

	/*
	 * Create a new layout of memory for BL2 as seen by BL1 i.e.
	 * tell it the amount of total and free memory available.
	 * This layout is created at the first free address visible
	 * to BL2. BL2 will read the memory layout before using its
	 * memory for other purposes.
	 */
	bl2_tzram_layout = (meminfo_t *) bl1_tzram_layout->free_base;
	bl1_init_bl2_mem_layout(bl1_tzram_layout, bl2_tzram_layout);

	ep_info->args.arg1 = (unsigned long)bl2_tzram_layout;
	NOTICE("BL1: Booting BL2\n");
	VERBOSE("BL1: BL2 memory layout address = 0x%llx\n",
		(unsigned long long) bl2_tzram_layout);
}

/*******************************************************************************
 * Function called just before handing over to BL31 to inform the user about
 * the boot progress. In debug mode, also print details about the BL31 image's
 * execution context.
 ******************************************************************************/
void bl1_print_bl31_ep_info(const entry_point_info_t *bl31_ep_info)
{
	NOTICE("BL1: Booting BL3-1\n");
	print_entry_point_info(bl31_ep_info);
}

#if SPIN_ON_BL1_EXIT
void print_debug_loop_message(void)
{
	NOTICE("BL1: Debug loop, spinning forever\n");
	NOTICE("BL1: Please connect the debugger to continue\n");
}
#endif

/*******************************************************************************
 * Top level handler for servicing BL1 SMCs.
 ******************************************************************************/
register_t bl1_smc_handler(unsigned int smc_fid,
	register_t x1,
	register_t x2,
	register_t x3,
	register_t x4,
	void *cookie,
	void *handle,
	unsigned int flags)
{

#if TRUSTED_BOARD_BOOT
	/*
	 * Dispatch FWU calls to FWU SMC handler and return its return
	 * value
	 */
	if (is_fwu_fid(smc_fid)) {
		return bl1_fwu_smc_handler(smc_fid, x1, x2, x3, x4, cookie,
			handle, flags);
	}
#endif

	switch (smc_fid) {
	case BL1_SMC_CALL_COUNT:
		SMC_RET1(handle, BL1_NUM_SMC_CALLS);

	case BL1_SMC_UID:
		SMC_UUID_RET(handle, bl1_svc_uid);

	case BL1_SMC_VERSION:
		SMC_RET1(handle, BL1_SMC_MAJOR_VER | BL1_SMC_MINOR_VER);

	default:
		break;
	}

	WARN("Unimplemented BL1 SMC Call: 0x%x \n", smc_fid);
	SMC_RET1(handle, SMC_UNK);
}