• Juan Castillo's avatar
    TBB: authenticate BL2 image and certificate · 01df3c14
    Juan Castillo authored
    This patch adds support to authenticate the BL2 content certificate
    and image using the authentication module in BL1.
    
    The FIP driver has been extended to include the BL2 certificate
    UUID.
    
    FVP and Juno ports include the BL2 certificate FIP file
    definition.
    
    Change-Id: I32680e9bd123c8db4a4193c14448c9b32b0e9325
    01df3c14
bl1_main.c 8.13 KB
/*
 * 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 <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <auth.h>
#include <bl_common.h>
#include <debug.h>
#include <platform.h>
#include <platform_def.h>
#include "bl1_private.h"

/*******************************************************************************
 * Runs BL2 from the given entry point. It results in dropping the
 * exception level
 ******************************************************************************/
static void __dead2 bl1_run_bl2(entry_point_info_t *bl2_ep)
{
	bl1_arch_next_el_setup();

	/* Tell next EL what we want done */
	bl2_ep->args.arg0 = RUN_IMAGE;

	if (GET_SECURITY_STATE(bl2_ep->h.attr) == NON_SECURE)
		change_security_state(GET_SECURITY_STATE(bl2_ep->h.attr));

	write_spsr_el3(bl2_ep->spsr);
	write_elr_el3(bl2_ep->pc);

	eret(bl2_ep->args.arg0,
		bl2_ep->args.arg1,
		bl2_ep->args.arg2,
		bl2_ep->args.arg3,
		bl2_ep->args.arg4,
		bl2_ep->args.arg5,
		bl2_ep->args.arg6,
		bl2_ep->args.arg7);
}

/*******************************************************************************
 * 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 locates and loads the BL2 raw binary image in the trusted DRAM. Only
 * 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_main(void)
{
	/* 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 sctlr_el3 = read_sctlr_el3();
#endif
	image_info_t bl2_image_info = { {0} };
	entry_point_info_t bl2_ep = { {0} };
	meminfo_t *bl1_tzram_layout;
	meminfo_t *bl2_tzram_layout = 0x0;
	int err;

	/*
	 * Ensure that MMU/Caches and coherency are turned on
	 */
	assert(sctlr_el3 | SCTLR_M_BIT);
	assert(sctlr_el3 | SCTLR_C_BIT);
	assert(sctlr_el3 | SCTLR_I_BIT);

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

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

	SET_PARAM_HEAD(&bl2_image_info, PARAM_IMAGE_BINARY, VERSION_1, 0);
	SET_PARAM_HEAD(&bl2_ep, PARAM_EP, VERSION_1, 0);

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

#if TRUSTED_BOARD_BOOT
	/* Initialize authentication module */
	auth_init();

	/*
	 * Load the BL2 certificate into the BL2 region. This region will be
	 * overwritten by the image, so the authentication module is responsible
	 * for storing the relevant data from the certificate (keys, hashes,
	 * etc.) so it can be used later.
	 */
	err = load_image(bl1_tzram_layout,
			 BL2_CERT_NAME,
			 BL2_BASE,
			 &bl2_image_info,
			 NULL);
	if (err) {
		ERROR("Failed to load BL2 certificate.\n");
		panic();
	}

	err = auth_verify_obj(AUTH_BL2_IMG_CERT, bl2_image_info.image_base,
			bl2_image_info.image_size);
	if (err) {
		ERROR("Failed to validate BL2 certificate.\n");
		panic();
	}
#endif /* TRUSTED_BOARD_BOOT */

	/* Load the BL2 image */
	err = load_image(bl1_tzram_layout,
			 BL2_IMAGE_NAME,
			 BL2_BASE,
			 &bl2_image_info,
			 &bl2_ep);
	if (err) {
		/*
		 * TODO: print failure to load BL2 but also add a tzwdog timer
		 * which will reset the system eventually.
		 */
		ERROR("Failed to load BL2 firmware.\n");
		panic();
	}

#if TRUSTED_BOARD_BOOT
	err = auth_verify_obj(AUTH_BL2_IMG, bl2_image_info.image_base,
				bl2_image_info.image_size);
	if (err) {
		ERROR("Failed to validate BL2 image.\n");
		panic();
	}

	/* After working with data, invalidate the data cache */
	inv_dcache_range(bl2_image_info.image_base,
			(size_t)bl2_image_info.image_size);
#endif /* TRUSTED_BOARD_BOOT */

	/*
	 * 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);

	bl1_plat_set_bl2_ep_info(&bl2_image_info, &bl2_ep);
	bl2_ep.args.arg1 = (unsigned long)bl2_tzram_layout;
	NOTICE("BL1: Booting BL2\n");
	INFO("BL1: BL2 address = 0x%llx\n",
		(unsigned long long) bl2_ep.pc);
	INFO("BL1: BL2 spsr = 0x%x\n", bl2_ep.spsr);
	VERBOSE("BL1: BL2 memory layout address = 0x%llx\n",
		(unsigned long long) bl2_tzram_layout);

	bl1_run_bl2(&bl2_ep);

	return;
}

/*******************************************************************************
 * Temporary function to print the fact that BL2 has done its job and BL31 is
 * about to be loaded. This is needed as long as printfs cannot be used
 ******************************************************************************/
void display_boot_progress(entry_point_info_t *bl31_ep_info)
{
	NOTICE("BL1: Booting BL3-1\n");
	INFO("BL1: BL3-1 address = 0x%llx\n",
		(unsigned long long)bl31_ep_info->pc);
	INFO("BL1: BL3-1 spsr = 0x%llx\n",
		(unsigned long long)bl31_ep_info->spsr);
	INFO("BL1: BL3-1 params address = 0x%llx\n",
		(unsigned long long)bl31_ep_info->args.arg0);
	INFO("BL1: BL3-1 plat params address = 0x%llx\n",
		(unsigned long long)bl31_ep_info->args.arg1);
}