arm-trusted-firmware/bl2/bl2_main.c

/*
 * Copyright (c) 2013-2026, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <assert.h>

#include <arch.h>
#include <arch_helpers.h>
#include <arch_features.h>
#include <bl1/bl1.h>
#include <bl2/bl2.h>
#include <common/bl_common.h>
#include <common/build_message.h>
#include <common/debug.h>
#include <drivers/auth/auth_mod.h>
#include <drivers/auth/crypto_mod.h>
#include <drivers/console.h>
#include <drivers/fwu/fwu.h>
#include <lib/bootmarker_capture.h>
#include <lib/extensions/pauth.h>
#include <lib/pmf/pmf.h>
#include <plat/common/platform.h>

#include "bl2_private.h"

#ifdef __aarch64__
#define NEXT_IMAGE	"BL31"
#else
#define NEXT_IMAGE	"BL32"
#endif

#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_REGISTER_SERVICE(bl_svc, PMF_RT_INSTR_SVC_ID,
		BL_TOTAL_IDS, PMF_DUMP_ENABLE);
#endif

/*******************************************************************************
 * The only thing to do in BL2 is to load further images and pass control to
 * next BL. The memory occupied by BL2 will be reclaimed by BL3x stages.
 ******************************************************************************/
void __no_pauth bl2_main(u_register_t arg0, u_register_t arg1, u_register_t arg2,
	       u_register_t arg3)
{
	entry_point_info_t *next_bl_ep_info;

	/* Enable early console if EARLY_CONSOLE flag is enabled */
	plat_setup_early_console();

	/* Perform early platform-specific setup */
	bl2_early_platform_setup2(arg0, arg1, arg2, arg3);

	/* Perform remaining generic architectural setup */
	bl2_arch_setup();

	/* Perform late platform-specific setup */
	bl2_plat_arch_setup();

	if (is_feat_pauth_supported()) {
#if BL2_RUNS_AT_EL3
		pauth_init_enable_el3();
#else
		pauth_init_enable_el1();
#endif
	}

#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_CAPTURE_TIMESTAMP(bl_svc, BL2_ENTRY, PMF_CACHE_MAINT);
#endif

	NOTICE("BL2: %s\n", build_version_string);
	NOTICE("BL2: %s\n", build_message);

#if PSA_FWU_SUPPORT
	fwu_init();
#endif /* PSA_FWU_SUPPORT */

	crypto_mod_init();

	/* Initialize authentication module */
	auth_mod_init();

	/* Initialize the Measured Boot backend */
	bl2_plat_mboot_init();

	if (is_feat_crypto_supported()) {
#if BL2_RUNS_AT_EL3
		disable_fpregs_traps_el3();
#endif
	}

	/* Initialize boot source */
	bl2_plat_preload_setup();

#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_CAPTURE_TIMESTAMP(bl_svc, BL2_AUTH_START, PMF_CACHE_MAINT);
#endif

	/* Load the subsequent bootloader images. */
	next_bl_ep_info = bl2_load_images();

	if (is_feat_crypto_supported()) {
#if BL2_RUNS_AT_EL3
		enable_fpregs_traps_el3();
#endif
	}

#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_CAPTURE_TIMESTAMP(bl_svc, BL2_AUTH_END, PMF_CACHE_MAINT);
#endif


	/* Teardown the Measured Boot backend */
	bl2_plat_mboot_finish();

	crypto_mod_finish();

#if !BL2_RUNS_AT_EL3
#ifndef __aarch64__
	/*
	 * For AArch32 state BL1 and BL2 share the MMU setup.
	 * Given that BL2 does not map BL1 regions, MMU needs
	 * to be disabled in order to go back to BL1.
	 */
	disable_mmu_icache_secure();
#endif /* !__aarch64__ */

	/*
	 * Disable pointer authentication before running next boot image
	 */
	if (is_feat_pauth_supported()) {
		pauth_disable_el1();
	}

#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_CAPTURE_TIMESTAMP(bl_svc, BL2_EXIT, PMF_CACHE_MAINT);
#endif

	console_flush();

	/*
	 * Run next BL image via an SMC to BL1. Information on how to pass
	 * control to the BL32 (if present) and BL33 software images will
	 * be passed to next BL image as an argument.
	 */
	smc(BL1_SMC_RUN_IMAGE, (unsigned long)next_bl_ep_info, 0, 0, 0, 0, 0, 0);
#else /* if BL2_RUNS_AT_EL3 */

	NOTICE("BL2: Booting " NEXT_IMAGE "\n");
	print_entry_point_info(next_bl_ep_info);
#if ENABLE_RUNTIME_INSTRUMENTATION
	PMF_CAPTURE_TIMESTAMP(bl_svc, BL2_EXIT, PMF_CACHE_MAINT);
#endif
	console_flush();

	/*
	 * Disable pointer authentication before running next boot image
	 */
	if (is_feat_pauth_supported()) {
		pauth_disable_el3();
	}

	bl2_run_next_image(next_bl_ep_info);
#endif /* BL2_RUNS_AT_EL3 */
}