示例#1
0
/*******************************************************************************
 * The only thing to do in BL2 is to load further images and pass control to
 * BL31. The memory occupied by BL2 will be reclaimed by BL3_x stages. BL2 runs
 * entirely in S-EL1. Since arm standard c libraries are not PIC, printf et al
 * are not available. We rely on assertions to signal error conditions
 ******************************************************************************/
void bl2_main(void)
{
	meminfo *bl2_tzram_layout;
	bl31_args *bl2_to_bl31_args;
	unsigned long bl31_base, bl32_base = 0, bl33_base, el_status;
	unsigned int bl2_load, bl31_load, mode;

	/* Perform remaining generic architectural setup in S-El1 */
	bl2_arch_setup();

	/* Perform platform setup in BL1 */
	bl2_platform_setup();

	printf("BL2 %s\n\r", build_message);

	/* Find out how much free trusted ram remains after BL2 load */
	bl2_tzram_layout = bl2_plat_sec_mem_layout();

	/*
	 * Load BL31. BL1 tells BL2 whether it has been TOP or BOTTOM loaded.
	 * To avoid fragmentation of trusted SRAM memory, BL31 is always
	 * loaded opposite to BL2. This allows BL31 to reclaim BL2 memory
	 * while maintaining its free space in one contiguous chunk.
	 */
	bl2_load = bl2_tzram_layout->attr & LOAD_MASK;
	assert((bl2_load == TOP_LOAD) || (bl2_load == BOT_LOAD));
	bl31_load = (bl2_load == TOP_LOAD) ? BOT_LOAD : TOP_LOAD;
	bl31_base = load_image(bl2_tzram_layout, BL31_IMAGE_NAME,
	                       bl31_load, BL31_BASE);

	/* Assert if it has not been possible to load BL31 */
	if (bl31_base == 0) {
		ERROR("Failed to load BL3-1.\n");
		panic();
	}

	/*
	 * Get a pointer to the memory the platform has set aside to pass
	 * information to BL31.
	 */
	bl2_to_bl31_args = bl2_get_bl31_args_ptr();

	/*
	 * Load the BL32 image if there's one. It is upto to platform
	 * to specify where BL32 should be loaded if it exists. It
	 * could create space in the secure sram or point to a
	 * completely different memory. A zero size indicates that the
	 * platform does not want to load a BL32 image.
	 */
	if (bl2_to_bl31_args->bl32_meminfo.total_size)
		bl32_base = load_image(&bl2_to_bl31_args->bl32_meminfo,
				       BL32_IMAGE_NAME,
				       bl2_to_bl31_args->bl32_meminfo.attr &
				       LOAD_MASK,
				       BL32_BASE);

	/*
	 * Create a new layout of memory for BL31 as seen by BL2. This
	 * will gobble up all the BL2 memory.
	 */
	init_bl31_mem_layout(bl2_tzram_layout,
			     &bl2_to_bl31_args->bl31_meminfo,
			     bl31_load);

	/* Load the BL33 image in non-secure memory provided by the platform */
	bl33_base = load_image(&bl2_to_bl31_args->bl33_meminfo,
			       BL33_IMAGE_NAME,
			       BOT_LOAD,
			       plat_get_ns_image_entrypoint());
	/* Halt if failed to load normal world firmware. */
	if (bl33_base == 0) {
		ERROR("Failed to load BL3-3.\n");
		panic();
	}

	/*
	 * BL2 also needs to tell BL31 where the non-trusted software image
	 * is located.
	 */
	bl2_to_bl31_args->bl33_image_info.entrypoint = bl33_base;

	/* Figure out what mode we enter the non-secure world in */
	el_status = read_id_aa64pfr0_el1() >> ID_AA64PFR0_EL2_SHIFT;
	el_status &= ID_AA64PFR0_ELX_MASK;

	if (el_status)
		mode = MODE_EL2;
	else
		mode = MODE_EL1;

	/*
	 * TODO: Consider the possibility of specifying the SPSR in
	 * the FIP ToC and allowing the platform to have a say as
	 * well.
	 */
	bl2_to_bl31_args->bl33_image_info.spsr =
		make_spsr(mode, MODE_SP_ELX, MODE_RW_64);
	bl2_to_bl31_args->bl33_image_info.security_state = NON_SECURE;

	if (bl32_base) {
		/* Fill BL32 image info */
		bl2_to_bl31_args->bl32_image_info.entrypoint = bl32_base;
		bl2_to_bl31_args->bl32_image_info.security_state = SECURE;

		/*
		 * The Secure Payload Dispatcher service is responsible for
		 * setting the SPSR prior to entry into the BL32 image.
		 */
		bl2_to_bl31_args->bl32_image_info.spsr = 0;
	}

	/* Flush the entire BL31 args buffer */
	flush_dcache_range((unsigned long) bl2_to_bl31_args,
			   sizeof(*bl2_to_bl31_args));

	/*
	 * Run BL31 via an SMC to BL1. Information on how to pass control to
	 * the BL32 (if present) and BL33 software images will be passed to
	 * BL31 as an argument.
	 */
	run_image(bl31_base,
		  make_spsr(MODE_EL3, MODE_SP_ELX, MODE_RW_64),
		  SECURE,
		  (void *) bl2_to_bl31_args,
		  NULL);
}
/*******************************************************************************
 * 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)
{
	unsigned long sctlr_el3 = read_sctlr();
	unsigned long bl2_base;
	unsigned int load_type = TOP_LOAD, spsr;
	meminfo *bl1_tzram_layout;
	meminfo *bl2_tzram_layout = 0x0;

	/*
	 * 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();

	/* Announce our arrival */
	printf(FIRMWARE_WELCOME_STR);
	printf("Built : %s, %s\n\r", __TIME__, __DATE__);

	/*
	 * Find out how much free trusted ram remains after BL1 load
	 * & load the BL2 image at its top
	 */
	bl1_tzram_layout = bl1_plat_sec_mem_layout();
	bl2_base = load_image(bl1_tzram_layout,
			      (const char *) BL2_IMAGE_NAME,
			      load_type, BL2_BASE);

	/*
	 * 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 *) bl1_tzram_layout->free_base;
	init_bl2_mem_layout(bl1_tzram_layout,
			    bl2_tzram_layout,
			    load_type,
			    bl2_base);

	if (bl2_base) {
		bl1_arch_next_el_setup();
		spsr = make_spsr(MODE_EL1, MODE_SP_ELX, MODE_RW_64);
		printf("Booting trusted firmware boot loader stage 2\n\r");
#if DEBUG
		printf("BL2 address = 0x%llx \n\r", (unsigned long long) bl2_base);
		printf("BL2 cpsr = 0x%x \n\r", spsr);
		printf("BL2 memory layout address = 0x%llx \n\r",
		       (unsigned long long) bl2_tzram_layout);
#endif
		run_image(bl2_base, spsr, SECURE, bl2_tzram_layout, 0);
	}

	/*
	 * TODO: print failure to load BL2 but also add a tzwdog timer
	 * which will reset the system eventually.
	 */
	printf("Failed to load boot loader stage 2 (BL2) firmware.\n\r");
	return;
}