uboot（四）—— board_init_r

目录

一、crt0_64.S最后部分

二、board_init_r

三、init_sequence_r[] 函数数组

---

一、crt0_64.S最后部分

清bss段，然后执行board_init_r

/*
 * Clear BSS section ，清除bss段
 */
	ldr	x0, =__bss_start		/* this is auto-relocated! */
	ldr	x1, =__bss_end			/* this is auto-relocated! */
clear_loop:
	str	xzr, [x0], #8
	cmp	x0, x1
	b.lo	clear_loop

	/* call board_init_r(gd_t *id, ulong dest_addr) */
	mov	x0, x18				/* gd_t */
	ldr	x1, [x18, #GD_RELOCADDR]	/* dest_addr */
	b	board_init_r			/* PC relative jump */

	/* NOTREACHED - board_init_r() does not return */
#endif

二、board_init_r

位置：u-boot-2022.01\common\Board_r.c
和board_init_f 一样循环执行多个函数

void board_init_r(gd_t *new_gd, ulong dest_addr)
{
	/*
	 * Set up the new global data pointer. So far only x86 does this
	 * here.
	 * TODO([email protected]): Consider doing this for all archs, or
	 * dropping the new_gd parameter.
	 */

	gd->flags &= ~GD_FLG_LOG_READY;

	if (initcall_run_list(init_sequence_r))
		hang();

	/* NOTREACHED - run_main_loop() does not return */
	hang();
}

三、init_sequence_r[] 函数数组

主要用于初始化各类外设信息

/*
 * We hope to remove most of the driver-related init and do it if/when
 * the driver is later used.
 *
 * TODO: perhaps reset the watchdog in the initcall function after each call?
 */
static init_fnc_t init_sequence_r[] = {
	initr_trace,
	initr_reloc,
	/* TODO: could x86/PPC have this also perhaps? */
#if defined(CONFIG_ARM) || defined(CONFIG_RISCV)
	initr_caches,
	/* Note: For Freescale LS2 SoCs, new MMU table is created in DDR.
	 *	 A temporary mapping of IFC high region is since removed,
	 *	 so environmental variables in NOR flash is not available
	 *	 until board_init() is called below to remap IFC to high
	 *	 region.
	 */
#endif
	initr_reloc_global_data,
#if defined(CONFIG_SYS_INIT_RAM_LOCK) && defined(CONFIG_E500)
	initr_unlock_ram_in_cache,
#endif
	initr_barrier,
	initr_malloc,
	log_init,
	initr_bootstage,	/* Needs malloc() but has its own timer */
#if defined(CONFIG_CONSOLE_RECORD)
	console_record_init,
#endif
#ifdef CONFIG_SYS_NONCACHED_MEMORY
	noncached_init,
#endif
	initr_of_live,
#ifdef CONFIG_DM
	initr_dm,
#endif
#ifdef CONFIG_ADDR_MAP
	initr_addr_map,
#endif
#if defined(CONFIG_ARM) || defined(CONFIG_NDS32) || defined(CONFIG_RISCV) || \
	defined(CONFIG_SANDBOX)
	board_init,	/* Setup chipselects */
#endif
	/*
	 * TODO: printing of the clock inforamtion of the board is now
	 * implemented as part of bdinfo command. Currently only support for
	 * davinci SOC's is added. Remove this check once all the board
	 * implement this.
	 */
#ifdef CONFIG_CLOCKS
	set_cpu_clk_info, /* Setup clock information */
#endif
#ifdef CONFIG_EFI_LOADER
	efi_memory_init,
#endif
	initr_binman,
#ifdef CONFIG_FSP_VERSION2
	arch_fsp_init_r,
#endif
	initr_dm_devices,
	stdio_init_tables,
	serial_initialize,
	initr_announce,
#if CONFIG_IS_ENABLED(WDT)
	initr_watchdog,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_NEEDS_MANUAL_RELOC) && defined(CONFIG_BLOCK_CACHE)
	blkcache_init,
#endif
#ifdef CONFIG_NEEDS_MANUAL_RELOC
	initr_manual_reloc_cmdtable,
#endif
	arch_initr_trap,
#if defined(CONFIG_BOARD_EARLY_INIT_R)
	board_early_init_r,
#endif
	INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_POST
	post_output_backlog,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PCI_INIT_R) && defined(CONFIG_SYS_EARLY_PCI_INIT)
	/*
	 * Do early PCI configuration _before_ the flash gets initialised,
	 * because PCU resources are crucial for flash access on some boards.
	 */
	pci_init,
#endif
#ifdef CONFIG_ARCH_EARLY_INIT_R
	arch_early_init_r,
#endif
	power_init_board,
#ifdef CONFIG_MTD_NOR_FLASH
	initr_flash,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_X86)
	/* initialize higher level parts of CPU like time base and timers */
	cpu_init_r,
#endif
#ifdef CONFIG_CMD_NAND
	initr_nand,
#endif
#ifdef CONFIG_CMD_ONENAND
	initr_onenand,
#endif
#ifdef CONFIG_MMC
	initr_mmc,
#endif
#ifdef CONFIG_XEN
	xen_init,
#endif
#ifdef CONFIG_PVBLOCK
	initr_pvblock,
#endif
	initr_env,
#ifdef CONFIG_SYS_BOOTPARAMS_LEN
	initr_malloc_bootparams,
#endif
	INIT_FUNC_WATCHDOG_RESET
	cpu_secondary_init_r,
#if defined(CONFIG_ID_EEPROM)
	mac_read_from_eeprom,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PCI_INIT_R) && !defined(CONFIG_SYS_EARLY_PCI_INIT)
	/*
	 * Do pci configuration
	 */
	pci_init,
#endif
	stdio_add_devices,
	jumptable_init,
#ifdef CONFIG_API
	api_init,
#endif
	console_init_r,		/* fully init console as a device */
#ifdef CONFIG_DISPLAY_BOARDINFO_LATE
	console_announce_r,
	show_board_info,
#endif
#ifdef CONFIG_ARCH_MISC_INIT
	arch_misc_init,		/* miscellaneous arch-dependent init */
#endif
#ifdef CONFIG_MISC_INIT_R
	misc_init_r,		/* miscellaneous platform-dependent init */
#endif
	INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_CMD_KGDB
	initr_kgdb,
#endif
	interrupt_init,
#if defined(CONFIG_MICROBLAZE) || defined(CONFIG_M68K)
	timer_init,		/* initialize timer */
#endif
#if defined(CONFIG_LED_STATUS)
	initr_status_led,
#endif
	/* PPC has a udelay(20) here dating from 2002. Why? */
#ifdef CONFIG_CMD_NET
	initr_ethaddr,
#endif
#if defined(CONFIG_GPIO_HOG)
	gpio_hog_probe_all,
#endif
#ifdef CONFIG_BOARD_LATE_INIT
	board_late_init,
#endif
#if defined(CONFIG_SCSI) && !defined(CONFIG_DM_SCSI)
	INIT_FUNC_WATCHDOG_RESET
	initr_scsi,
#endif
#ifdef CONFIG_BITBANGMII
	bb_miiphy_init,
#endif
#ifdef CONFIG_PCI_ENDPOINT
	pci_ep_init,
#endif
#ifdef CONFIG_CMD_NET
	INIT_FUNC_WATCHDOG_RESET
	initr_net,
#endif
#ifdef CONFIG_POST
	initr_post,
#endif
#if defined(CONFIG_IDE) && !defined(CONFIG_BLK)
	initr_ide,
#endif
#ifdef CONFIG_LAST_STAGE_INIT
	INIT_FUNC_WATCHDOG_RESET
	/*
	 * Some parts can be only initialized if all others (like
	 * Interrupts) are up and running (i.e. the PC-style ISA
	 * keyboard).
	 */
	last_stage_init,
#endif
#ifdef CONFIG_CMD_BEDBUG
	INIT_FUNC_WATCHDOG_RESET
	bedbug_init,
#endif
#if defined(CONFIG_PRAM)
	initr_mem,
#endif
#ifdef CONFIG_EFI_SETUP_EARLY
	(init_fnc_t)efi_init_obj_list,
#endif
	run_main_loop,
};

• initr_trace：什么都没做
• initr_reloc：设置flag标志，表示重定位完成
• initr_caches：使能高速缓存
• initr_reloc_global_data：更新重定位后的gd
• initr_barrier：什么都没做
• initr_malloc：初始化malloc内存区域

  xw_r: board_r.c:initr_malloc:malloc_start = 07b3c000

• log_init：未定义，什么都没做，/include/log.h

  static inline int log_init(void)
  {
  	return 0;
  }

• initr_bootstage：初始化 bootstage，显示当前运行进度
• initr_dm：初始化设备模型
• board_init：硬件板卡级的初始化操作
  位置u-boot-2022.01/board/raspberrypi/rpi/rpi.c

      int board_init(void)
  481 {
  482 #ifdef CONFIG_HW_WATCHDOG
  483         hw_watchdog_init();
  484 #endif
  485 
  486         get_board_revision();
  487 
  488         gd->bd->bi_boot_params = 0x100;//这个内存地址就被分配用来做内核传参
  489 
  490         return bcm2835_power_on_module(BCM2835_MBOX_POWER_DEVID_USB_HCD);
  491 }
  
  xw_r: rpi.c:board_init:gd->bd->bi_arch_number = 00000000 //机器码
  xw_r: rpi.c:board_init:gd->bd->bi_boot_params = 00000100 //传参地址

• efi_memory_init：EFI引导相关
• initr_binman：啥也没做
• initr_dm_devices：初始化设备驱动
• stdio_init_tables：初始化了一个双向循环链表
• serial_initialize：注册串行端口设备
• initr_announce：打印出运行调试信息
• initr_watchdog：初始化看门狗
• power_init_board：初始化电源芯片
• initr_mmc：初始化mmc，打印

  MMC:   mmc@7e202000: 0, sdhci@7e300000: 1

• initr_env：刚开始sd卡里面是没有环境变量的，第一次启动uboot，环境变量保存到sd卡
  初始化环境变量，打印出

  Loading Environment from FAT... OK

• //initr_malloc_bootparams：给bi_boot_params分配内存（内核传参地址），没执行
• cpu_secondary_init_r：空函数，初始化其他 CPU 核
• stdio_add_devices：各种输入输出设备的初始化，添加stdio设备到设备表中
• jumptable_init：初始化跳转表，使用malloc为跳转表分配内存
  本身是一个函数指针数组，里面记录了很多函数的函数名。面向对象
• console_init_r：将stdin，stdout，stderr与具体的终端设备绑定起来，并打印
  控制台初始化，打印in，out
• misc_init_r：从设备树获取各种板子信息
• interrupt_init：架构相关函数，用于中断相关的初始化操作
• initr_ethaddr：获取mac地址
• initr_net：初始化网口，包括phy地址，接口类型
• //initr_mem：会导出Linux的可用内存大小
• run_main_loop：大循环main_loop，启动内核或者处理用户输入的命令