uboot 【board_init_r】

void board_init_r(gd_t *new_gd, ulong dest_addr)
{
#ifdef CONFIG_NEEDS_MANUAL_RELOC
	int i;
#endif

#if !defined(CONFIG_X86) && !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
	gd = new_gd;
#endif

#ifdef CONFIG_NEEDS_MANUAL_RELOC
	for (i = 0; i < ARRAY_SIZE(init_sequence_r); i++)
		init_sequence_r[i] += gd->reloc_off;
#endif
    //按照init_sequence_r顺序进行初始化，包括控制台，nor flash,nand flash,网口等，最后等待用户输入或者启动内核
	if (initcall_run_list(init_sequence_r))
		hang();

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

board_init_r：

        1.按照init_sequence_r顺序进行初始化，包括控制台，nor flash,nand flash,网口等，最后等待用户输入或者启动内核

/*
 * Over time we hope to remove these functions with code fragments and
 * stub funtcions, and instead call the relevant function directly.
 *
 * We also 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?
 */
init_fnc_t init_sequence_r[] = {
	initr_trace,
	initr_reloc,
	/* TODO: could x86/PPC have this also perhaps? */
#ifdef CONFIG_ARM
	initr_caches,
#endif
    //更新重定位后的gd
	initr_reloc_global_data,
#if defined(CONFIG_SYS_INIT_RAM_LOCK) && defined(CONFIG_E500)
	initr_unlock_ram_in_cache,
#endif
	initr_barrier,
	initr_malloc,
#ifdef CONFIG_SYS_NONCACHED_MEMORY
	initr_noncached,
#endif
	bootstage_relocate,
#ifdef CONFIG_DM
	initr_dm,
#endif
#ifdef CONFIG_ARM
	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
	stdio_init_tables,
	initr_serial,
    //表明现在已运行在内存中
	initr_announce,
	INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_PPC
	initr_trap,
#endif
#ifdef CONFIG_ADDR_MAP
	initr_addr_map,
#endif
#if defined(CONFIG_BOARD_EARLY_INIT_R)
	board_early_init_r,
#endif
	INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_LOGBUFFER
	initr_logbuffer,
#endif
#ifdef CONFIG_POST
	initr_post_backlog,
#endif
	INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_SYS_DELAYED_ICACHE
	initr_icache_enable,
#endif
#if defined(CONFIG_PCI) && defined(CONFIG_SYS_EARLY_PCI_INIT)
	/*
	 * Do early PCI configuration _before_ the flash gets initialised,
	 * because PCU ressources are crucial for flash access on some boards.
	 */
	initr_pci,
#endif
#ifdef CONFIG_WINBOND_83C553
	initr_w83c553f,
#endif
#ifdef CONFIG_ARCH_EARLY_INIT_R
	arch_early_init_r,
#endif
	power_init_board,
#ifndef CONFIG_SYS_NO_FLASH
    //初始化nor flash
	initr_flash,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PPC)
	/* initialize higher level parts of CPU like time base and timers */
	cpu_init_r,
#endif
#ifdef CONFIG_PPC
	initr_spi,
#endif
#if defined(CONFIG_X86) && defined(CONFIG_SPI)
	init_func_spi,
#endif
#ifdef CONFIG_CMD_NAND
    //初始化nand flash
	initr_nand,
#endif
#ifdef CONFIG_CMD_ONENAND
	initr_onenand,
#endif
#ifdef CONFIG_GENERIC_MMC
	initr_mmc,
#endif
#ifdef CONFIG_HAS_DATAFLASH
	initr_dataflash,
#endif
    //初始化环境变量
	initr_env,
	INIT_FUNC_WATCHDOG_RESET
	initr_secondary_cpu,
#ifdef CONFIG_SC3
	initr_sc3_read_eeprom,
#endif
#if defined(CONFIG_ID_EEPROM) || defined(CONFIG_SYS_I2C_MAC_OFFSET)
	mac_read_from_eeprom,
#endif
	INIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PCI) && !defined(CONFIG_SYS_EARLY_PCI_INIT)
	/*
	 * Do pci configuration
	 */
	initr_pci,
#endif
	stdio_add_devices,
	initr_jumptable,
#ifdef CONFIG_API
	initr_api,
#endif
    //初始化控制台
	console_init_r,		/* fully init console as a device */
#ifdef CONFIG_DISPLAY_BOARDINFO_LATE
	show_model_r,
#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_ARM)
	initr_enable_interrupts,
#endif
#ifdef CONFIG_X86
	timer_init,		/* initialize timer */
#endif
#if defined(CONFIG_STATUS_LED) && defined(STATUS_LED_BOOT)
	initr_status_led,
#endif
	/* PPC has a udelay(20) here dating from 2002. Why? */
#ifdef CONFIG_CMD_NET
    //获取mac地址
	initr_ethaddr,
#endif
#ifdef CONFIG_BOARD_LATE_INIT
	board_late_init,
#endif
#ifdef CONFIG_CMD_SCSI
	INIT_FUNC_WATCHDOG_RESET
	initr_scsi,
#endif
#ifdef CONFIG_CMD_DOC
	INIT_FUNC_WATCHDOG_RESET
	initr_doc,
#endif
#ifdef CONFIG_BITBANGMII
	initr_bbmii,
#endif
#ifdef CONFIG_CMD_NET
	INIT_FUNC_WATCHDOG_RESET
   //初始化网口
	initr_net,
#endif
#ifdef CONFIG_POST
	initr_post,
#endif
#if defined(CONFIG_CMD_PCMCIA) && !defined(CONFIG_CMD_IDE)
	initr_pcmcia,
#endif
#if defined(CONFIG_CMD_IDE)
	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
	initr_bedbug,
#endif
#if defined(CONFIG_PRAM) || defined(CONFIG_LOGBUFFER)
	initr_mem,
#endif
#ifdef CONFIG_PS2KBD
	initr_kbd,
#endif
    //等到用户输入或启动引导内核
	run_main_loop,
};

init_sequence_r：

        1.initr_reloc_global_data：更新重定位后的gd

        2.initr_announce：表明现在已运行在内存中

        3.initr_flash：初始化nor flash，包括基地址，大小，数据为宽度，flash类型

        4.initr_nand：初始化nand flash，包括基地址，大小，数据为宽度，flash类型,page大小，block大小

        5.initr_env：初始化环境变量，现在flash已经初始化完成，可以将真正的环境变量拷贝到内存中

        6.console_init_r：初始化控制台

        7.initr_ethaddr：获取mac地址

        8.initr_net：初始化网口，包括phy地址，接口类型

        9.run_main_loop：等到用户输入或启动引导内核