? ? ? ? 本文主要探討210的uboot啟動的第二階段，主要函數(shù)為start_armboot。

uboot
? ? 一階段初始化SoC內(nèi)部部件(看門狗、時鐘等),初始化DDR,重定位
? ? 二階段初始化其余硬件(iNand、網(wǎng)卡芯片···)以及命令、環(huán)境變量等···
? ? 啟動打印硬件信息,進入bootdelay,讀秒完后執(zhí)行bootcmd啟動內(nèi)核或打斷讀秒進入命名狀態(tài)

? ? ?一階段為匯編,在SRAM中,主要在SoC內(nèi)部,二階段為C階,在DRAM中,主要在Board內(nèi)部

start_armboot(函數(shù)在uboot/lib_arm/board.c(444~908))

?? ?全局變量

? ? ????????全局變量定義

#define DECLARE_GLOBAL_DATA_PTR ? ? register volatile gd_t *gd asm ("r8")

?? ?typedef?? ?struct?? ?global_data {bd_t?? ??? ?*bd;unsigned long?? ?flags;unsigned long?? ?baudrate;unsigned long?? ?have_console;?? ?/* serial_init() was called */unsigned long?? ?reloc_off;?? ?/* Relocation Offset */unsigned long?? ?env_addr;?? ?/* Address ?of Environment struct */unsigned long?? ?env_valid;?? ?/* Checksum of Environment valid? */unsigned long?? ?fb_base;?? ?/* base address of frame buffer */#ifdef CONFIG_VFDunsigned char?? ?vfd_type;?? ?/* display type */#endif#if 0unsigned long?? ?cpu_clk;?? ?/* CPU clock in Hz!?? ??? ?*/unsigned long?? ?bus_clk;phys_size_t?? ?ram_size;?? ?/* RAM size */unsigned long?? ?reset_status;?? ?/* reset status register at boot */#endifvoid?? ??? ?**jt;?? ??? ?/* jump table */} gd_t;

?? ?????????????????定義全局變量gd到寄存器r8中,為gd_t類型變量指針
?? ?????????????????gd_t定義在include/asm-arm/global_data.h中
?? ?????????????????gd_t中定義全局變量,其中bd_t結(jié)構(gòu)體包含硬件參數(shù)(波特率,IP,mac,機器碼,啟動參數(shù),環(huán)境變量,DDR,網(wǎng)卡)

?? ?????????全局變量內(nèi)存分配?? ?

#ifdef CONFIG_MEMORY_UPPER_CODE /* by scsuh */ulong gd_base;gd_base = CFG_UBOOT_BASE + CFG_UBOOT_SIZE - CFG_MALLOC_LEN - CFG_STACK_SIZE - sizeof(gd_t);#ifdef CONFIG_USE_IRQgd_base -= (CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ);#endifgd = (gd_t*)gd_base;#elsegd = (gd_t*)(_armboot_start - CFG_MALLOC_LEN - sizeof(gd_t));#endifgd_base = CFG_UBOOT_BASE + CFG_UBOOT_SIZE - CFG_MALLOC_LEN - CFG_STACK_SIZE - sizeof(gd_t);gd = (gd_t*)gd_base;

?? ?#define CFG_UBOOT_BASE?? ??? ?0xc3e00000 ? ??? ??? ??? ?#define CFG_UBOOT_SIZE?? ??? ?(2*1024*1024) ?? ??? ??? ?#define CFG_MALLOC_LEN?? ??? ?(CFG_ENV_SIZE + 896*1024) ?? ?#define CFG_ENV_SIZE?? ??? ?  0x4000    //(16字節(jié))#define CFG_STACK_SIZE?? ??? ?512*1024?? 

??? ??? ?
? ? ? ? ? ? ? ? ? ? uboot?? ??? ?CFG_UBOOT_BASE(2MB)
?? ?????????????????堆? ? ? ? ? ? ?CFG_MALLOC_LEN(912KB)
?? ?????????????????棧? ? ? ? ? ? ?CFG_STACK_SIZE(512KB)
?? ?????????????????gd? ? ? ? ? ? ?sizeof(gd_t)(36字節(jié))
?? ?????????????????bd? ? ? ? ? ? ?sizeof(bd_t)(44字節(jié)左右)

?? ?????????????????全局變量內(nèi)存清空?

? ?__asm__ __volatile__("": : :"memory");memset ((void*)gd, 0, sizeof (gd_t));gd->bd = (bd_t*)((char*)gd - sizeof(bd_t));memset (gd->bd, 0, sizeof (bd_t));monitor_flash_len = _bss_start - _armboot_start;

board級硬件初始化

?? ?init_fnc_t **init_fnc_ptr;typedef int (init_fnc_t) (void); //函數(shù)類型

?? ?????????init_fnc_ptr是二重函數(shù)指針,用來指向函數(shù)指針數(shù)組

? ?for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {if ((*init_fnc_ptr)() != 0) {hang ();}}

??

?init_fnc_t *init_sequence[] = {cpu_init,?? ??? ?/* basic cpu dependent setup */#if defined(CONFIG_SKIP_RELOCATE_UBOOT)reloc_init,?? ??? ?/* Set the relocation done flag, mustdo this AFTER cpu_init(), but as soonas possible */#endifboard_init,?? ??? ?/* basic board dependent setup */interrupt_init,?? ??? ?/* set up exceptions */env_init,?? ??? ?/* initialize environment */init_baudrate,?? ??? ?/* initialze baudrate settings */serial_init,?? ??? ?/* serial communications setup */console_init_f,?? ??? ?/* stage 1 init of console */display_banner,?? ??? ?/* say that we are here */#if defined(CONFIG_DISPLAY_CPUINFO)print_cpuinfo,?? ??? ?/* display cpu info (and speed) */#endif#if defined(CONFIG_DISPLAY_BOARDINFO)checkboard,?? ??? ?/* display board info */#endif#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)init_func_i2c,#endifdram_init,?? ??? ?/* configure available RAM banks */display_dram_config,NULL,};

?? ?????????cpu_init

?? ?int cpu_init (void){/** setup up stacks if necessary*/#ifdef CONFIG_USE_IRQIRQ_STACK_START = _armboot_start - CFG_MALLOC_LEN - CFG_GBL_DATA_SIZE - 4;FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;#endifreturn 0;}

?? ?????????????????空函數(shù),cpu初始化在一階段cpu_init_crit函數(shù)中完成(匯編)

?? ?
?? ?????????board_init(uboot/board/samsung/x210/x210.c)

?? ?int board_init(void){DECLARE_GLOBAL_DATA_PTR;#ifdef CONFIG_DRIVER_SMC911Xsmc9115_pre_init();#endif#ifdef CONFIG_DRIVER_DM9000dm9000_pre_init();#endifgd->bd->bi_arch_number = MACH_TYPE;gd->bd->bi_boot_params = (PHYS_SDRAM_1+0x100);return 0;}

?? ?static void dm9000_pre_init(void){unsigned int tmp;#if defined(DM9000_16BIT_DATA)SROM_BW_REG &= ~(0xf << 4);SROM_BW_REG |= (1<<7) | (1<<6) | (1<<5) | (1<<4);#elseSROM_BW_REG &= ~(0xf << 4);SROM_BW_REG |= (0<<6) | (0<<5) | (0<<4);#endifSROM_BC1_REG = ((0<<28)|(1<<24)|(5<<16)|(1<<12)|(4<<8)|(6<<4)|(0<<0));//uboot//SROM_BC1_REG = ((0<<28)|(0<<24)|(5<<16)|(0<<12)|(0<<8)|(0<<4)|(0<<0));//kerneltmp = MP01CON_REG;tmp &=~(0xf<<4);tmp |=(2<<4);MP01CON_REG = tmp;}

?? ?????????dm9000_pre_init函數(shù)為網(wǎng)卡初始化(GPIO和端口配置非驅(qū)動),gd->bd->bi_arch_number定義機器碼,gd->bd->bi_boot_params為內(nèi)核啟動傳遞參數(shù)內(nèi)存地址(0x30000100)

??

 ?gd->bd->bi_boot_params = (PHYS_SDRAM_1+0x100);

?? ?

#define CONFIG_NR_DRAM_BANKS ? ?2 ? ? ? ? ?/* we have 2 bank of DRAM */#define SDRAM_BANK_SIZE ? ? ? ? 0x10000000 //256 ? /*0x20000000*/ ? ?/* 512 MB */#define PHYS_SDRAM_1 ? ? ? ? ? ?MEMORY_BASE_ADDRESS /* SDRAM Bank #1 */#define PHYS_SDRAM_1_SIZE ? ? ? SDRAM_BANK_SIZE#define PHYS_SDRAM_2 ? ? ? ? ? ?MEMORY_BASE_ADDRESS2 /* SDRAM Bank #2 */#define PHYS_SDRAM_2_SIZE ? ? ? SDRAM_BANK_SIZE

?#define CFG_FLASH_BASE?? ??? ?0x80000000

#define MEMORY_BASE_ADDRESS?? ?0x30000000

?? ?????????????????一階段匯編lowlevel_init初始化DDR為硬件初始化(gpio),DDR可工作,此處為DDR屬性配置、地址初始化
?? ?????????????????x210_sd.h(496~501)宏定義DDR參數(shù)(內(nèi)存?zhèn)€數(shù),內(nèi)存起始地址,內(nèi)存長度)

?? ?????????

????????????????interrupt_init

?? ?int interrupt_init(void){S5PC11X_TIMERS *const timers = S5PC11X_GetBase_TIMERS();/* use PWM Timer 4 because it has no output *//* prescaler for Timer 4 is 16 */timers->TCFG0 = 0x0f00;if (timer_load_val == 0) {/** for 10 ms clock period @ PCLK with 4 bit divider = 1/2* (default) and prescaler = 16. Should be 10390* @33.25MHz and ?@ 66 MHz*/timer_load_val = get_PCLK() / (16 * 100);}/* load value for 10 ms timeout */lastdec = timers->TCNTB4 = timer_load_val;/* auto load, manual update of Timer 4 */timers->TCON = (timers->TCON & ~0x00700000) | TCON_4_AUTO | TCON_4_UPDATE;/* auto load, start Timer 4 */timers->TCON = (timers->TCON & ~0x00700000) | TCON_4_AUTO | COUNT_4_ON;timestamp = 0;return (0);}

?? ?????????????????初始化定時器(Timer4),210有5個PWM定時器,Timer0-timer3對應(yīng)PWM信號輸出引腳,Timer4無引腳用來做計時

?? ?????????env_init

?? ?int env_init(void){#if defined(ENV_IS_EMBEDDED)ulong total;int crc1_ok = 0, crc2_ok = 0;env_t *tmp_env1, *tmp_env2;total = CFG_ENV_SIZE;tmp_env1 = env_ptr;tmp_env2 = (env_t *)((ulong)env_ptr + CFG_ENV_SIZE);crc1_ok = (crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc);crc2_ok = (crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc);if (!crc1_ok && !crc2_ok)gd->env_valid = 0;else if(crc1_ok && !crc2_ok)gd->env_valid = 1;else if(!crc1_ok && crc2_ok)gd->env_valid = 2;else {/* both ok - check serial */if(tmp_env1->flags == 255 && tmp_env2->flags == 0)gd->env_valid = 2;else if(tmp_env2->flags == 255 && tmp_env1->flags == 0)gd->env_valid = 1;else if(tmp_env1->flags > tmp_env2->flags)gd->env_valid = 1;else if(tmp_env2->flags > tmp_env1->flags)gd->env_valid = 2;else /* flags are equal - almost impossible */gd->env_valid = 1;}if (gd->env_valid == 1)env_ptr = tmp_env1;else if (gd->env_valid == 2)env_ptr = tmp_env2;#else /* ENV_IS_EMBEDDED */gd->env_addr ?= (ulong)&default_environment[0];gd->env_valid = 1;#endif /* ENV_IS_EMBEDDED */return (0);}

?? ?????????????????環(huán)境變量初始化,開發(fā)板可能包含不同啟動介質(zhì)(norflash、nandflash、inand、sd卡·····),故env的存取需要支持多種存儲方式,210使用的為inand(env_movi.c)
?? ?????????????????函數(shù)有無環(huán)境變量(無),start_armboot函數(shù)(776)調(diào)用env_relocate將環(huán)境變量從SD卡重定位到DDR,重定位從SD卡中讀取

?? ?/* initialize environment */env_relocate ();

?? ?????????init_baudrate
?? ?

static int init_baudrate (void){char tmp[64];?? ?/* long enough for environment variables */int i = getenv_r ("baudrate", tmp, sizeof (tmp));gd->bd->bi_baudrate = gd->baudrate = (i > 0)? (int) simple_strtoul (tmp, NULL, 10): CONFIG_BAUDRATE;return (0);}int getenv_r (char *name, char *buf, unsigned len){int i, nxt;for (i=0; env_get_char(i) != '\0'; i=nxt+1) {int val, n;for (nxt=i; env_get_char(nxt) != '\0'; ++nxt) {if (nxt >= CFG_ENV_SIZE) {return (-1);}}if ((val=envmatch((uchar *)name, i)) < 0)continue;/* found; copy out */n = 0;while ((len > n++) && (*buf++ = env_get_char(val++)) != '\0');if (len == n)*buf = '\0';return (n);}return (-1);}

?? ?????????????????初始化串口通信的波特率,getenv_r函數(shù)讀取環(huán)境變量值,讀取環(huán)境變量值為字符串類型在轉(zhuǎn)成相應(yīng)類型(simple_strtoul將字符串轉(zhuǎn)int)
?? ?????????????????讀取環(huán)境變量中波特率值(gd->baudrate,gd->bd->bi_baudrate),若沒有則在x210_sd.h中CONFIG_BAUDRATE值作為波特率(環(huán)境變量優(yōu)先級高)

?? ?

????????serial_init?? ?

int serial_init(void){serial_setbrg();return (0);}空函數(shù),一階段匯編lowlevel_init中uart_asm_init初始化串口console_init_fint console_init_f (void){gd->have_console = 1;#ifdef CONFIG_SILENT_CONSOLEif (getenv("silent") != NULL)gd->flags |= GD_FLG_SILENT;#endifreturn (0);}

?? ?????????????????console_init_f是console(控制臺)一階段初始化

?? ?????????display_banner

?static int display_banner (void){printf ("\n\n%s\n\n", version_string);debug ("U-Boot code: %08lX -> %08lX ?BSS: -> %08lX\n",_armboot_start, _bss_start, _bss_end);#ifdef CONFIG_MEMORY_UPPER_CODE /* by scsuh */debug("\t\bMalloc and Stack is above the U-Boot Code.\n");#elsedebug("\t\bMalloc and Stack is below the U-Boot Code.\n");#endif#ifdef CONFIG_MODEM_SUPPORTdebug ("Modem Support enabled\n");#endif#ifdef CONFIG_USE_IRQdebug ("IRQ Stack: %08lx\n", IRQ_STACK_START);debug ("FIQ Stack: %08lx\n", FIQ_STACK_START);#endifopen_backlight();//lqm.//open_gprs();return (0);}

?? ?????????????????串口輸出顯示uboot的logo,U_BOOT_VERSION在makefile中定義,編譯時生成到include/version_autogenerated.h的宏中

?? ?print_cpuinfo

?? ?

int print_cpuinfo(void){uint set_speed;uint tmp;uchar result_set;#if defined(CONFIG_CLK_533_133_100_100)set_speed = 53300;#elif defined(CONFIG_CLK_667_166_166_133)set_speed = 66700;#elif defined(CONFIG_CLK_800_200_166_133)set_speed = 80000;#elif defined(CONFIG_CLK_1000_200_166_133)set_speed = 100000;#elif defined(CONFIG_CLK_1200_200_166_133)set_speed = 120000;#elseset_speed = 100000;printf("Any CONFIG_CLK_XXX is not enabled\n");#endiftmp = (set_speed / (get_ARMCLK()/1000000));if((tmp < 105) && (tmp > 95)){result_set = 1;} else {result_set = 0;}#ifdef CONFIG_MCP_SINGLEprintf("\nCPU: ?S5PV210@%ldMHz(%s)\n", get_ARMCLK()/1000000, ((result_set == 1) ? "OK" : "FAIL"));#elseprintf("\nCPU: ?S5PC110@%ldMHz(%s)\n", get_ARMCLK()/1000000, ((result_set == 1) ? "OK" : "FAIL"));#endifprintf(" ? ? ? ?APLL = %ldMHz, HclkMsys = %ldMHz, PclkMsys = %ldMHz\n",get_FCLK()/1000000, get_HCLK()/1000000, get_PCLK()/1000000);#if 1printf("?? ?MPLL = %ldMHz, EPLL = %ldMHz\n",get_MPLL_CLK()/1000000, get_PLLCLK(EPLL)/1000000);printf("?? ??? ? ? ? ? HclkDsys = %ldMHz, PclkDsys = %ldMHz\n",get_HCLKD()/1000000, get_PCLKD()/1000000);printf("?? ??? ? ? ? ? HclkPsys = %ldMHz, PclkPsys = %ldMHz\n",get_HCLKP()/1000000, get_PCLKP()/1000000);printf("?? ??? ? ? ? ? SCLKA2M ?= %ldMHz\n", get_SCLKA2M()/1000000);#endifputs("Serial = CLKUART ");return 0;
}

CPU: ?S5PV210@1000MHz(OK)
APLL = 1000MHz, HclkMsys = 200MHz, PclkMsys = 100MHz
MPLL = 667MHz, EPLL = 96MHz
HclkDsys = 166MHz, PclkDsys = 83MHz
HclkPsys = 133MHz, PclkPsys = 66MHz
SCLKA2M ?= 200MHz
Serial = CLKUART?

????????????????print_cpuinfo打印uboot啟動時的cpu參數(shù)信息

?? ?????????checkboard

 ?int checkboard(void){#ifdef CONFIG_MCP_SINGLE#if defined(CONFIG_VOGUES)printf("\nBoard: ? VOGUESV210\n");#elseprintf("\nBoard: ? X210\n");#endif //CONFIG_VOGUES#elseprintf("\nBoard: ? X210\n");#endifreturn (0);}

????????????????打印開發(fā)板名字

?? ?init_func_i2c

?

? ?static int init_func_i2c (void){puts ("I2C: ? ");i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);puts ("ready\n");return (0);}

?? ?????????X210的uboot未使用I2C,此函數(shù)無用

?? ?dram_init

?? ?int dram_init(void){DECLARE_GLOBAL_DATA_PTR;gd->bd->bi_dram[0].start = PHYS_SDRAM_1;gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE;#if defined(PHYS_SDRAM_2)gd->bd->bi_dram[1].start = PHYS_SDRAM_2;gd->bd->bi_dram[1].size = PHYS_SDRAM_2_SIZE;#endif#if defined(PHYS_SDRAM_3)gd->bd->bi_dram[2].start = PHYS_SDRAM_3;gd->bd->bi_dram[2].size = PHYS_SDRAM_3_SIZE;#endifreturn 0;}

?? ?????????????????dram_init在一階段初始化low_level_init中初始化,此處為給全局變量定義賦值,記錄DDR配置(gd->bd->bi_dram)

?? ?display_dram_config

?? ?static int display_dram_config (void){int i;#ifdef DEBUGputs ("RAM Configuration:\n");for(i=0; i<CONFIG_NR_DRAM_BANKS; i++) {printf ("Bank #%d: %08lx ", i, gd->bd->bi_dram[i].start);print_size (gd->bd->bi_dram[i].size, "\n");}#elseulong size = 0;for (i=0; i<CONFIG_NR_DRAM_BANKS; i++) {size += gd->bd->bi_dram[i].size;}puts("DRAM: ? ?");print_size(size, "\n");#endifreturn (0);}

?? ?????????????????打印顯示dram配置信息,uboot啟動信息(DRAM: ? ?512 MB)在該處打印
?? ?????????????????uboot命令bdinfo,打印的位gd->bd中記錄硬件全局變量(DDR信息)

?? ?DRAM bank ? = 0x00000000-> start ? ?= 0x30000000-> size ? ? = 0x10000000DRAM bank ? = 0x00000001-> start ? ?= 0x40000000-> size ? ? = 0x10000000

堆管理器初始化

static void mem_malloc_init (ulong dest_addr)
{mem_malloc_start = dest_addr;mem_malloc_end = dest_addr + CFG_MALLOC_LEN;mem_malloc_brk = mem_malloc_start;memset ((void *) mem_malloc_start, 0,mem_malloc_end - mem_malloc_start);
}

????????初始化uboot堆管理器,DDR內(nèi)存中堆預(yù)留896KB

mmc初始化

#if defined(CONFIG_X210)#if defined(CONFIG_GENERIC_MMC)puts ("SD/MMC: ?");mmc_exist = mmc_initialize(gd->bd);if (mmc_exist != 0){puts ("0 MB\n");#ifdef CONFIG_CHECK_X210CV3check_flash_flag=0;//check inand error!#endif}#ifdef CONFIG_CHECK_X210CV3else{check_flash_flag=1;//check inand ok!?}#endif#endif#if defined(CONFIG_MTD_ONENAND)puts("OneNAND: ");onenand_init();/*setenv("bootcmd", "onenand read c0008000 80000 380000;bootm c0008000");*/#else//puts("OneNAND: (FSR layer enabled)\n");#endif#if defined(CONFIG_CMD_NAND)puts("NAND: ? ?");nand_init();#endif#endif /* CONFIG_X210 */

?? ?????????mmc_initialize是MMC基礎(chǔ)初始化(SoC內(nèi)部的SD/MMC控制器),函數(shù)在uboot/drivers/mmc/mmc.c
?? ?????????uboot對硬件操作(網(wǎng)卡、SD卡···)是用linux內(nèi)核驅(qū)動實現(xiàn)的(drivers目錄)
?? ?????????mmc_initialize初始化函數(shù)實際調(diào)用board_mmc_init和cpu_mmc_init初始化
?? ?????????cpu_mmc_init在uboot/cpu/s5pc11x/cpu.c,實際調(diào)用drivers/mmc/s3c_mmcxxx.c驅(qū)動代碼初始化MMC

環(huán)境變量重定位

?? ???

 ?/* initialize environment */env_relocate ();

?? ?????????SD卡有獨立扇區(qū)作為環(huán)境變量存儲區(qū)域,uboot代碼中包含默認環(huán)境變量,運行時會被讀取到DDR環(huán)境變量中,在寫入SD卡中

IP,MAC地址
??

 ?/* IP Address */gd->bd->bi_ip_addr = getenv_IPaddr ("ipaddr");/* MAC Address */{int i;ulong reg;char *s, *e;char tmp[64];i = getenv_r ("ethaddr", tmp, sizeof (tmp));s = (i > 0) ? tmp : NULL;for (reg = 0; reg < 6; ++reg) {gd->bd->bi_enetaddr[reg] = s ? simple_strtoul (s, &e, 16) : 0;if (s)s = (*e) ? e + 1 : e;}#ifdef CONFIG_HAS_ETH1i = getenv_r ("eth1addr", tmp, sizeof (tmp));s = (i > 0) ? tmp : NULL;for (reg = 0; reg < 6; ++reg) {gd->bd->bi_enet1addr[reg] = s ? simple_strtoul (s, &e, 16) : 0;if (s)s = (*e) ? e + 1 : e;}#endif}

?? ?????????初始化全局變量中的IP和MAC(gd->bd)

devices_init

int devices_init (void)
{#ifndef CONFIG_ARM ? ? /* already relocated for current ARM implementation */ulong relocation_offset = gd->reloc_off;int i;/* relocate device name pointers */for (i = 0; i < (sizeof (stdio_names) / sizeof (char *)); ++i) {stdio_names[i] = (char *) (((ulong) stdio_names[i]) +relocation_offset);}#endif/* Initialize the list */devlist = ListCreate (sizeof (device_t));if (devlist == NULL) {eputs ("Cannot initialize the list of devices!\n");return -1;}#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);#endif#ifdef CONFIG_LCDdrv_lcd_init ();#endif#if defined(CONFIG_VIDEO) || defined(CONFIG_CFB_CONSOLE)drv_video_init ();#endif#ifdef CONFIG_KEYBOARDdrv_keyboard_init ();#endif#ifdef CONFIG_LOGBUFFERdrv_logbuff_init ();#endifdrv_system_init ();#ifdef CONFIG_SERIAL_MULTIserial_devices_init ();#endif#ifdef CONFIG_USB_TTYdrv_usbtty_init ();#endif#ifdef CONFIG_NETCONSOLEdrv_nc_init ();#endifreturn (0);
}

????????函數(shù)執(zhí)行所有從linux內(nèi)核中繼承來的那些硬件驅(qū)動的初始化函數(shù)

跳轉(zhuǎn)表

void jumptable_init (void)
{int i;gd->jt = (void **) malloc (XF_MAX * sizeof (void *));for (i = 0; i < XF_MAX; i++)gd->jt[i] = (void *) dummy;gd->jt[XF_get_version] = (void *) get_version;gd->jt[XF_malloc] = (void *) malloc;gd->jt[XF_free] = (void *) free;gd->jt[XF_getenv] = (void *) getenv;gd->jt[XF_setenv] = (void *) setenv;gd->jt[XF_get_timer] = (void *) get_timer;gd->jt[XF_simple_strtoul] = (void *) simple_strtoul;gd->jt[XF_udelay] = (void *) udelay;gd->jt[XF_simple_strtol] = (void *) simple_strtol;gd->jt[XF_strcmp] = (void *) strcmp;#if defined(CONFIG_I386) || defined(CONFIG_PPC)gd->jt[XF_install_hdlr] = (void *) irq_install_handler;gd->jt[XF_free_hdlr] = (void *) irq_free_handler;#endif?? ?/* I386 || PPC */#if defined(CONFIG_CMD_I2C)gd->jt[XF_i2c_write] = (void *) i2c_write;gd->jt[XF_i2c_read] = (void *) i2c_read;#endif
}

?? ?????????未使用

控制臺二階段初始化

/* Called after the relocation - use desired console functions */
int console_init_r (void)
{device_t *inputdev = NULL, *outputdev = NULL;int i, items = ListNumItems (devlist);#ifdef CONFIG_SPLASH_SCREEN/* suppress all output if splash screen is enabled and we havea bmp to display ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?*/if (getenv("splashimage") != NULL)gd->flags |= GD_FLG_SILENT;#endif/* Scan devices looking for input and output devices */for (i = 1;(i <= items) && ((inputdev == NULL) || (outputdev == NULL));i++) {device_t *dev = ListGetPtrToItem (devlist, i);if ((dev->flags & DEV_FLAGS_INPUT) && (inputdev == NULL)) {inputdev = dev;}if ((dev->flags & DEV_FLAGS_OUTPUT) && (outputdev == NULL)) {outputdev = dev;}}/* Initializes output console first */if (outputdev != NULL) {console_setfile (stdout, outputdev);console_setfile (stderr, outputdev);}/* Initializes input console */if (inputdev != NULL) {console_setfile (stdin, inputdev);}gd->flags |= GD_FLG_DEVINIT;?? ?/* device initialization completed */#ifndef CFG_CONSOLE_INFO_QUIET/* Print information */puts ("In: ? ? ?");if (stdio_devices[stdin] == NULL) {puts ("No input devices available!\n");} else {printf ("%s\n", stdio_devices[stdin]->name);}puts ("Out: ? ? ");if (stdio_devices[stdout] == NULL) {puts ("No output devices available!\n");} else {printf ("%s\n", stdio_devices[stdout]->name);}puts ("Err: ? ? ");if (stdio_devices[stderr] == NULL) {puts ("No error devices available!\n");} else {printf ("%s\n", stdio_devices[stderr]->name);}#endif /* CFG_CONSOLE_INFO_QUIET */#ifndef?? ?CONFIG_X210/* Setting environment variables */for (i = 0; i < 3; i++) {setenv (stdio_names[i], stdio_devices[i]->name);}#endif#if 0/* If nothing usable installed, use only the initial console */if ((stdio_devices[stdin] == NULL) && (stdio_devices[stdout] == NULL))return (0);#endifreturn (0);
}

????????console_init_r初始化數(shù)據(jù)結(jié)構(gòu)配置值

使能中斷

void enable_interrupts (void)
{return;
}

初始化網(wǎng)卡地址

#ifdef CONFIG_DRIVER_CS8900cs8900_get_enetaddr (gd->bd->bi_enetaddr);
#endif初始化網(wǎng)卡地址(gd->bd)loadaddr和bootfile/* Initialize from environment */if ((s = getenv ("loadaddr")) != NULL) {load_addr = simple_strtoul (s, NULL, 16);}
#if defined(CONFIG_CMD_NET)if ((s = getenv ("bootfile")) != NULL) {copy_filename (BootFile, s, sizeof (BootFile));}

????????????????初始化環(huán)境變量,啟動linux內(nèi)核使用該值

空函數(shù)

#ifdef BOARD_LATE_INITboard_late_init ();
#endif
#if defined(CONFIG_CMD_NET)
#if defined(CONFIG_NET_MULTI)puts ("Net: ? ");
#endifeth_initialize(gd->bd);
#if defined(CONFIG_RESET_PHY_R)debug ("Reset Ethernet PHY\n");reset_phy();
#endif
#endif#if defined(CONFIG_CMD_IDE)puts("IDE: ? ");ide_init();
#endif

????????board_late_init,eth_initialize空函數(shù)

LCD初始化和logo顯示

#ifdef CONFIG_MPADextern int x210_preboot_init(void);x210_preboot_init();
#endifextern void mpadfb_init(void);
int x210_preboot_init(void)
{mpadfb_init();return 1;
}

void mpadfb_init()
{//?? ?unsigned short int *pFB;//榪欓噷涓€瀹氳鐢╯hort綾誨瀷!//?? ?int i;fb_init();//lqm masked for testlcd_port_init();lcd_reg_init();#ifdef CONFIG_CHECK_X210CV3init_logo();#endifdisplay_logo(&s5pv210_fb);#if(DISP_MODE == TRULY043)backlight_brigness_init(0);#else//AT070TN92backlight_brigness_init(1);#endif//?? ?pFB = (unsigned short int *)CFG_LCD_FBUFFER;/*for(i=0; i<800*480; i++)*pFB++ = 0xf800;*//*?? ? for(i=0; i<800*100; i++)*pFB++ = 0xf800;for(i=800*100; i<800*200; i++)*pFB++ = 0x07e0;for(i=800*200; i<800*480; i++)*pFB++ = 0x001f;*/#if(DISP_MODE == TRULY043)writel((readl(GPF3DAT) & ~(0x1<<5)) | (0x1<<5), GPF3DAT);#endif
}

快速燒錄(鏡像升級)

/* check menukey to update from sd */extern void update_all(void);if(check_menu_update_from_sd()==0)//update mode{puts ("[LEFT DOWN] update mode\n");run_command("fdisk -c 0",0);update_all();}elseputs ("[LEFT UP] boot mode\n");

????????鏡像燒錄到SD卡,開機按鍵LEFT鍵燒錄到iNand中

死循環(huán)

?? ?for (;;) {main_loop ();}/* NOTREACHED - no way out of command loop except booting */

????????開機延時，命令解析執(zhí)行

?

demo:

? ? ? ? 燒錄修改并編譯的uboot

make distclean && make x210_sd_config && makecd sd_fusing/make clean./sd_fusing.sh /dev/sdb

? ? ? ? 結(jié)果示例: