mini2440---board.c注释

/*
 * (C) Copyright 2002-2006
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <
 * Marius Groeger
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */


/*
 * To match the U-Boot user interface on ARM platforms to the U-Boot
 * standard (as on PPC platforms), some messages with debug character
 * are removed from the default U-Boot build.
 *
 * Define DEBUG here if you want additional info as shown below
 * printed upon startup:
 *
 * U-Boot code: 00F00000 -> 00F3C774  BSS: -> 00FC3274
 * IRQ Stack: 00ebff7c
 * FIQ Stack: 00ebef7c
 */


#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include   //tekkamanninja
#include   //tekkamanninja


#ifdef CONFIG_BITBANGMII
#include
#endif


#ifdef CONFIG_DRIVER_SMC91111
#include "../drivers/net/smc91111.h"
#endif
#ifdef CONFIG_DRIVER_LAN91C96
#include "../drivers/net/lan91c96.h"
#endif


DECLARE_GLOBAL_DATA_PTR;


ulong monitor_flash_len;


#ifdef CONFIG_HAS_DATAFLASH
extern int  AT91F_DataflashInit(void);
extern void dataflash_print_info(void);
#endif


#ifdef CONFIG_USB_DEVICE
extern void usb_init_slave(void);
#endif


#ifndef CONFIG_IDENT_STRING
#define CONFIG_IDENT_STRING ""
#endif


const char version_string[] =
U_BOOT_VERSION" (" U_BOOT_DATE " - " U_BOOT_TIME ")"CONFIG_IDENT_STRING;


#ifdef CONFIG_DRIVER_RTL8019
extern void rtl8019_get_enetaddr (uchar * addr);
#endif


#if defined(CONFIG_HARD_I2C) || \
    defined(CONFIG_SOFT_I2C)
#include
#endif


#if 0
/************************************************************************
 * Coloured LED functionality
 ************************************************************************
 * May be supplied by boards if desired
 */
void inline __coloured_LED_init (void) {}
void coloured_LED_init (void) __attribute__((weak, alias("__coloured_LED_init")));
void inline __red_LED_on (void) {}
void red_LED_on (void) __attribute__((weak, alias("__red_LED_on")));
void inline __red_LED_off(void) {}
void red_LED_off(void) __attribute__((weak, alias("__red_LED_off")));
void inline __green_LED_on(void) {}
void green_LED_on(void) __attribute__((weak, alias("__green_LED_on")));
void inline __green_LED_off(void) {}
void green_LED_off(void) __attribute__((weak, alias("__green_LED_off")));
void inline __yellow_LED_on(void) {}
void yellow_LED_on(void) __attribute__((weak, alias("__yellow_LED_on")));
void inline __yellow_LED_off(void) {}
void yellow_LED_off(void) __attribute__((weak, alias("__yellow_LED_off")));
void inline __blue_LED_on(void) {}
void blue_LED_on(void) __attribute__((weak, alias("__blue_LED_on")));
void inline __blue_LED_off(void) {}
void blue_LED_off(void) __attribute__((weak, alias("__blue_LED_off")));
#endif


/************************************************************************
 * Init Utilities *
 ************************************************************************
 * Some of this code should be moved into the core functions,
 * or dropped completely,
 * but let's get it working (again) first...
 */


#if defined(CONFIG_ARM_DCC) && !defined(CONFIG_BAUDRATE)
#define CONFIG_BAUDRATE 115200
#endif
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);
}


static int display_banner (void)
{
#if defined(CONFIG_MINI2440_LED)
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
writel(0x101, &gpio->GPBDAT);  //tekkamanninja
#endif
printf ("\n\n%s\n\n", version_string);
printf (" modified by tekkamanninja ([e-mail])\n");
printf (" Love Linux forever!!\n\n");
debug ("U-Boot code: %08lX -> %08lX  BSS: -> %08lX\n",
      _armboot_start, _bss_start, _bss_end);
#ifdef CONFIG_MODEM_SUPPORT
debug ("Modem Support enabled\n");
#endif
#ifdef CONFIG_USE_IRQ
debug ("IRQ Stack: %08lx\n", IRQ_STACK_START);
debug ("FIQ Stack: %08lx\n", FIQ_STACK_START);
#endif


return (0);
}


/*
 * WARNING: this code looks "cleaner" than the PowerPC version, but
 * has the disadvantage that you either get nothing, or everything.
 * On PowerPC, you might see "DRAM: " before the system hangs - which
 * gives a simple yet clear indication which part of the
 * initialization if failing.
 */
static int display_dram_config (void)
{
int i;


#ifdef DEBUG
puts ("RAM Configuration:\n");


for(i=0; i printf ("Bank #%d: %08lx ", i, gd->bd->bi_dram[i].start);
print_size (gd->bd->bi_dram[i].size, "\n");
}
#else
ulong size = 0;


for (i=0; i size += gd->bd->bi_dram[i].size;
}
puts("DRAM:  ");
print_size(size, "\n");
#endif


return (0);
}


#ifndef CONFIG_SYS_NO_FLASH
static void display_flash_config (ulong size)
{
puts ("Flash: ");
print_size (size, "\n");
}
#endif /* CONFIG_SYS_NO_FLASH */


#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)
static int init_func_i2c (void)
{
puts ("I2C:   ");
i2c_init (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
puts ("ready\n");
return (0);
}
#endif


#if defined(CONFIG_CMD_PCI) || defined (CONFIG_PCI)
#include
static int arm_pci_init(void)
{
pci_init();
return 0;
}
#endif /* CONFIG_CMD_PCI || CONFIG_PCI */


/*
 * Breathe some life into the board...
 *
 * Initialize a serial port as console, and carry out some hardware
 * tests.
 *
 * The first part of initialization is running from Flash memory;
 * its main purpose is to initialize the RAM so that we
 * can relocate the monitor code to RAM.
 */


/*
 * All attempts to come up with a "common" initialization sequence
 * that works for all boards and architectures failed: some of the
 * requirements are just _too_ different. To get rid of the resulting
 * mess of board dependent #ifdef'ed code we now make the whole
 * initialization sequence configurable to the user.
 *
 * The requirements for any new initalization function is simple: it
 * receives a pointer to the "global data" structure as it's only
 * argument, and returns an integer return code, where 0 means
 * "continue" and != 0 means "fatal error, hang the system".
 */
 //指定初始函数表，调用一系列初试化函数///////////////////////
typedef int (init_fnc_t) (void);   //类似于函数指针的一个别名


//int (*p)(void);函数指针======>上面少了一个*，所以不是函数指针
//init_fnc_t代表一个类型。
//int a[10]; int 是成员的类型；
//init_fnc_t *a[10];数组成员是函数指针


int print_cpuinfo (void);


//init_sequence 数组，里面的成员是init_fnc_t   * 类型的函数指针
init_fnc_t *init_sequence[] = {       //函数指针的数组=====>成员为函数的初始化


//下面是成员函数。。。赖
#if defined(CONFIG_ARCH_CPU_INIT)
arch_cpu_init, /* basic arch cpu dependent setup *///==========>0元素
#endif
board_init, /* basic board dependent setup */
#if defined(CONFIG_USE_IRQ)
interrupt_init, /* set up exceptions */
#endif
timer_init, /* initialize timer */
#ifdef CONFIG_FSL_ESDHC
get_clocks,
#endif
env_init, /* initialize environment */
init_baudrate, /* initialze baudrate settings */
serial_init, /* serial communications setup */
console_init_f, /* stage 1 init of console */    //   控制台初试化第一阶段
display_banner, /* say that we are here 打印uboot信息 */      //    通知代码已经搬运到该处
#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,
#endif
dram_init, /* configure available RAM banks */
#if defined(CONFIG_CMD_PCI) || defined (CONFIG_PCI)
arm_pci_init,
#endif
display_dram_config, //显示RAM配置的大小 --lib_arm/board.c 
NULL,
};


/*************************************************************************
***************第二阶段的入口 初始化外围设备********************************************
************************************************************************/
void start_armboot (void)
{
init_fnc_t **init_fnc_ptr;   //函数指针的指针====init_fnc_t函数指针，定义加个*就是指针的指针
//指向上面那个数组
char *s;


//定义变量，给变量赋值
#if defined(CONFIG_VFD) || defined(CONFIG_LCD)
unsigned long addr;
#endif
#if defined(CONFIG_MINI2440_LED)
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
#endif
/* Pointer is writable since we allocated a register for it */
//获取全局gd指针
gd = (gd_t*)(_armboot_start - CONFIG_SYS_MALLOC_LEN - sizeof(gd_t));
/* compiler optimization barrier needed for GCC >= 3.4 */


//__*__是声明。在此内联汇编语句出现的位置内存内容可能改变了，  
__asm__ __volatile__("": : :"memory");       //向GCC声明：“我对内存作了改动”，GCC在编译的时候，会将此因素考虑进去。


memset ((void*)gd, 0, sizeof (gd_t));        //清空gd指向的结构//地址的清零，因为现在还没有做任何操作
gd->bd = (bd_t*)((char*)gd - sizeof(bd_t));//获取bd_info结构体指针
memset (gd->bd, 0, sizeof (bd_t));  //清空bd指向的结构 
                                         //准备好保存参数的全局变量区
gd->flags |= GD_FLG_RELOC;


monitor_flash_len = _bss_start - _armboot_start;  //uboot 长度


//init_fnc_ptr指针的指针取内容，还是内容
//*init_fnc_ptr是指针，条件不等于NULL
for (init_fnc_ptr = init_sequence; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr)() != 0) {          //执行初试化函数===函数名加()，执行函数，得出一个返回值成功0
hang (); //可用电灯来判断到底是执行到哪个函数
}
}


/* armboot_start is defined in the board-specific linker script */
mem_malloc_init (_armboot_start - CONFIG_SYS_MALLOC_LEN,
CONFIG_SYS_MALLOC_LEN);


#ifndef CONFIG_SYS_NO_FLASH//未定义
/* configure available FLASH banks */
display_flash_config (flash_init ());//nor === flash_init
//nand====nand_inits
#endif /* CONFIG_SYS_NO_FLASH */


//给浮点运算保留空间CONFIG_VFD ，CONFIG_VFD 没定义。不执行。
#ifdef CONFIG_VFD//未定义
# ifndef PAGE_SIZE
#  define PAGE_SIZE 4096
# endif
/*
* reserve memory for VFD display (always full pages)
*/
/* bss_end is defined in the board-specific linker script */
addr = (_bss_end + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
vfd_setmem (addr);
gd->fb_base = addr;
#endif /* CONFIG_VFD */


#ifdef CONFIG_LCD  //CONFIG_LCD 没定义。不执行。
/* board init may have inited fb_base */
if (!gd->fb_base) {
# ifndef PAGE_SIZE
#  define PAGE_SIZE 4096
# endif
/*
* reserve memory for LCD display (always full pages)
*/
/* bss_end is defined in the board-specific linker script */
addr = (_bss_end + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
lcd_setmem (addr);
gd->fb_base = addr;
}
#endif /* CONFIG_LCD */


#if defined(CONFIG_CMD_NAND)//有定义
puts ("NAND:  ");
nand_init(); /* go init the NAND */
#endif


#if defined(CONFIG_CMD_ONENAND)//未定义
onenand_init();
#endif


#ifdef CONFIG_HAS_DATAFLASH//CONFIG_HAS_DATAFLASH 没定义。不执行。
AT91F_DataflashInit();
dataflash_print_info();
#endif


/* initialize environment */
env_relocate ();                              //初始化环境变量


#ifdef CONFIG_VFD//未定义
/* must do this after the framebuffer is allocated */
drv_vfd_init();
#endif /* CONFIG_VFD */


#ifdef CONFIG_SERIAL_MULTI//未定义
serial_initialize();
#endif


/* IP Address */
gd->bd->bi_ip_addr = getenv_IPaddr ("ipaddr");       //P309i从环境变量中获取IP地址


stdio_init (); /* get the devices list going. */


jumptable_init ();


#if defined(CONFIG_API)
/* Initialize API */
api_init ();
#endif


console_init_r (); /* fully init console as a device */


#if defined(CONFIG_ARCH_MISC_INIT)
/* miscellaneous arch dependent initialisations */
arch_misc_init ();
#endif
#if defined(CONFIG_MISC_INIT_R)
/* miscellaneous platform dependent initialisations */
misc_init_r ();
#endif
/* enable exceptions */
enable_interrupts ();      //使能例外处理=========刚才关闭中断=使能中断


#ifdef CONFIG_USB_DEVICE
usb_init_slave();  //USB初始化
#endif
/* Perform network card initialisation if necessary */
#ifdef CONFIG_DRIVER_TI_EMAC//未定义
/* XXX: this needs to be moved to board init */
extern void davinci_eth_set_mac_addr (const u_int8_t *addr);
if (getenv ("ethaddr")) {
uchar enetaddr[6];
eth_getenv_enetaddr("ethaddr", enetaddr);
davinci_eth_set_mac_addr(enetaddr);
}
#endif


#if defined(CONFIG_DRIVER_SMC91111) || defined (CONFIG_DRIVER_LAN91C96)//未定义
/* XXX: this needs to be moved to board init */
if (getenv ("ethaddr")) {
uchar enetaddr[6];
eth_getenv_enetaddr("ethaddr", enetaddr);
smc_set_mac_addr(enetaddr);
}
#endif /* CONFIG_DRIVER_SMC91111 || CONFIG_DRIVER_LAN91C96 */


/* Initialize from environment */
if ((s = getenv ("loadaddr")) != NULL) {//loadaddr内核加载的地址
load_addr = simple_strtoul (s, NULL, 16);
}
#if defined(CONFIG_CMD_NET)//未定义
if ((s = getenv ("bootfile")) != NULL) {
copy_filename (BootFile, s, sizeof (BootFile));
}
#endif


#ifdef BOARD_LATE_INIT//未定义
board_late_init ();
#endif


#ifdef CONFIG_GENERIC_MMC//未定义
puts ("MMC:   ");
mmc_initialize (gd->bd);
#endif


#ifdef CONFIG_BITBANGMII//未定义
bb_miiphy_init();
#endif
#if defined(CONFIG_CMD_NET)//未定义
#if defined(CONFIG_NET_MULTI)//未定义
puts ("Net:   ");
#endif
eth_initialize(gd->bd);
#if defined(CONFIG_RESET_PHY_R)//未定义
debug ("Reset Ethernet PHY\n");
reset_phy();
#endif
#endif
#if defined(CONFIG_MINI2440_LED) //有定义
writel(0x0, &gpio->GPBDAT);  //tekkamanninja
#endif
 
#if defined(CONFIG_CFB_CONSOLE)        //有定义
printf ("%s\n", version_string);
printf ("modified by tekkamanninja\n([e-mail])\n");
printf ("Love Linux forever!!\n");
#endif
/* main_loop() can return to retry autoboot, if so just run it again. */
for (;;) {//死循环
main_loop ();      //准备引导内核 //common/main.c获取一些环境变量    等待终端输入
}


/* NOTREACHED - no way out of command loop except booting */
}


void hang (void)//只是停留在这边不动。
{
puts ("### ERROR ### Please RESET the board ###\n");
for (;;);
}