搞高圆圆的小说全集:AT91RM9200引导程序的建立(三)--------U-Boot1.1.4在AT91R...

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AT91RM9200引导程序的建立(三)--------U-Boot1.1.4在AT91RM9200上的移植

 

BootLoader概述       Boot Loader就是在操作系统内核运行之前运行的一段小程序。通过这段BootLoader,我们来初始化硬件设备,为硬件设备准备地址空间,中断号等,建立内存空间的映射,从而将系统的软硬件环境带到一个合适的状态。AT91RM9200处理器启动有两种情况,一种是从外部启动,如Flash,EEPROM,DATAFLASH等;一种是从内部的BOOTROM固化代码引导。我们的ARM板是直接通过JTAG接口从主机下载到目标板的flash中直接启动。       系统上电后,我们的CPU从0x00000000取它的第一条指令,而我们的flash就是被映射到这个地址上。CPU就首先执行我们烧在flash上的BootLoader 程序,通过它来引导Linux系统。U-Boot是一个通用的Bootloader,可以方便地移植到其他硬件平台。现在已经成为ARM平台事实上的标准。U-Boot的源码包可以从sourceforge网站下载。我们使用U-Boot1.1.4来作为我们移植的Bootloader。 U-Boot1.1.4移植u-boot修改。由于我们的板子和atmel的DK板不同,所以针对我们的硬件,要重新修改u-boot代码,特别是flash驱动部分。 1)修改board/at91rm9200dk/config.mkTEXT_BASE=0x21f00000 将U-Boot载入32MSDRAM的高端部分,即最高端1M的空间留给U-Boot代码。 2)修改include/configs/at91rm9200dk.h 修改Flash和SDRAM的大小:    #define PHYS_SDRAM_SIZE 0x2000000 /* 32 megs */    #define PHYS_FLASH_SIZE 0x200000 /* 2 megs main flash */同时定义如下环境变量:#define CONFIG_DEFAULT_ENVIRONMENT
#define CONFIG_BOARDNAME "AT91RM9200DK"#define CONFIG_ETHADDR "00:11:22:33:44:55"#define CONFIG_IPADDR "192.168.1.100"#define CONFIG_SERVERIP "192.168.1.1"//#define CONFIG_GATEWAYIP "192.168.18.1"#define CONFIG_BOOTCOMMAND "tftp 0x20008000 zImage; tftp 0x20410000 ramdisk;go 0x20008000"#define CONFIG_DEFAULT_KERNEL "2.6.17"从上面可以看出,我们板子的IP地址是192.168.1.100,而我们的宿主机IP地址为192.168.1.1 ,我们的网卡Mac为:00:11:22:33:44:55。3)修改flash驱动borad/at91rm9200dk/flash.c这个文件修改的部分比较的多。1.     首先是OrgDef的定义,加上目前的flash。    OrgDef OrgSSTvF6401B[]={                                     {2048,4*1024},   /*2048*64KBytes sectors*/};修改函数flash_identification(flash_info_t * info),显示正确的信息。
void flash_identification (flash_info_t * info){       volatile u16 manuf_code, device_code, add_device_code;        MEM_FLASH_ADDR1 = FLASH_CODE1;       MEM_FLASH_ADDR2 = FLASH_CODE2;       MEM_FLASH_ADDR1 = ID_IN_CODE;        manuf_code = *(volatile u16 *) CFG_FLASH_BASE;       device_code = *(volatile u16 *) (CFG_FLASH_BASE + 2);       add_device_code = *(volatile u16 *) (CFG_FLASH_BASE + (3 << 1));        MEM_FLASH_ADDR1 = FLASH_CODE1;       MEM_FLASH_ADDR2 = FLASH_CODE2;       MEM_FLASH_ADDR1 = ID_OUT_CODE;        /* Vendor type */       /*       if(info->flash_id = ATM_MANUFACT & FLASH_VENDMASK)       {                 printf ("Atmel: ");       }       */       if(info->flash_id=SST_MANUFACT & FLASH_VENDMASK)    //zzl061206       {                 printf("SST:");       }/*atmel identify*/       if ((device_code & FLASH_TYPEMASK) == (ATM_ID_BV1614 & FLASH_TYPEMASK)) {                  if ((add_device_code & FLASH_TYPEMASK) ==                            (ATM_ID_BV1614A & FLASH_TYPEMASK)) {                            info->flash_id |= ATM_ID_BV1614A & FLASH_TYPEMASK;                            printf ("AT49BV1614A (16Mbit)\n");                 } else {                                 /* AT49BV1614 Flash */                            info->flash_id |= ATM_ID_BV1614 & FLASH_TYPEMASK;                            printf ("AT49BV1614 (16Mbit)\n");                 }        } else if ((device_code & FLASH_TYPEMASK) == (ATM_ID_BV6416 & FLASH_TYPEMASK)) {                    info->flash_id |= ATM_ID_BV6416 & FLASH_TYPEMASK;                 printf ("AT49BV6416 (64Mbit)\n");       }       /*sst identify*/      else if((device_code & FLASH_TYPEMASK) == (SST_ID_xF6401B & FLASH_TYPEMASK)) //zzl061206      {               info->flash_id |= SST_ID_xF6401B & FLASH_TYPEMASK;               printf("vF6401B(64Mbit)\n");      }} 2. 修改初始化Flash函数ulong flash_init (void)ulong flash_init (void){       int i, j, k;       unsigned int flash_nb_blocks, sector;       unsigned int start_address;       OrgDef *pOrgDef;        ulong size = 0;        for (i = 0; i < CFG_MAX_FLASH_BANKS; i++) {                 ulong flashbase = 0;                  flash_identification (&flash_info[i]);                  if ((flash_info[i].flash_id & FLASH_TYPEMASK) ==                            (ATM_ID_BV1614 & FLASH_TYPEMASK)) {                             pOrgDef = OrgAT49BV16x4;                            flash_nb_blocks = sizeof (OrgAT49BV16x4) / sizeof (OrgDef);                 } else if ((flash_info[i].flash_id & FLASH_TYPEMASK) ==                            (ATM_ID_BV1614A & FLASH_TYPEMASK)){      /* AT49BV1614A Flash */                             pOrgDef = OrgAT49BV16x4A;                            flash_nb_blocks = sizeof (OrgAT49BV16x4A) / sizeof (OrgDef);                 } else if ((flash_info[i].flash_id & FLASH_TYPEMASK) ==                            (ATM_ID_BV6416 & FLASH_TYPEMASK)){       /* AT49BV6416 Flash */                             pOrgDef = OrgAT49BV6416;                            flash_nb_blocks = sizeof (OrgAT49BV6416) / sizeof (OrgDef);                 }                 /*zzl*/               else if((flash_info[i].flash_id & FLASH_TYPEMASK)==                        (SST_ID_xF6401B & FLASH_TYPEMASK))               {                        pOrgDef=OrgSSTvF6401B;                        flash_nb_blocks = sizeof (OrgSSTvF6401B) / sizeof (OrgDef);               }                 else {                            flash_nb_blocks = 0;                            pOrgDef = OrgAT49BV16x4;                 }                  flash_info[i].sector_count = flash_number_sector(pOrgDef, flash_nb_blocks);                 memset (flash_info[i].protect, 0, flash_info[i].sector_count);                  if (i == 0)                            flashbase = PHYS_FLASH_1;                 else                            panic ("configured too many flash banks!\n");                  sector = 0;                 start_address = flashbase;                 flash_info[i].size = 0;                  for (j = 0; j < flash_nb_blocks; j++) {                            for (k = 0; k < pOrgDef[j].sector_number; k++) {                                      flash_info[i].start[sector++] = start_address;                                      start_address += pOrgDef[j].sector_size;                                      flash_info[i].size += pOrgDef[j].sector_size;                            }                 }                  size += flash_info[i].size;                  if ((flash_info[i].flash_id & FLASH_TYPEMASK) ==                            (ATM_ID_BV6416 & FLASH_TYPEMASK)){       /* AT49BV6416 Flash */   /*zzl*/                             /* Unlock all sectors at reset */                            for (j=0; jflash_id == FLASH_UNKNOWN)                 return ERR_UNKNOWN_FLASH_TYPE;        if ((s_first < 0) || (s_first > s_last)) {                 return ERR_INVAL;       }        if ((info->flash_id & FLASH_VENDMASK) !=                 (ATM_MANUFACT & FLASH_VENDMASK)) {                 return ERR_UNKNOWN_FLASH_VENDOR;       }*/但是这里出现了一个问题,编译后IP地址为0.192.168.1,serverip也是0.192.168.1。修改net/net.c中获得IP地址的函数。IPaddr_t getenv_IPaddr (char *var){       /*zzl*/       char tmp_str[64];       strcpy(tmp_str,getenv(var));if(isxdigit(*tmp_str))     /*测试环境变量字符是否是16进制,如果是,从第一个字符开始取4个字节,如果不是,则从第二个字符开始取4个字节。*/                 return (string_to_ip(tmp_str));       else                 return(string_to_ip(tmp_str+1));       /*old code       return (string_to_ip(getenv(var)));       */}重新编译#make distclean#make at91rm9200dk_config#make all编译成功后得到u-boot.bin的二进制文件,即为需要的可执行映象文件,将其用仿真器通过JTAG烧进flash中。板子重新上电,U-Boot启动成功。(注:U-Boot1.1.4已经不需要将其压缩为u-boot.gz。直接烧入flash的0地址后,便能启动,进入u-boot下。)