android系统移植emmc记录(5)-- fastboot命令分析

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int do_fastboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])

{//设置u-boot，kernel，ramdisk ，system，userdata，cache空间地址

       if (set_partition_table())



---------------------------------------->  // set_partition_table
   //主要设置bootloader ramdisk kernel 和fdisk所分的区的起始地址和大小，保存在ptable里面。

       /* Bootloader */

       strcpy(ptable[pcount].name, "bootloader");

       ptable[pcount].start = 0;

       ptable[pcount].length = 0;

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MOVI_CMD;

       pcount++;



       /* Kernel */

       strcpy(ptable[pcount].name, "kernel");

       ptable[pcount].start = 0;

       ptable[pcount].length = 0;

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MOVI_CMD;

       pcount++;



       /* Ramdisk  3M */

       strcpy(ptable[pcount].name, "ramdisk");

       ptable[pcount].start = 0;

       ptable[pcount].length = 0x300000; //3MB,初始值，如果文件大于3M，则会使用文件大小

       //写ramdisk的命令类型标志，这里用movi命令来写

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MOVI_CMD;

       pcount++;

       -----------------------

       /* System */

       get_mmc_part_info("0", 2, &start, &count, &pid);

       -------------------------

       if (pid != 0x83)

              goto part_type_error;

       strcpy(ptable[pcount].name, "system");

/*

                     decode_partitionInfo(&mbr[0x1CE], &partInfo);

                     *block_start    = partInfo.block_start;

                     *block_count  = partInfo.block_count;

                     *part_Id        = partInfo.partitionId;

*/    //system 开始的地址

       ptable[pcount].start = start * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       //大小，256M

       ptable[pcount].length = count * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       //写system数据类型的标志，这里用MMC命令来写

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MMC_CMD;

       pcount++;



       /* Data  350M*/

       get_mmc_part_info("0", 3, &start, &count, &pid);

       if (pid != 0x83)

              goto part_type_error;

       strcpy(ptable[pcount].name, "userdata");

       ptable[pcount].start = start * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].length = count * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MMC_CMD;

       pcount++;



       /* Cache  100 M */

       get_mmc_part_info("0", 4, &start, &count, &pid);

       if (pid != 0x83)

              goto part_type_error;

       strcpy(ptable[pcount].name, "cache");

       ptable[pcount].start = start * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].length = count * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MMC_CMD;

       pcount++;



       /* fat 剩余空间分区，剩余空间分区格式fat？标志为 0c*/

       get_mmc_part_info("0", 1, &start, &count, &pid);

       if (pid != 0xc)

              goto part_type_error;

       strcpy(ptable[pcount].name, "fat");

       ptable[pcount].start = start * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].length = count * CFG_FASTBOOT_SDMMC_BLOCKSIZE;

       ptable[pcount].flags = FASTBOOT_PTENTRY_FLAGS_USE_MMC_CMD;

       pcount++;



-------------->
<PRE class=cpp name="code">---------------------------->
//获取fdisk 对system userdata  cache分区的大小
int get_mmc_part_info(char *device_name, int part_num, int *block_start, int *block_count, unsigned char *part_Id)
{
    int     rv;
    PartitionInfo   partInfo;
    unsigned char   mbr[512];
    //从设备0中读取MBR主分区目录，里面定义了各个分区的信息，和起始，结束扇区
    rv = get_mmc_mbr(device_name, mbr);

    if(rv !=0)
        return -1;

    switch(part_num)
    {
        //剩余容量空间
        case 1:
            decode_partitionInfo(&mbr[0x1BE], &partInfo);
            *block_start    = partInfo.block_start;
            *block_count    = partInfo.block_count;
            *part_Id    = partInfo.partitionId;
            break;
        //system 分区表2。fdisk给system分了256M大小
        case 2:
            decode_partitionInfo(&mbr[0x1CE], &partInfo);
            *block_start    = partInfo.block_start;
            *block_count    = partInfo.block_count;
            *part_Id    = partInfo.partitionId; //83
            break;
        //userdata 分区
        case 3:
            decode_partitionInfo(&mbr[0x1DE], &partInfo);
            *block_start    = partInfo.block_start;
            *block_count    = partInfo.block_count;
            *part_Id    = partInfo.partitionId;
            break;
        //cache分区
        case 4:
            decode_partitionInfo(&mbr[0x1EE], &partInfo);
            *block_start    = partInfo.block_start;
            *block_count    = partInfo.block_count;
            *part_Id    = partInfo.partitionId;
            break;
        default:
            return -1;
    }

    return 0;
}

1. //擦除接口 fastboot erase    
2. if (memcmp(cmdbuf, "erase:", 6) == 0)  
3.         {  
4.             struct fastboot_ptentry *ptn;  
5.   
6.             ptn = fastboot_flash_find_ptn(cmdbuf + 6);  
7.             if (ptn == 0)  
8.   
9. ------------------------------------------------------------  
10. //获取fat system userdata cache 分区名字   
11. fastboot_ptentry *fastboot_flash_find_ptn(const char *name)  
12. {  
13.     unsigned int n;  
14.       
15.     for (n = 0; n < pcount; n++)  
16.     {  
17.         /* Make sure a substring is not accepted */  
18.         if (strlen(name) == strlen(ptable[n].name))  
19.         {  
20.             if (0 == strcmp(ptable[n].name, name))  
21.                 return ptable + n;  
22.         }  
23.     }  
24.     return 0;  
25. }  
26. -------------------------------------------------------  
27.   
28. //只有擦除userdata  cache fat 这几个功能，kernel u-boot  ramdisk 不能擦除   
29. //其实就是调用ext3format fatmot等格式命令 ，需要添加system 擦除命令   
30.             char run_cmd[80];  
31.             status = 1;  
32.   
33.             if (!strcmp(ptn->name, "sytem"))  
34.             {  
35.                 sprintf(run_cmd, "ext3format mmc 0:2");  
36.                 status = run_command(run_cmd, 0);  
37.             }  
38.             Else if (!strcmp(ptn->name, "userdata"))  
39.             {  
40.                 sprintf(run_cmd, "ext3format mmc 0:3");  
41.                 status = run_command(run_cmd, 0);  
42.             }  
43.             else if (!strcmp(ptn->name, "cache"))  
44.             {  
45.                 sprintf(run_cmd, "ext3format mmc 0:4");  
46.                 status = run_command(run_cmd, 0);  
47.             }  
48.             else if (!strcmp(ptn->name, "fat"))  
49.             {  
50.                 sprintf(run_cmd, "fatformat mmc 0:1");  
51.                 status = run_command(run_cmd, 0);  
52.             }  
53. =======================================================  
54. </PRE>  
55. <P><BR>  
56.  </P>  
57. <PRE class=cpp name="code">Flash what was downloaded */  
58.         if (memcmp(cmdbuf, "flash:", 6) == 0)  
59.         {  
60.             if (download_bytes == 0)  
61.             {  
62.                 sprintf(response, "FAILno image downloaded");  
63.                 ret = 0;  
64.                 goto send_tx_status;  
65.             }  
66.             //从此句开始判断 kernel。 ramdisk system,获取ptable   
67.             ptn = fastboot_flash_find_ptn(cmdbuf + 6);  
68.             ----------------------  
69.             if ((download_bytes > ptn->length) && (ptn->length != 0) &&      
70.                    !(ptn->flags & FASTBOOT_PTENTRY_FLAGS_WRITE_ENV))  
71.             { //注意。system写，会出现这个信息。注意检查   
72.              //分析，只有当system文件大小小于分区大小时，是不会进入的   
73.                 sprintf(response, "FAILimage too large for partition");  
74.                 /* TODO : Improve check for yaffs write */  
75.             }  
76.             else  
77.             {  
78.                     /* Normal case */  
79.                     if (write_to_ptn(ptn, (unsigned int)interface.transfer_buffer, download_bytes))  
80.                     {  
81.                         printf("flashing '%s' failed\n", ptn->name);  
82.                         sprintf(response, "FAILfailed to flash partition");  
83.                     }  
84.                     else  
85.                     {  
86.                         printf("partition '%s' flashed\n", ptn->name);  
87.                         sprintf(response, "OKAY");  
88.                     }  
89.             }  
90.             -------------------------------------------  

http://blog.csdn.net/yunfly163/article/details/7496869