msm7630_surf flash device partition

msm7630 mmc flash partition table

read the MBR
dd if=/dev/block/mmcblk0 of=/sdcard/aa.bak bs=512 count=1
pull the MBR file and will analyze it
adb pull /sdcard/aa.bak .

split the MBR file to two parts include bootstrap codes and partition table record
split -b 446b aa.bak

ls -al
-rw-r--r--  1 alex alex  512 2011-09-27 09:22 aa.bak
-rw-r--r--  1 alex alex  446 2011-09-27 09:23 xaa
-rw-r--r--  1 alex alex   66 2011-09-27 09:23 xab

ghex2 xab



check the line two , the first bytes 80 it means this partition is a bootable partition.
the fifth byte of line 4 "05" means this is an external partition.

open the partition.xml
the section as follows
 
     
   

and the external partition sections
 
     
       
     
           
     
     
     
     
       
     
     
       
     
     
     
     
     
     
       
     
     
       
     
     
       
     
     
       
     
     
       
     
     
     
   


dbl.mbn will be wrote to this bootable partition.   (dbl= "Device Boot Loader")



code snapshot in lk

#define BLOCK_SIZE                0x200#define TABLE_ENTRY_0             0x1BE#define TABLE_ENTRY_1             0x1CE#define TABLE_ENTRY_2             0x1DE#define TABLE_ENTRY_3             0x1EE#define TABLE_SIGNATURE           0x1FE#define TABLE_ENTRY_SIZE          0x010

#define OFFSET_STATUS             0x00#define OFFSET_TYPE               0x04#define OFFSET_FIRST_SEC          0x08#define OFFSET_SIZE               0x0C

static unsigned int mmc_boot_read_MBR(void)
{
    unsigned char buffer[MMC_BOOT_RD_BLOCK_LEN];
    unsigned int dtype;
    unsigned int dfirstsec;
    unsigned int EBR_first_sec;
    unsigned int EBR_current_sec;
    int ret = 0;
    int idx, i;

    /* Print out the MBR first */
    ret = mmc_boot_read_from_card( &mmc_host, &mmc_card, 0, \
                                   MMC_BOOT_RD_BLOCK_LEN,   \
                                   (unsigned int *)buffer);
    if (ret)
    {
        return ret;
    }

    /* Check to see if signature exists */
    if ((buffer[TABLE_SIGNATURE] != 0x55) || \
        (buffer[TABLE_SIGNATURE + 1] != 0xAA))
    {
        dprintf(CRITICAL,  "MBR signature does not match. \n" );
        return MMC_BOOT_E_FAILURE;
    }

    /* Print out the first 4 partition */
    idx = TABLE_ENTRY_0;
    for (i = 0; i < 4; i++)
    {
        mbr[mmc_partition_count].dstatus = \
                    buffer[idx + i * TABLE_ENTRY_SIZE + OFFSET_STATUS];
        mbr[mmc_partition_count].dtype   = \
                    buffer[idx + i * TABLE_ENTRY_SIZE + OFFSET_TYPE];
        mbr[mmc_partition_count].dfirstsec = \
                    GET_LWORD_FROM_BYTE(&buffer[idx + \
                                        i * TABLE_ENTRY_SIZE + \
                                        OFFSET_FIRST_SEC]);
        mbr[mmc_partition_count].dsize  = \
                    GET_LWORD_FROM_BYTE(&buffer[idx + \
                                        i * TABLE_ENTRY_SIZE + \
                                        OFFSET_SIZE]);
        dtype  = mbr[mmc_partition_count].dtype;
        dfirstsec = mbr[mmc_partition_count].dfirstsec;
        mbr_fill_name(&mbr[mmc_partition_count],  \
                      mbr[mmc_partition_count].dtype);
        mmc_partition_count++;
        if (mmc_partition_count == MAX_PARTITIONS)
            return ret;
    }

    /* See if the last partition is EBR, if not, parsing is done */
    if (dtype != 0x05)
    {
        return ret;
    }

}

this is only  overlook view ,i will write more details about msm7630_surf partition table.