工作中需要将imx6的android系统从SD卡启动，所以就分析了MfgTool中的脚本，分析android的分区情况，并尝试自己操作，竟然成功了，记录于此。

参考文档

　　http://www.kancloud.cn/digest/imx6-android/148864

　　http://m.codes51.com/article/detail_239610_4.html

　　

sd卡重新分区

　　分区使用MfgTool中的mksdcard-android.sh脚本。下面对其进行分析。

　　需要将SD卡umount才能够从新进行分区。

#!/bin/bash# 运行 sh mksdcard-android.sh /dev/mmcblk0# partition size in MBBOOTLOAD_RESERVE=8  # bootloaderBOOT_ROM_SIZE=8     SYSTEM_ROM_SIZE=512 # system.imgCACHE_SIZE=512      # cacheRECOVERY_ROM_SIZE=8 # recoveryVENDER_SIZE=8       # vendorMISC_SIZE=8#显示帮助信息help() {bn=`basename $0`cat << EOFusage $bn  device_nodeoptions:  -h                displays this help message  -s                only get partition size  -np               not partition.  -f                flash android image.EOF}# check the if root?userid=`id -u`if [ $userid -ne "0" ]; then    echo "you're not root?"    exitfi# parse command linemoreoptions=1node="na"cal_only=0flash_images=0not_partition=0not_format_fs=0while [ "$moreoptions" = 1 -a $# -gt 0 ]; do    case $1 in        -h) help; exit ;;        -s) cal_only=1 ;;        -f) flash_images=1 ;;        -np) not_partition=1 ;;        -nf) not_format_fs=1 ;;        *)  moreoptions=0; node=$1 ;;    esac    [ "$moreoptions" = 0 ] && [ $# -gt 1 ] && help && exit    [ "$moreoptions" = 1 ] && shiftdoneif [ ! -e ${node} ]; then    help    exitfi# node /dev/mmcblk0# call sfdisk to create partition table# get total card sizeseprate=40# 查看分区大小,字节数total_size=`sfdisk -s ${node}`# 将字节转为Mtotal_size=`expr ${total_size} / 1024`boot_rom_sizeb=`expr ${BOOT_ROM_SIZE} + ${BOOTLOAD_RESERVE}`    # 8M + 8M = 16M#                    512M +  512M +  8M  + 8M + 40M = 1240Mextend_size=`expr ${SYSTEM_ROM_SIZE} + ${CACHE_SIZE} + ${VENDER_SIZE} + ${MISC_SIZE} + ${seprate}`#  data_size  =      total_size -  16M  -  8M - 1240M +  40M = total_size - 1224Mdata_size=`expr ${total_size} - ${boot_rom_sizeb} - ${RECOVERY_ROM_SIZE} - ${extend_size} + ${seprate}`# 这一部分只是显示计算的大小# create partitionsif [ "${cal_only}" -eq "1" ]; thencat << EOFBOOT   : ${boot_rom_sizeb}MBRECOVERY: ${RECOVERY_ROM_SIZE}MBSYSTEM : ${SYSTEM_ROM_SIZE}MBCACHE  : ${CACHE_SIZE}MBDATA   : ${data_size}MBMISC   : ${MISC_SIZE}MBEOFexitfi# 删除分区表# destroy the partition tabledd if=/dev/zero of=${node} bs=1024 count=1# 创建分区# sfdisk 命令 man 文档中有记录。# Id is given in hex, without the 0x prefix, or is [E|S|L|X], # where L (LINUX_NATIVE (83)) is the default, S is LINUX_SWAP (82), # E is EXTENDED_PARTITION (5), and X is LINUX_EXTENDED (85).# 指定分区大小，以及分区的类型，83，LINUX_NATIVE，5：扩展分区# 查案每种文件系统类型，可以通过命令 sfdisk -T 查看 sfdisk --force -uM ${node} << EOF,${boot_rom_sizeb},83       # 16M,${RECOVERY_ROM_SIZE},83    # 8M,${extend_size},5           # 1240M,${data_size},83            # total_size - 1224M,${SYSTEM_ROM_SIZE},83      # 512M,${CACHE_SIZE},83           # 512M,${VENDER_SIZE},83          # 8M,${MISC_SIZE},83            # 8MEOF# adjust the partition reserve for bootloader.# if you don't put the uboot on same device, you can remove the BOOTLOADER_ERSERVE# to have 8M space.# the minimal sylinder for some card is 4M, maybe some was 8M# just 8M for some big eMMC 's sylinder# 将/dev/mmcblk0分区之后的第一个分区进行调整sfdisk --force -uM ${node} -N1 << EOF${BOOTLOAD_RESERVE},${BOOT_ROM_SIZE},83EOF# For MFGTool Notes:# MFGTool use mksdcard-android.tar store this script# if you want change it.# do following:#   tar xf mksdcard-android.sh.tar#   vi mksdcard-android.sh #   [ edit want you want to change ]#   rm mksdcard-android.sh.tar; tar cf mksdcard-android.sh.tar mksdcard-android.sh

镜像拷贝到SD卡

　　这些内容也是从Mfgtool的ucl2.mxl文件中提取出来的。

　　制作成脚本repartition.sh，如下所示：

#!/bin/sh# Tony Liu  2016-8-3IMAGE_DIR="./image/"            #镜像文件存放的目录UBOOT=$IMAGE_DIR/u-boot.binBOOT_IMG=$IMAGE_DIR/boot.imgSYSTEM_IMG=$IMAGE_DIR/system.imgRECOVERY_IMG=$IMAGE_DIR/recovery.imgDEVICE=/dev/sdb                 #SD卡在linux中的设备节点，视实际情况而定MKSDCARD_SCRIPT=./mksdcard-android.sh   # android分区的脚本# 将SD卡分区   sh $MKSDCARD_SCRIPT $DEVICE# 对设备写0，每次块大小是512字节，从2 block的位置开始写，写2000次# 这里我猜想前面的1024字节应该是留给分区表的。dd if=/dev/zero of=$DEVICE bs=512 seek=2 count=2000         #Clean U-Bootenvironment# 写入u-boot.img。从u-boot.img开始2 block(skip=2)的位置开始读取数据# 写入的地址是设备偏移2block(seek=2)的位置(1M),块大小512字节。dd if=$UBOOT of=$DEVICE bs=512 seek=2 skip=2    #write U-Boot to sdcard# 写入boot.imgdd if=$BOOT_IMG of=${DEVICE}1            #write boot.img# 将SD卡的第4个分区格式化位ext4文件系统，并指定卷标名称为datamkfs.ext4 -L data ${DEVICE}4             #Formatting sd partitionmkfs.ext4 -L system ${DEVICE}5           #Formatting system partitionmkfs.ext4 -L cache -O^extent ${DEVICE}6  #Formatting cache partitionmkfs.ext4 -L vender ${DEVICE}7           #Formatting data partitionmkfs.ext4 ${DEVICE}8                     #Formatting misc partition# 写入system.imgdd if=$SYSTEM_IMG of=${DEVICE}5 bs=512   #Sending and writting system.img# 写入recovery.imgdd if=$RECOVERY_IMG of=${DEVICE}2 bs=512 #Sending and writting recovery.img

更改kernel启动位置

　　imx6从SD卡uboot启动之后，需要在SD卡中的uboot指定内核运行的SD卡序号，否者会运行开发板的emmc中。

　　可以在uboot中通过"mmc list"，查看有几块mmc。使用"booti mmc1",更改mmc序号，看是否能从SD卡启动，来判断SD卡的编号。

　　我的板子上SD卡的序号是mmc1。将uboot配置文件中mmc2更改为mmc1。这样一来，就选择从SD卡的内核启动。

　　vi mx6dl_sabresd_android.h

#define CONFIG_ANDROID_RECOVERY_BOOTCMD_MMC  \"booti mmc1 recovery"// Tony 2016-8-3//"booti mmc2 recovery"#define CONFIG_ANDROID_RECOVERY_CMD_FILE "/recovery/command"#define CONFIG_INITRD_TAG#undef CONFIG_LOADADDR#undef CONFIG_RD_LOADADDR#undef CONFIG_EXTRA_ENV_SETTINGS#define CONFIG_LOADADDR     0x10800000  /* loadaddr env var */#define CONFIG_RD_LOADADDR      0x11000000#define CONFIG_INITRD_TAG#define CONFIG_EXTRA_ENV_SETTINGS                   \        "netdev=eth0\0"                     \        "ethprime=FEC0\0"                   \        "fastboot_dev=mmc1\0"                   \        "bootcmd=booti mmc1\0"                  \        "splashimage=0x30000000\0"              \        "splashpos=m,m\0"                   \        "android_test=keyvalue\0"                   \        "bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:off video=mxcfb2:off fbmem=40M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \        "lvds_num=1\0"         #endif

更改ramdisk挂载位置

　　内核更改之后，需要将文件系统挂载到SD卡的分区上。

　　根据自己SD卡编号进行更改/dev/block/mmcblk后面的序号，我的是1。

　　vi fstab.freescale

# Android fstab file.# 
                 
       
        
                                                                                
        
         # The filesystem that contains the filesystem checker binary (typically /system) cannot# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK#Tony add for SD card boot/dev/block/mmcblk1p5    /system  ext4    ro                                                                               wait/dev/block/mmcblk1p4    /data    ext4    nosuid,nodev,nodiratime,noatime,nomblk_io_submit,noauto_da_alloc,errors=panic    wait,encryptable=footer/dev/block/mmcblk1p6    /cache   ext4    nosuid,nodev,nomblk_io_submit                                        wait/dev/block/mmcblk1p7    /device  ext4    ro,nosuid,nodev                                                  wait
        
       
      
     
    

　　运行脚本输出内容：

Tony@Tony:~/imx6_sdcard_boot$ sudo ./repartition.sh ###  首先进行SD卡分区1+0 records in1+0 records out1024 bytes (1.0 kB) copied, 0.00902186 s, 114 kB/sChecking that no-one is using this disk right now ...OKDisk /dev/sdb: 1022 cylinders, 245 heads, 62 sectors/tracksfdisk: ERROR: sector 0 does not have an msdos signature /dev/sdb: unrecognized partition table typeOld situation:No partitions foundWarning: given size (6520) exceeds max allowable size (6460)New situation:Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0   Device Boot Start   End    MiB    #blocks   Id  System/dev/sdb1         0+    22-    23-     22784+  83  Linux/dev/sdb2        22+    37-    15-     15190   83  Linux/dev/sdb3        37+  1119-  1083-   1108870    5  Extended/dev/sdb4      1119+  7639-  6520-   6676005   83  Linux/dev/sdb5        37+   556-   520-    531649+  83  Linux/dev/sdb6       556+  1075-   520-    531649+  83  Linux/dev/sdb7      1075+  1090-    15-     15189+  83  Linux/dev/sdb8      1090+  1105-    15-     15189+  83  LinuxWarning: partition 4 extends past end of diskSuccessfully wrote the new partition tableRe-reading the partition table ...If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)to zero the first 512 bytes:  dd if=/dev/zero of=/dev/foo7 bs=512 count=1(See fdisk(8).)Checking that no-one is using this disk right now ...OKDisk /dev/sdb: 1022 cylinders, 245 heads, 62 sectors/trackOld situation:Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0   Device Boot Start   End    MiB    #blocks   Id  System/dev/sdb1         0+    22-    23-     22784+  83  Linux/dev/sdb2        22+    37-    15-     15190   83  Linux/dev/sdb3        37+  1119-  1083-   1108870    5  Extended/dev/sdb4      1119+  7639-  6520-   6676005   83  Linux/dev/sdb5        37+   556-   520-    531649+  83  Linux/dev/sdb6       556+  1075-   520-    531649+  83  Linux/dev/sdb7      1075+  1090-    15-     15189+  83  Linux/dev/sdb8      1090+  1105-    15-     15189+  83  LinuxNew situation:Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0   Device Boot Start   End    MiB    #blocks   Id  System/dev/sdb1         7+    22-    15-     15190   83  Linux/dev/sdb2        22+    37-    15-     15190   83  Linux/dev/sdb3        37+  1119-  1083-   1108870    5  Extended/dev/sdb4      1119+  7639-  6520-   6676005   83  Linux/dev/sdb5        37+   556-   520-    531649+  83  Linux/dev/sdb6       556+  1075-   520-    531649+  83  Linux/dev/sdb7      1075+  1090-    15-     15189+  83  Linux/dev/sdb8      1090+  1105-    15-     15189+  83  LinuxWarning: partition 4 extends past end of diskSuccessfully wrote the new partition tableRe-reading the partition table ...If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)to zero the first 512 bytes:  dd if=/dev/zero of=/dev/foo7 bs=512 count=1(See fdisk(8).)#-------------------------------------------------------------------------------# 上面的内容是SD卡从新分区，下面进行dd文件拷贝2000+0 records in2000+0 records out1024000 bytes (1.0 MB) copied, 2.21602 s, 462 kB/s   # dd命令还能够测读写速度533+1 records in533+1 records out273172 bytes (273 kB) copied, 1.33912 s, 204 kB/s9916+0 records in9916+0 records out5076992 bytes (5.1 MB) copied, 11.7538 s, 432 kB/smke2fs 1.42 (29-Nov-2011)Filesystem label=dataOS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks413712 inodes, 1654536 blocks82726 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=169449881651 block groups32768 blocks per group, 32768 fragments per group8112 inodes per groupSuperblock backups stored on blocks:     32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632Allocating group tables: done                            Writing inode tables: done                            Creating journal (32768 blocks): doneWriting superblocks and filesystem accounting information: done mke2fs 1.42 (29-Nov-2011)Filesystem label=systemOS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks33280 inodes, 132912 blocks6645 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=1384120325 block groups32768 blocks per group, 32768 fragments per group6656 inodes per groupSuperblock backups stored on blocks:     32768, 98304Allocating group tables: done                            Writing inode tables: done                            Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: donemke2fs 1.42 (29-Nov-2011)Filesystem label=cacheOS type: LinuxBlock size=4096 (log=2)Fragment size=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks33280 inodes, 132912 blocks6645 blocks (5.00%) reserved for the super userFirst data block=0Maximum filesystem blocks=1384120325 block groups32768 blocks per group, 32768 fragments per group6656 inodes per groupSuperblock backups stored on blocks:     32768, 98304Allocating group tables: done                            Writing inode tables: done                            Creating journal (4096 blocks): doneWriting superblocks and filesystem accounting information: donemke2fs 1.42 (29-Nov-2011)Filesystem label=venderOS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)Stride=0 blocks, Stripe width=0 blocks3808 inodes, 15188 blocks759 blocks (5.00%) reserved for the super userFirst data block=1Maximum filesystem blocks=157286402 block groups8192 blocks per group, 8192 fragments per group1904 inodes per groupSuperblock backups stored on blocks:     8193Allocating group tables: done                            Writing inode tables: done                            Creating journal (1024 blocks): doneWriting superblocks and filesystem accounting information: donemke2fs 1.42 (29-Nov-2011)Filesystem label=OS type: LinuxBlock size=1024 (log=0)Fragment size=1024 (log=0)Stride=0 blocks, Stripe width=0 blocks3808 inodes, 15188 blocks759 blocks (5.00%) reserved for the super userFirst data block=1Maximum filesystem blocks=157286402 block groups8192 blocks per group, 8192 fragments per group1904 inodes per groupSuperblock backups stored on blocks:     8193Allocating group tables: done                            Writing inode tables: done                            Creating journal (1024 blocks): doneWriting superblocks and filesystem accounting information: done573440+0 records in573440+0 records out293601280 bytes (294 MB) copied, 61.2452 s, 4.8 MB/s10580+0 records in10580+0 records out5416960 bytes (5.4 MB) copied, 14.8084 s, 366 kB/s

Author

Tony Liu

2016-8-3, Shenzhen