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 MB
BOOTLOAD_RESERVE=8 # bootloader
BOOT_ROM_SIZE=8
SYSTEM_ROM_SIZE=512 # system.img
CACHE_SIZE=512 # cache
RECOVERY_ROM_SIZE=8 # recovery
VENDER_SIZE=8 # vendor
MISC_SIZE=8
#显示帮助信息
help() {
bn=`basename $0`
cat << EOF
usage $bn <option> device_node
options:
-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 [ $userid -ne "0" ]; then
echo "you're not root?"
exit
fi
# parse command line
moreoptions=1
node="na"
cal_only=0
flash_images=0
not_partition=0
not_format_fs=0
while [ "$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 ] && shift
done
if [ ! -e ${node} ]; then
help
exit
fi
# node /dev/mmcblk0
# call sfdisk to create partition table
# get total card size
seprate=40
# 查看分区大小,字节数
total_size=`sfdisk -s ${node}`
# 将字节转为M
total_size=`expr ${total_size} / 1024`
boot_rom_sizeb=`expr ${BOOT_ROM_SIZE} + ${BOOTLOAD_RESERVE}` # 8M + 8M = 16M
# 512M + 512M + 8M + 8M + 40M = 1240M
extend_size=`expr ${SYSTEM_ROM_SIZE} + ${CACHE_SIZE} + ${VENDER_SIZE} + ${MISC_SIZE} + ${seprate}`
# data_size = total_size - 16M - 8M - 1240M + 40M = total_size - 1224M
data_size=`expr ${total_size} - ${boot_rom_sizeb} - ${RECOVERY_ROM_SIZE} - ${extend_size} + ${seprate}`
# 这一部分只是显示计算的大小
# create partitions
if [ "${cal_only}" -eq "1" ]; then
cat << EOF
BOOT : ${boot_rom_sizeb}MB
RECOVERY: ${RECOVERY_ROM_SIZE}MB
SYSTEM : ${SYSTEM_ROM_SIZE}MB
CACHE : ${CACHE_SIZE}MB
DATA : ${data_size}MB
MISC : ${MISC_SIZE}MB
EOF
exit
fi
# 删除分区表
# destroy the partition table
dd if=/dev/zero of=${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 # 8M
EOF
# 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},83
EOF
# 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 2016-8-3
IMAGE_DIR="./image/" #镜像文件存放的目录
UBOOT=$IMAGE_DIR/u-boot.bin
BOOT_IMG=$IMAGE_DIR/boot.img
SYSTEM_IMG=$IMAGE_DIR/system.img
RECOVERY_IMG=$IMAGE_DIR/recovery.img
DEVICE=/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.img
dd 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data
mkfs.ext4 -L data ${DEVICE}4 #Formatting sd partition
mkfs.ext4 -L system ${DEVICE}5 #Formatting system partition
mkfs.ext4 -L cache -O^extent ${DEVICE}6 #Formatting cache partition
mkfs.ext4 -L vender ${DEVICE}7 #Formatting data partition
mkfs.ext4 ${DEVICE}8 #Formatting misc partition
# 写入system.img
dd if=$SYSTEM_IMG of=${DEVICE}5 bs=512 #Sending and writting system.img
# 写入recovery.img
dd if=$RECOVERY_IMG of=${DEVICE}2 bs=512 #Sending and writting recovery.img</CMD>
更改kernel启动位置
imx6从SD卡uboot启动之后，需要在SD卡中的uboot指定内核运行的SD卡序号，否者会运行开发板的emmc中。
可以在uboot中通过"mmc list"，查看有几块mmc。使用"booti mmc1",更改mmc序号，看是否能从SD卡启动，来判断SD卡的编号。
我的板子上SD卡的序号是mmc1。将uboot配置文件中mmc2更改为mmc1。这样一来，就选择从SD卡的内核启动。
vi mx6dl_sabresd_android.h
#define CONFIG_ANDROID_RECOVERY_BOOTCMD_MMC \
"booti mmc1 recovery"
// Tony 2016-8-3
//"booti mmc2 recovery"
#define CONFIG_ANDROID_RECOVERY_CMD_FILE "/recovery/command"
#define CONFIG_INITRD_TAG
#undef CONFIG_LOADADDR
#undef CONFIG_RD_LOADADDR
#undef CONFIG_EXTRA_ENV_SETTINGS
#define CONFIG_LOADADDR 0x10800000 /* loadaddr env var */
#define CONFIG_RD_LOADADDR 0x11000000
#define CONFIG_INITRD_TAG
#define CONFIG_EXTRA_ENV_SETTINGS \
"netdev=eth0\0" \
"ethprime=FEC0\0" \
"fastboot_dev=mmc1\0" \
"bootcmd=booti mmc1\0" \
"splashimage=0x30000000\0" \
"splashpos=m,m\0" \
"android_test=keyvalue\0" \
"bootargs=console=ttymxc0,115200 init=/init video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:off video=mxcfb2:off fbmem=40M fb0base=0x27b00000 vmalloc=400M androidboot.console=ttymxc0 androidboot.hardware=freescale\0" \
"lvds_num=1\0"
#endif
更改ramdisk挂载位置
内核更改之后，需要将文件系统挂载到SD卡的分区上。
根据自己SD卡编号进行更改/dev/block/mmcblk后面的序号，我的是1。
vi fstab.freescale
# Android fstab file.
# <src> <mnt_point> <type> <mnt_flags> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK
#Tony add for SD card boot
/dev/block/mmcblk1p5 /system ext4 ro wait
/dev/block/mmcblk1p4 /data ext4 nosuid,nodev,nodiratime,noatime,nomblk_io_submit,noauto_da_alloc,errors=panic wait,encryptable=footer
/dev/block/mmcblk1p6 /cache ext4 nosuid,nodev,nomblk_io_submit wait
/dev/block/mmcblk1p7 /device ext4 ro,nosuid,nodev wait
运行脚本输出内容：
Tony@Tony:~/imx6_sdcard_boot$ sudo ./repartition.sh
### 首先进行SD卡分区
1+0 records in
1+0 records out
1024 bytes (1.0 kB) copied, 0.00902186 s, 114 kB/s
Checking that no-one is using this disk right now ...
OK
Disk /dev/sdb: 1022 cylinders, 245 heads, 62 sectors/track
sfdisk: ERROR: sector 0 does not have an msdos signature
/dev/sdb: unrecognized partition table type
Old situation:
No partitions found
Warning: 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 Linux
Warning: partition 4 extends past end of disk
Successfully wrote the new partition table
Re-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 ...
OK
Disk /dev/sdb: 1022 cylinders, 245 heads, 62 sectors/track
Old 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 Linux
New 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 Linux
Warning: partition 4 extends past end of disk
Successfully wrote the new partition table
Re-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 in
2000+0 records out
1024000 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 in
533+1 records out
273172 bytes (273 kB) copied, 1.33912 s, 204 kB/s
9916+0 records in
9916+0 records out
5076992 bytes (5.1 MB) copied, 11.7538 s, 432 kB/s
mke2fs 1.42 (29-Nov-2011)
Filesystem label=data
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
413712 inodes, 1654536 blocks
82726 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1694498816
51 block groups
32768 blocks per group, 32768 fragments per group
8112 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
mke2fs 1.42 (29-Nov-2011)
Filesystem label=system
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
33280 inodes, 132912 blocks
6645 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=138412032
5 block groups
32768 blocks per group, 32768 fragments per group
6656 inodes per group
Superblock backups stored on blocks:
32768, 98304
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
mke2fs 1.42 (29-Nov-2011)
Filesystem label=cache
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
33280 inodes, 132912 blocks
6645 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=138412032
5 block groups
32768 blocks per group, 32768 fragments per group
6656 inodes per group
Superblock backups stored on blocks:
32768, 98304
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
mke2fs 1.42 (29-Nov-2011)
Filesystem label=vender
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
3808 inodes, 15188 blocks
759 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=15728640
2 block groups
8192 blocks per group, 8192 fragments per group
1904 inodes per group
Superblock backups stored on blocks:
8193
Allocating group tables: done
Writing inode tables: done
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done
mke2fs 1.42 (29-Nov-2011)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
3808 inodes, 15188 blocks
759 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=15728640
2 block groups
8192 blocks per group, 8192 fragments per group
1904 inodes per group
Superblock backups stored on blocks:
8193
Allocating group tables: done
Writing inode tables: done
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done
573440+0 records in
573440+0 records out
293601280 bytes (294 MB) copied, 61.2452 s, 4.8 MB/s
10580+0 records in
10580+0 records out
5416960 bytes (5.4 MB) copied, 14.8084 s, 366 kB/s
Author
Tony Liu
2016-8-3, Shenzhen