adb shell mount -o remount,rw /dev/block/mmcblk2p10 /system
sync; sync
adb shell mount -o remount,ro /dev/block/mmcblk2p10 /system

http://www.the-ebook.org/forum/viewtopic.php?t=21458
http://www.sony.net/Products/Linux/Audio/PRS-T1.html

netcfg



# mount
rootfs / rootfs rw 0 0
tmpfs /dev tmpfs rw,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
tmpfs /mnt/shm tmpfs rw,relatime,size=1024k,mode=777,uid=1000,gid=1003 0 0
tmpfs /cache tmpfs rw,relatime,mode=770,uid=1000,gid=2001 0 0
/dev/block/mmcblk2p5 /ebook/fonts cramfs ro,relatime 0 0
/dev/block/mmcblk2p6 /ebook/dic ext4 ro,relatime,barrier=1,data=writeback 0 0
/dev/block/mmcblk2p8 /ebook/preload ext4 ro,relatime,barrier=1,data=writeback 0 0
/dev/block/mmcblk2p10 /system ext4 ro,relatime,barrier=1,data=writeback 0 0
/dev/block/mmcblk2p9 /data ext4 rw,nosuid,nodev,relatime,barrier=1,data=ordered 0 0
/dev/block/vold/179:68 /mnt/sdcard vfat rw,dirsync,nosuid,nodev,noexec,noatime,uid=1000,gid=1015,fmask=0002,dmask=0002,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,batch_sync,utf8,errors=remount-ro 0 0
/dev/block/vold/179:71 /mnt/udisk vfat ro,dirsync,nosuid,nodev,noexec,noatime,fmask=0777,dmask=0777,codepage=cp437,iocharset=iso8859-1,shortname=mixed,batch_sync,utf8,errors=remount-ro 0 0


# cat /proc/cpuinfo
Processor       : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 159.90
Features        : swp half thumb fastmult vfp edsp neon vfpv3
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc08
CPU revision    : 5

Hardware        : Freescale MX50 ARM2 Board
Revision        : 50011
Serial          : 0000000000000000


# busybox free
              total         used         free       shared      buffers
  Mem:       249552       238080        11472            0         7284
 Swap:            0            0            0
Total:       249552       238080        11472


# busybox df -h
Filesystem                Size      Used Available Use% Mounted on
tmpfs                   121.9M     12.0K    121.8M   0% /dev
tmpfs                     1.0M         0      1.0M   0% /mnt/shm
tmpfs                   121.9M         0    121.9M   0% /cache
/dev/block/mmcblk2p5     18.3M     18.3M         0 100% /ebook/fonts
/dev/block/mmcblk2p6    133.9M    133.9M     17.0K 100% /ebook/dic
/dev/block/mmcblk2p8     35.8M     35.8M     11.0K 100% /ebook/preload
/dev/block/mmcblk2p10
                         99.6M     99.5M     99.0K 100% /system
/dev/block/mmcblk2p9     46.5M     38.7M      7.8M  83% /data
/dev/block/vold/179:68
                          1.4G     64.2M      1.3G   4% /mnt/sdcard
/dev/block/vold/179:71
                         10.0M      2.2M      7.8M  22% /mnt/udisk