fastboot on ASUS MeMO PAD 8/10

enter fastboot mode

by VOL- key

plug USB, power off, press & hold VOL-, then power on
or
unplug USB, power off, press & hold VOL-, then plug USB

by adb

adb reboot bootloader

fastboot oem log

(bootloader) arch_interrupt_init
(bootloader) SdmmcInit=2 0
(bootloader) FwPartOffset=2000 , 0
(bootloader) emmc init OK!
(bootloader) Using default environment
(bootloader) 
(bootloader) SPI init ok ~ 
(bootloader) In:    serial
(bootloader) Out:   serial
(bootloader) Err:   serial
(bootloader) board_late_init
(bootloader) SecureBootEn = 1 0
(bootloader) ##################################################
(bootloader) 
(bootloader) #Boot ver: 2013-10-17#0.02
(bootloader) 
(bootloader) ##################################################
(bootloader) TIME : 24 - 01:18:08 
(bootloader) GetParam
(bootloader) check parameter success
(bootloader) partition(misc): offset=0x00002000, size=0x00002000
(bootloader) partition(kernel): offset=0x00004000, size=0x00004000
(bootloader) partition(boot): offset=0x00008000, size=0x00008000
(bootloader) partition(recovery): offset=0x00010000, size=0x00010000
(bootloader) partition(backup): offset=0x00020000, size=0x00020000
(bootloader) partition(system): offset=0x00040000, size=0x00300000
(bootloader) partition(cache): offset=0x00340000, size=0x000FC000
(bootloader) partition(adf): offset=0x0043C000, size=0x00004000
(bootloader) partition(apd): offset=0x00440000, size=0x00100000
(bootloader) partition(kpanic): offset=0x00540000, size=0x00002000
(bootloader) partition(hidden): offset=0x00542000, size=0x00002000
(bootloader) partition(userdata): offset=0x00544000, size=0xFFFFFFFF
(bootloader) empty serial no.
(bootloader) UBS is connected !
(bootloader) mode_priority should be 4 
(bootloader) vbus = 1
(bootloader) battery id = 0 
(bootloader) PONHIS = 0x4 
(bootloader) POFFHIS = 0x10 
(bootloader) pwron_reason = 4 
(bootloader) mode_priority = 4 
(bootloader) Battery Voltage is 4097mV 
(bootloader) xxxx LCD AUO !
(bootloader) lcd_ctrl_init [38]
(bootloader) rk_fb_init  ok!
(bootloader) set_lcdc_dclk: lcdc_source_clk = 768, clk = 80, div = 9
(bootloader) xxxx LCD AUO !
(bootloader) lcd_enable [58]
OKAY [  0.050s]
finished. total time: 0.050s

it may need to be run just after boot, otherwise it may fail

  :
FAILED (status read failed (Value too large for defined data type))
finished. total time: 5.041s

enter Rockchip bootloader mode

fastboot reboot-bootloader

unlock fastboot flash command

if you just want to make a backup, install custom roms, and/or something else, then CWM-based recovery will be enough for you. unlocking is not needed. it's not recommended.

if you really want to unlock fastboot (for what?), you should (at least) make a backup of first 4MiB area of eMMC by following command.

dd if=/dev/block/mmcblk0 of=/sdcard/mmcblk0-head.img bs=4194304 count=1

fastboot oem unlock61646
fastboot oem unlockD696E

(re)lock fastboot flash command

fastboot oem lock