You can not use fastboot on ODROID-XU4, because It doesn't have USB otg port.
How to write images?
First! setup adb connection or copy image to fat partition.
http://codewalkerster.blogspot.kr/2015/07/adb-connect-over-tcpip-when-multiple.html
Push image to fat partition.
$ adb push xxxx.img /storage/sdcard0/
$ adb reboot
Enter u-boot prompt.
U-Boot 2012.07-00029-g0e9204d-dirty (Jul 17 2015 - 15:38:42) for Exynos5422
CPU: Exynos5422 Rev0.1 [Samsung SOC on SMP Platform Base on ARM CortexA7]
APLL = 800MHz, KPLL = 800MHz
MPLL = 532MHz, BPLL = 825MHz
Board: HardKernel ODROID
DRAM: 2 GiB
WARNING: Caches not enabled
TrustZone Enabled BSP
BL1 version: �/� ⁁
VDD_KFC: 0x44
LDO19: 0xf2
Checking Boot Mode ... SDMMC
MMC: S5P_MSHC2: 0, S5P_MSHC0: 1
MMC Device 0: 7.4 GiB
MMC Device 1: [ERROR] response timeout error : 00000104 cmd 1
Card did not respond to voltage select!
*** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
Net: No ethernet found.
Double Press 'Enter' to stop autoboot: 0
Exynos5422 #
Example for zImage-dtb
Exynos5422 #
fatload mmc 0:1 40008000 zImage-dtb
there are pending interrupts 0x00000001
reading zImage-dtb
4718814 bytes read
Exynos5422 #
movi write kernel 0 40008000
writing kernel..device 0 Start 1263, Count 16384
MMC write: dev # 0, block # 1263, count 16384 ... 16384 blocks write: OK
completed
Exynos5422 #
Example for system.img
Exynos5422 # fatload mmc 0:1 40000000 system.img
there are pending interrupts 0x00000001
reading system.img
355139392 bytes read
Exynos5422 # fastboot flash system 40000000 0
[Partition table on MoviNAND]
ptn 0 name='fwbl1' start=0x0 len=N/A (use hard-coded info. (cmd: movi))
ptn 1 name='bl2' start=N/A len=N/A (use hard-coded info. (cmd: movi))
ptn 2 name='bootloader' start=N/A len=N/A (use hard-coded info. (cmd: movi))
ptn 3 name='tzsw' start=N/A len=N/A (use hard-coded info. (cmd: movi))
ptn 4 name='kernel' start=N/A len=N/A (use hard-coded info. (cmd: movi))
ptn 5 name='ramdisk' start=N/A len=0x800000(~8192KB) (use hard-coded info. (cmd)
ptn 6 name='system' start=0x42B5800 len=0x40648800(~1055010KB)
ptn 7 name='userdata' start=0x448FE000 len=0x80527800(~2102430KB)
ptn 8 name='cache' start=0xC4E25800 len=0x1036C800(~265650KB)
ptn 9 name='fat' start=0xD5192000 len=0x1002E5800(~4197270KB)
flashing 'system'
Compressed ext4 image
*** erase start block 0x215ac ***
*** erase block length 0x202ff0 ***
mmc erase user 0 21800 202c00
MMC erase: dev # 0, block # 137216, count 2108416 ... START: 137216 BLOCK: 21086
high_capacity: 1
Capacity: 2
byte_addressing
before_send_cmd
start_addr
end_addr
erase_addr
Erase
........................................
........................................
........................................
........................................
........................................
..........
1.0 GB erase Done
2108416 blocks erase: OK
MMC write: dev # 0, block # 136620, count 8 ... 8 blocks write: OK
MMC write: dev # 0, block # 136628, count 8 ... 8 blocks write: OK
MMC write: dev # 0, block # 136636, count 504 ... 504 blocks write: OK
......
.....
You can find other command to write image in this boot.ini files.
boot.ini for eMMC
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
#------------------------------------------------------------------------------------------------------
#
# EMMC to EMMC Recovery boot.ini text file
#
#------------------------------------------------------------------------------------------------------
ODROIDXU-UBOOT-CONFIG
#------------------------------------------------------------------------------------------------------
# BL1 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl1.bin
emmc open 0
movi w z f 0 40008000
emmc close 0
#------------------------------------------------------------------------------------------------------
# BL2 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl2.bin
emmc open 0
movi w z b 0 40008000
emmc close 0
#------------------------------------------------------------------------------------------------------
# Bootloader write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 u-boot.bin
emmc open 0
movi w z u 0 40008000
emmc close 0
#------------------------------------------------------------------------------------------------------
# Turst Zone Soft Ware write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 tzsw.bin
emmc open 0
movi w z t 0 40008000
emmc close 0
#------------------------------------------------------------------------------------------------------
# UBOOT ENV Erase
#------------------------------------------------------------------------------------------------------
mmc write 0 40008000 0x4CF 0x20
#------------------------------------------------------------------------------------------------------
# Kernel Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 zImage-dtb
movi write kernel 0 40008000
#------------------------------------------------------------------------------------------------------
# System Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40000000 system.img
#------------------------------------------------------------------------------------------------------
# Userdata Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 57000000 userdata.img
#------------------------------------------------------------------------------------------------------
# Cache Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 61000000 cache.img
#------------------------------------------------------------------------------------------------------
# Partition Create to eMMC
#------------------------------------------------------------------------------------------------------
fdisk -c 0
#------------------------------------------------------------------------------------------------------
fastboot flash system 40000000 0
fastboot flash userdata 57000000 0
fastboot flash cache 61000000 0
#------------------------------------------------------------------------------------------------------
# SD/eMMC FAT Format
#------------------------------------------------------------------------------------------------------
fatformat mmc 0:1
reset
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
boot.ini for SD
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
#------------------------------------------------------------------------------------------------------
#
# SD to SD Recovery boot.ini text file
#
#------------------------------------------------------------------------------------------------------
ODROIDXU-UBOOT-CONFIG
#------------------------------------------------------------------------------------------------------
# BL1 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl1.bin
movi w f 0 40008000
#------------------------------------------------------------------------------------------------------
# BL2 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl2.bin
movi w b 0 40008000
#------------------------------------------------------------------------------------------------------
# Bootloader write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 u-boot.bin
movi w u 0 40008000
#------------------------------------------------------------------------------------------------------
# Turst Zone Soft Ware write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 tzsw.bin
movi w t 0 40008000
#------------------------------------------------------------------------------------------------------
# UBOOT ENV Erase
#------------------------------------------------------------------------------------------------------
mmc write 0 40008000 0x4CF 0x20
#------------------------------------------------------------------------------------------------------
# Kernel Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 zImage-dtb
movi write kernel 0 40008000
#------------------------------------------------------------------------------------------------------
# System Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40000000 system.img
#------------------------------------------------------------------------------------------------------
# Userdata Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 57000000 userdata.img
#------------------------------------------------------------------------------------------------------
# Cache Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 61000000 cache.img
#------------------------------------------------------------------------------------------------------
# Partition Create to eMMC
#------------------------------------------------------------------------------------------------------
fdisk -c 0
#------------------------------------------------------------------------------------------------------
fastboot flash system 40000000 0
fastboot flash userdata 57000000 0
fastboot flash cache 61000000 0
#------------------------------------------------------------------------------------------------------
# SD/eMMC FAT Format
#------------------------------------------------------------------------------------------------------
fatformat mmc 0:1
reset
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
boot.ini for SD to eMMC
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
#------------------------------------------------------------------------------------------------------
#
# EMMC to EMMC Recovery boot.ini text file
#
#------------------------------------------------------------------------------------------------------
ODROIDXU-UBOOT-CONFIG
#------------------------------------------------------------------------------------------------------
# BL1 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl1.bin
emmc open 1
movi w z f 1 40008000
emmc close 1
#------------------------------------------------------------------------------------------------------
# BL2 write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 bl2.bin
emmc open 1
movi w z b 1 40008000
emmc close 1
#------------------------------------------------------------------------------------------------------
# Bootloader write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 u-boot.bin
emmc open 1
movi w z u 1 40008000
emmc close 1
#------------------------------------------------------------------------------------------------------
# Turst Zone Soft Ware write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 tzsw.bin
emmc open 1
movi w z t 1 40008000
emmc close 1
#------------------------------------------------------------------------------------------------------
# UBOOT ENV Erase
#------------------------------------------------------------------------------------------------------
mmc write 1 40008000 0x4CF 0x20
#------------------------------------------------------------------------------------------------------
# Kernel Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40008000 zImage-dtb
movi write kernel 1 40008000
#------------------------------------------------------------------------------------------------------
# System Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 40000000 system.img
#------------------------------------------------------------------------------------------------------
# Userdata Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 57000000 userdata.img
#------------------------------------------------------------------------------------------------------
# Cache Image write to eMMC
#------------------------------------------------------------------------------------------------------
fatload mmc 0:1 61000000 cache.img
#------------------------------------------------------------------------------------------------------
# Partition Create to eMMC
#------------------------------------------------------------------------------------------------------
fdisk -c 1
#------------------------------------------------------------------------------------------------------
fastboot flash system 40000000 1
fastboot flash userdata 57000000 1
fastboot flash cache 61000000 1
#------------------------------------------------------------------------------------------------------
# SD/eMMC FAT Format
#------------------------------------------------------------------------------------------------------
fatformat mmc 1:1
fastboot poweroff
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Build android.
$ adb connect 192.168.x.x
$ cd out/target/products/odroidxu3/
$ adb push update.zip /storage/sdcard0/
$ adb push update.zip.md5sum /storage/sdcard0/
Run ODROID Update.
Now enable 'Validate file' button.
