Booting release image with bootusb
 - Use this if you are flashing image from macos/flashusb.sh
```
setenv bootusb '
usb start;
setenv kernel_addr_r 0xa0000000;
ext4load usb 0:2 ${kernel_addr_r} /boot/kernel.itb;
bootm ${kernel_addr_r};
'

run bootusb
```

Booting into initramfs (board.itb in usb drive root)
```
setenv bootusb 'usb start; ext4load usb 0:2 ${mks_loadaddr} /boot/kernel.itb; bootm ${mks_loadaddr}'
run bootusb
```


Original uboot env from mono
```
arch=arm
baudrate=115200
board=gateway_dk
board_name=gateway_dk
bootargs_console=console=ttyS0,115200 earlycon=uart8250,mmio,0x21c0500 mtdparts=${mtdparts}
bootcmd=run emmc || run recovery
bootdelay=5
cpu=armv8
emmc=setenv bootargs "${bootargs_console} root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 ${bootargs_hwtest}"; \
    ext4load mmc 0:1 ${kernel_addr_r} /boot/Image.gz && \
    ext4load mmc 0:1 ${fdt_addr_r} /boot/mono-gateway-dk-sdk.dtb && \
    booti ${kernel_addr_r} - ${fdt_addr_r} || \
    ext4load mmc 0:1 ${kernel_addr_r} /boot/kernel.itb && \
    bootm ${kernel_addr_r}
eth1addr=E8:F6:D7:00:1E:93
eth2addr=E8:F6:D7:00:1E:94
eth3addr=E8:F6:D7:00:1E:95
eth4addr=E8:F6:D7:00:1E:96
ethact=fm1-mac5
ethaddr=E8:F6:D7:00:1E:92
ethprime=fm1-mac5
fdt_addr=0x500000
fdt_addr_r=0x88000000
fdt_size=0x100000
fdtcontroladdr=fbc01220
fman_ucode=fbc12d40
fsl_bootcmd_mcinitcmd_set=y
kernel_addr=0xA00000
kernel_addr_r=0x82000000
kernel_comp_addr_r=0x90000000
kernel_comp_size=0x1600000
kernel_size=0x1600000
load_addr=0xa0000000
loadaddr=0xa0000000
mks_loadaddr=0x80000000
model=Mono Gateway Development Kit
mtdparts=1550000.spi:1M(rcw-bl2),2M(uboot),1M(uboot-env),1M(fman-ucode),1M(recovery-dtb),4M(unallocated),-(kernel-initramfs)
netmask=255.255.255.0
ramdisk_addr_r=0x88080000
recovery=setenv bootargs "${bootargs_console} rw rootwait quiet ${bootargs_hwtest}"; sf probe 0:0; sf read ${kernel_addr_r} ${kernel_addr} ${kernel_size}; sf read ${fdt_addr_r} ${fdt_addr} ${fdt_size}; booti ${kernel_addr_r} - ${fdt_addr_r}
serial_number=MT-R01A-0326-00747
soc=fsl-layerscape
stderr=serial@21c0500
stdin=serial@21c0500
stdout=serial@21c0500
vendor=freescale
```