U-Boot Usage Guide

Burning boot.img Using A Thumbdrive (U-Disk)

Copy the boot.img into a thumbdrive, then plug it into your target device:

kvim# usb_update boot boot.img

Burning boot.img Using An SD-Card

Copy the boot.img to an SD-card, then plug into your target device:

kvim# sdc_update boot boot.img

Erase Partition

kvim# store erase partition boot
kvim# amlmmc erase rootfs


You can get help for U-Boot commands by using the U-Boot help command.

Typing help followed by a command name gives help regarding that particular command:

kvim# help store
store - STORE sub-system

store store init flag
store read name addr off|partition size
read 'size' bytes starting at offset 'off'
to/from memory address 'addr', skipping bad blocks.
store write name addr off|partition size
write 'size' bytes starting at offset 'off'
to/from memory address 'addr', skipping bad blocks.
store rom_write add off size.
write uboot to the boot device
store erase boot/data:
erase the area which is uboot or data
store erase partition <partition_name>:
erase the area which partition in u-boot
store erase dtb
store erase key
store disprotect key
store rom_protect on/off
store scrub off|partition size
scrub the area from offset and size
store dtb iread/read/write addr <size>
read/write dtb, size is optional
store key read/write addr <size>
read/write key, size is optional


Typing help at the U-Boot command prompt gives a list of supported commands:

kvim# help
? - alias for 'help'
aml_sysrecovery- Burning with amlogic format package from partition sysrecovery
amlmmc - AMLMMC sub system
amlnf - aml nand sub-system
amlnf_test- AMLPHYNAND sub-system
autoscr - run script from memory
base - print or set address offset
bmp - manipulate BMP image data
booti - boot arm64 Linux Image image from memory
bootm - boot application image from memory
bootp - boot image via network using BOOTP/TFTP protocol
cbusreg - cbus register read/write
clkmsr - measure PLL clock
cmp - memory compare
cp - memory copy
crc32 - checksum calculation
dcache - enable or disable data cache
defenv_reserv- reserve some specified envs after defaulting env
dhcp - boot image via network using DHCP/TFTP protocol
echo - echo args to console
efuse - efuse read/write data commands
efuse_user- efuse user space read write ops
emmc - EMMC sub system
env - environment handling commands
exit - exit script
ext2load- load binary file from a Ext2 filesystem
ext2ls - list files in a directory (default /)
ext4load- load binary file from a Ext4 filesystem
ext4ls - list files in a directory (default /)
ext4size- determine a file's size
false - do nothing, unsuccessfully
fatinfo - print information about filesystem
fatload - load binary file from a dos filesystem
fatls - list files in a directory (default /)
fatsize - determine a file's size
fdt - flattened device tree utility commands
get_rebootmode- get reboot mode
go - start application at address 'addr'
gpio - query and control gpio pins
hdmitx - HDMITX sub-system
help - print command description/usage
i2c - I2C sub-system
icache - enable or disable instruction cache
imgread - Read the image from internal flash with actual size
itest - return true/false on integer compare
jtagoff - disable jtag
jtagon - enable jtag
keyman - Unify key ops interfaces based dts cfg
keyunify- key unify sub-system
loop - infinite loop on address range
macreg - ethernet mac register read/write/dump
md - memory display
mm - memory modify (auto-incrementing address)
mmc - MMC sub system
mmcinfo - display MMC info
mw - memory write (fill)
mwm - mw mask function
nm - memory modify (constant address)
open_scp_log- print SCP messgage
osd - osd sub-system
phyreg - ethernet phy register read/write/dump
ping - send ICMP ECHO_REQUEST to network host
printenv- print environment variables
rarpboot- boot image via network using RARP/TFTP protocol
read_temp- cpu temp-system
reboot - set reboot mode and reboot system
reset - Perform RESET of the CPU
rsvmem - reserve memory
run - run commands in an environment variable
saveenv - save environment variables to persistent storage
sdc_burn- Burning with amlogic format package in sdmmc
sdc_update- Burning a partition with image file in sdmmc card
set_trim_base- cpu temp-system
set_usb_boot- set usb boot mode
setenv - set environment variables
showvar - print local hushshell variables
silent - silent
sleep - delay execution for some time
store - STORE sub-system
systemoff- system off
temp_triming- cpu temp-system
test - minimal test like /bin/sh
tftpboot- boot image via network using TFTP protocol
true - do nothing, successfully
unpackimg- un pack logo image into pictures
update - Enter v2 usbburning mode
usb - USB sub-system
usb_burn- Burning with amlogic format package in usb
usb_update- Burning a partition with image file in usb host
usbboot - boot from USB device
version - print monitor, compiler and linker version
vout - VOUT sub-system
vpu - vpu sub-system
write_trim- cpu temp-system
write_version- cpu temp-system