U-boot commands: Difference between revisions
From embeddedTS Manuals
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(fixed an off-by-one error in gpio expression, added clarification text to gpio calculation.) |
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# for more GPIO support. | # for more GPIO support. | ||
# GPIO are specified in bank and IO in this manual. U-Boot uses a flat numberspace, | # GPIO are specified in bank and IO in this manual. U-Boot uses a flat numberspace, | ||
# so for bank 2 DIO 25, this would be number (32* | # so for bank 2 DIO 25, this would be number (32*1)+25=89 | ||
# The formula thus being (32*(bank-1)+dio)=flattened_dio | |||
# Note that on some products, bank 1 is the first bank | # Note that on some products, bank 1 is the first bank | ||
# Set 2_25 low | # Set 2_25 low |
Latest revision as of 17:21, 6 January 2021
# The most important command is
help
# This can also be used to see more information on a specific command
help i2c
# This is a command added to U-Boot by TS to read the baseboard ID on our
# System on Module devices
bbdetect
echo ${baseboard} ${baseboardid}
# The echo will return something similar to:
# TS-8390 2
# Boots into the binary at $loadaddr. The loaded file needs to have
# the U-Boot header from mkimage. A uImage already contains this.
bootm
# Boots into the binary at $loadaddr, skips the initrd, specifies
# the FDT addrress so Linux knows where to find the device tree
bootm ${loadaddr} - ${fdtaddr}
# Boot a Linux zImage loaded at $loadaddr
bootz
# Boot in to a Linux zImage at $loadaddr, skip initrd, specifies
# the FDT address to Linux knows where to find the device tree
bootz ${loadaddr} - ${fdtaddr}
# Get a DHCP address
dhcp
# This sets ${ipaddr}, ${dnsip}, ${gatewayip}, ${netmask}
# and ${ip_dyn} which can be used to check if the dhcp was successful
# These commands are used for scripting:
false # do nothing, unsuccessfully
true # do nothing, successfully
# This command can set fuses in the processor
# Setting fuses can brick the unit, will void the warranty,
# and should not be done in most cases
fuse
# GPIO can be manipulated from U-Boot. Keep in mind that the IOMUX
# in U-Boot is only setup enough to boot the device, so not all pins will
# be set to GPIO mode out of the box. Boot to the full operating system
# for more GPIO support.
# GPIO are specified in bank and IO in this manual. U-Boot uses a flat numberspace,
# so for bank 2 DIO 25, this would be number (32*1)+25=89
# The formula thus being (32*(bank-1)+dio)=flattened_dio
# Note that on some products, bank 1 is the first bank
# Set 2_25 low
gpio clear 83
# Set 2_25 high
gpio set 83
# Read 2_25
gpio input 83
# Control LEDs
led red on
led green on
led all off
led red toggle
# This command is used to copy a file from most devices
# Load kernel from SD
load mmc 0:1 ${loadaddr} /boot/uImage
# Load Kernel from eMMC
load mmc 1:1 ${loadaddr} /boot/uImage
# Load kernel from USB
usb start
load usb 0:1 ${loadaddr} /boot/uImage
# Load kernel from SATA
sata init
load sata 0:1 ${loadaddr} /boot/uImage
# View the FDT from U-Boot
load mmc 0:1 ${fdtaddr} /boot/imx6q-ts4900.dtb
fdt addr ${fdtaddr}
fdt print
# It is possible to blindly jump to any memory location
# This is similar to bootm, but it does not require
# the use of the U-Boot header
load mmc 0:1 ${loadaddr} /boot/custombinary
go ${loadaddr}
# Browse fat, ext2, ext3, or ext4 filesystems:
ls mmc 0:1 /
# Access memory like devmem in Linux, read/write arbitrary memory
# using mw and md
# write
mw 0x10000000 0xc0ffee00 1
# read
md 0x10000000 1
# Test memory.
mtest
# Check for new SD card
mmc rescan
# Read SD card size
mmc dev 0
mmcinfo
# Read eMMC Size
mmc dev 1
mmcinfo
# The NFS command is like 'load', but used over the network
dhcp
env set serverip 192.168.0.11
nfs ${loadaddr} 192.168.0.11:/path/to/somefile
# Test ICMP
dhcp
ping 192.168.0.11
# Reboot
reset
# SPI access is through the SF command
# Be careful with sf commands since
# this is where U-Boot and the FPGA bitstream exist
# Improper use can render the board unbootable
sf probe
# Delay in seconds
sleep 10
# Load HUSH scripts that have been created with mkimage
load mmc 0:1 ${loadaddr} /boot/ubootscript
source ${loadaddr}
# Most commands have return values that can be used to test
# success, and HUSH scripting supports comparisons like
# test in Bash, but much more minimal
if load mmc 1:1 ${fdtaddr} /boot/uImage;
then echo Loaded Kernel
else
echo Could not find kernel
fi
# Commands can be timed with "time"
time sf probe
# Print U-Boot version/build information
version