.TH DTMERGE 1
.
.SH NAME
dtmerge \- merge an overlay or parameters into a base device-tree
.
.
.SH SYNOPSIS
.SY dtmerge
.OP \-d
.I base-dtb
.I merged-dtb
.I overlay-dtb
.RI [ param=val \|.\|.\|.]
.YS
.
.SY dtmerge
.B \-h
.YS
.
.
.SH DESCRIPTION
.B dtmerge
is a command line utility for merging overlays and/or device-tree parameters
with a base device-tree.
See
.B [DTREE]
for more information.
.
.PP
The base device-tree (in dtb format) is always specified as the first
(non-option) argument.
The second argument is the output filename, which will also be in dtb format.
The third argument provides the name of the overlay to merge into the base
tree.
If this is "-" then no overlay is used and the utility will simply customize
the base tree with any parameters given.
.
.
.SH OPTIONS
.
.TP
.BR \-d
Show debug output during operation.
.
.TP
.BR \-h
Displays help on the application.
.
.
.SH EXAMPLES
.
.TP
.B dtmerge /boot/bcm2711-rpi-4-b.dtb out.dtb - spi=on i2c=on
Produce a device-tree for the Raspberry Pi 4 in "out.dtb" which has the SPI and
I2C interfaces activated.
.
.TP
.B dtmerge /boot/bcm2710-rpi-3-b-plus.dtb out.dtb /boot/overlays/gpio-shutdown.dtbo
Produce a device-tree for the Raspberry Pi 3+ in "out.dtb" which includes the
GPIO shutdown overlay (with all parameters set to their default).
.
.
.SH SEE ALSO
.BR dtoverlay (1),
.BR dtparam (1),
.B [DTREE]
.
.
.SH REFERENCES
.TP
.B [DTREE]
https://www.raspberrypi.org/documentation/configuration/device-tree.md