openwrt . Ventoy

Ventoy Boot OpenWrt

Background

Ventoy supports OpenWrt since 1.0.41, but it needs some special treatment which is explained here.
Note: You should confirm that the IMG file can boot fine when you burn it directly to the USB.
If it can't boot even you directly burn it to the USB, then it may not be a Ventoy issue.

ventoy_openwrt.xz plugin

Since some kernel modules required by Ventoy are not included in the OpenWrt IMG file at present.
So it is necessary to download the ventoy_openwrt.xz and put it in the USB stick.
This plugin actually packs the kernel module files on the OpenWrt official website. Download it here:
https://github.com/ventoy/OpenWrtPlugin/releases

Note that this plugin may be updated for new OpenWrt release, please keep using the latest release.

Create a ventoy directory in the root of the 1st partition(the partition with bigger capacity and is also where the ISO files locate) and put the file under the directory.
Attention:
1. The directory name ventoy must be all lowercase letters.
2. The 1st partition has a label Ventoy (the first letter is in UPPERCASE), some distro will auto mount the partition (e.g. /dev/sdb1) to /mnt/Ventoy
If so, don't confuse the label and the directory. You need to create the ventoy directory under /mnt/Ventoy which is /mnt/Ventoy/ventoy

Supported IMG type

Ventoy only supports x86 combined-ext4.img and combined-squashfs.img file.
For combined-ext4.img, you just need to download the gzip file from the website, decompress it and copy it to Ventoy USB.
For combined-squashfs.img, you need some special process as follows:

combined-squashfs.img

After download combined-squashfs.img from the website, you need to run ventoy_openwrt_squashfs.sh script to make some process for the img file.
This script file is also included in the above link as the ventoy_openwrt.xz plugin. Usage:

sh ventoy_openwrt_squashfs.sh  openwrt-xxx-combined-squashfs.img.gz

For example:
sh ventoy_openwrt_squashfs.sh  openwrt-19.07.7-x86-64-combined-squashfs.img.gz

In the example, the script will create a openwrt-19.07.7-x86-64-combined-squashfs.img file. Copy it to the Ventoy USB and boot it.