Building LEDE / Openwrt for x86

Wed, May 10, 2017

EDIT: 2018-03-12, LEDE and Openwrt have merged. References to LEDE here can be substituted for Openwrt.

I had a need to run LEDE on x86 hardware. Building a custom LEDE seemed a bit daunting at first, but turned out to be quite straight forward. The build described here is tailored for Qotom J1900 mini PC.

Building the custom image

I chose to build the LEDE x86_64 image within a Docker container like so:

$ docker pull centos
$ docker run -it centos /bin/bash
<container>$ cd root/
<container>$ yum install wget make gcc openssl which xz perl zlib-static ncurses-devel perl-Thread-Queue.noarch gcc-c++ git file unzip bzip2
<container>$ wget https://downloads.lede-project.org/releases/17.01.1/targets/x86/64/lede-imagebuilder-17.01.1-x86-64.Linux-x86_64.tar.xz
<container>$ tar -xvJf lede-imagebuilder-17.01.1-x86-64.Linux-x86_64.tar.xz
<container>$ cd lede-imagebuilder-17.01.1-x86-64.Linux-x86_64

Build the image. I want USB keyboard support, and don’t need e1000 or realtek drivers

 make image packages="-kmod-e1000e -kmod-e1000 -kmod-r8169 kmod-usb-hid kmod-usb3 kmod-usb2"

The new images are located under ./bin/targets/x86/64 inside the build environment

# ls -l bin/x86/64
total 35852
-rw-r--r--. 1 root root  5587318 May  9 20:36 lede-17.01.1-x86-64-combined-ext4.img.gz
-rw-r--r--. 1 root root 19466174 May  9 20:36 lede-17.01.1-x86-64-combined-squashfs.img
-rw-r--r--. 1 root root  2439806 May  9 20:36 lede-17.01.1-x86-64-generic-rootfs.tar.gz
-rw-r--r--. 1 root root     1968 May  9 20:36 lede-17.01.1-x86-64-generic.manifest
-rw-r--r--. 1 root root  2711691 May  9 20:36 lede-17.01.1-x86-64-rootfs-ext4.img.gz
-rw-r--r--. 1 root root  2164670 May  9 20:36 lede-17.01.1-x86-64-rootfs-squashfs.img
-rw-r--r--. 1  106  111  2620880 Apr 17 17:53 lede-17.01.1-x86-64-vmlinuz
-rw-r--r--. 1 root root      731 May  9 20:36 sha256sums

Just need the combined-ext4 image. Copy that out from the docker container to USB flash drive:

$ docker cp <container id>:/root/lede-imagebuilder-17.01.1-x86-64.Linux-x86_64/bin/targets/x86/64/lede-17.01.1-x86-64-combined-ext4.img.gz /mnt

Installing the custom image

boot the mini PC using any Linux rescue disk. (I used SystemRescueCD)
insert a second USB flash disk containing the image created above
write the image to the mini PC internal drive:

$ mount /dev/sdc1 /mnt; cd /mnt
$ gunzip lede-17.01.1-x86-64-combined-ext4.img.gz
$ dd if=lede-17.01.1-x86-64-combined-ext4.img.gz of=/dev/sda

(optionally) resize the LEDE data partition to fill the entire size of the internal storage
use fdisk/parted to remove second partition (/dev/sda2)
re-add second partition with the same starting block as before, but make the end block the last block on the disk
save the new partition table
run e2fsck -f /dev/sda2 followed by resize2fs /dev/sda2
reboot the device
access the console via VGA console, or telnet to IP 192.168.1.1 (no root password!)