Compile

For ipq6018, uboot run in 32-bit mode, compile ipq6018 uboot by ipq40xx toolchain.

clone sdk, ie. toolchain to compile uboot:

git clone https://github.com/gl-inet-builder/openwrt-sdk-ipq_ipq40xx-qsdk11 sdk32

update and install feeds

cd sdk32
./scripts/feeds update -a
./scripts/feeds install -a

Manuall copy https://github.com/gl-inet-builder/qsdk11_feeds/tree/master/qca/feeds/bootloader/uboot-qca-ipq6018 uboot package definition to sdk32/package/ directory is also okay, if you not prefer to update feeds.

clone uboot source code

cd qca/src/
git clone https://github.com/gl-inet/uboot-ipq60xx.git u-boot-2016
cd ../..

compile uboot

make package/feeds/base/uboot-qca-ipq6018/compile V=s

To fix error build

ERROR:root:code for hash sha1 was not found.

edit apt source: /etc/apt/sources.list to add

deb http://security.ubuntu.com/ubuntu bionic-security main

Then install libssl1.0-dev

sudo apt update && apt-cache policy libssl1.0-dev
sudo apt-get install libssl1.0-dev

the uboot binary will be: bin/ipq/openwrt-ipq6018-u-boot.mbn