I am having difficulty getting wifi working when I build my own kernel and rootfs. No matter what I try I can't seem to get the wifi on the dragonboard to start up! I suspect it's something to do with the filesystem, and not having the wcn36xx-platform-tools.ko file based on a post on this forum - but I'm not sure.
I am using the following process to create the kernel and filesystem:
1 - using kernel 4.4.23 downloaded from linaro and using the defconfig provided. In this I can see that the wcn36xx support is selected as a LKM, but I have tried it built into the kernel too (I have also tired it building the kernel manually as described on the linaro download page).
2 - using buildroot tell it to build the kernel from my local source, from step 1. The file system is configured to use minimal 'stuff': busybox and that's about it!
3 - Using the initramfs, dt.img provided by linaro use the mkbootimg tool on my new kernel source.
4 - dcfldd the kernel and the rootfs into their respective sections of the SD card.
On the dragonboard:
5 - After booting the dragonboard I can see that it's my new kernel through the uname command, and that it's my new filesystem because of the custom login message.
6 - using ifconfig I can only see the lo interface.
If the wifi support in the kernel build was specified as a LKM I can navigate to /lib/modules/4.4.23/kernel/drivers/wireless/ath/wcn23xx and see the file wcn36xx.ko present
I have got the latest BSP from qcom, but I'm not sure what to do with this, so it could be that I'm not using it? Though I always thought that was part of the kernel source provided by Linaro.
Can anybody point me in the right direction to get it up and running? I suspect it's a quick thing that I'm forgetting or not aware of in how to port Linux.