How to add custom drivers

[abhiyee]

How to compile custom drivers from source

**I own a RTL8821AU Based wifi adapter. The adapter detects in the alpine environment after giving the usb permissions (verified with lsusb) but it didn't get registered as a network interface. So in order to compile the driver it needs full kernel headers which i doesn't got and failed the compilation **
So can someone help me to do this?

[ExTV]

You should not need to compile anything. The driver for that adapter is already built into the Podroid kernel: CONFIG_RTW88_8821AU=y, along with 8812AU and 8814AU. I confirmed it on a current build by reading /proc/config.gz inside the guest.

What is missing is firmware. The guest image ships none, so the adapter enumerates (which is why lsusb sees it) and then the driver cannot load its firmware, so no network interface ever appears. Install it in the guest and replug the adapter:

apk add linux-firmware-rtw88

If it still does not come up, run dmesg | grep -i rtw right after plugging it in. That will show whether it is a firmware load failure or something else, and it is worth posting here.

On the general question of custom drivers: there is no way to build kernel modules inside the guest. The kernel is built with everything in-tree and ships no modules and no headers, so /lib/modules does not exist. Adding a driver means enabling it in the kernel config and rebuilding the kernel, which happens in this repo. If you have hardware that needs something not enabled yet, open an issue with the USB id from lsusb and I will look at enabling it.