I recently installed NetBSD/amd64 10.1 on my ThinkPad T400, but I am having issues with WiFi.

My WiFi card is supported by the iwn(4) driver, and it worked just fine in the installer; but when when booting, I get this error in my dmesg:

[   170.004879] iwn0: autoconfiguration error: could not get firmware handle iwlwifi-5000-2.ucode  
[   170.004879] iwn0: autoconfiguration error: could not read firmware  
[   762.464956] iwn0: autoconfiguration error: could not get firmware handle iwlwifi-5000-2.ucode  
[   762.464956] iwn0: autoconfiguration error: could not read firmware  

When I try to start networking manually, I get this:

amethyst# sh /etc/rc.d/network start  
Starting network.  
Hostname: amethyst.fritz.box  
IPv6 mode: host  
Configuring network interfaces: iwn0ifconfig: exec_matches: No such file or directory  
.  
Adding interface aliases:.  
Waiting for duplicate address detection to finish...  

And I can confirm that the file does exist in the correct location:

amethyst# file /libdata/firmware/if_iwn/iwlwifi-5000-2.ucode  
lhs/off overflow 4270589976 0  
/libdata/firmware/if_iwn/iwlwifi-5000-2.ucode: data  

Does anyone have any idea how to fix this?

SOLUTION!!!

I am using a cgdroot, which I did not realise was related.

As I understand it, the firmware needs to be loaded during boot; but when rc(8) is looking for /libdata/firmware, the firmware is actually in /altroot/libdata/firmware.

To fix, add this to your sysctl.conf:

hw.firmware.path=/altroot/libdata/firmware:/altroot/usr/libdata/firmware:/altroot/usr/pkg/libdata/firmware:/altroot/usr/pkg/libdata

(Note: Run sysctl hw.firmware.path first and check the output, in case the firmware path changes in the future)