chowderhead

I'll try another question: How do I determine what linux kernels are available from Armbian? There are a few versions of preempt rt patches, e.g., patch-5.4.61-rt37 and patch-4.19.142-rt63, but I have no idea how to find their matching kernels short of setting KERNELBRANCH and learning compile fails when I run it.

I'm a complete noob to compiling kernels and have been struggling (and failing) for the past week to get an RT kernel compiled using Armbian build and reading various threads in the forum. Is it even possible? If so, what config options need to be set to get the correct kernel version matching the available rt patches? Thanks!

Thanks ag123 - the link to the other post did the trick. Didn't need to try the other dtc compiler. In case someone else is doing the same thing: Decompile the dtb in /boot/dtb. In the case of the Orange Pi Zero, it's sun8i-h2-plus-orangepi-zero.dtb: dtc -I dtb -O dts sun8i-h2-plus-orangepi-zero.dtb -o sun8i-h2-plus-orangepi-zero.dts The original dtb had no clock frequency entries for any of the i2c buses: i2c0 (i2c@01c2ac00), i2c1 (i2c@01c2b000) and i2c2 (i2c@01c2b400). Add a line to the i2c@01c2b000 (i2c) section (or whichever bus you're wishing to change): clock-frequency = <0x61A80>; Recompile the dts: dtc -I dts -O dtb sun8i-h2-plus-orangepi-zero.dts -o sun8i-h2-plus-orangepi-zero.dtb Reboot.

4.14.65-sunxi on an Orange Pi Zero. Trying to set the i2c bus speed to 400kHz using the following dts: /dts-v1/; /plugin/; / { compatible = "allwinner,sun8i-h3"; fragment@0 { target = <&i2c0>; __overlay__ { clock-frequency = <400000>; }; }; }; Which produces: Error: dtc does not support compiling overlays Please try to install matching kernel headers Installed linux-headers-next-sunxi and still getting the same thing. Device tree compiler version: DTC 1.4.2. What am I doing wrong?

Thanks, Igor. Wijnen is offering to help, but nobody responded to his request, so you're missing an opportunity:

So I followed the advise given and purchased an Orange Pi Zero Plus2 H3. No luck. Steps followed: Removed network-manager (doesn't work with hostapd so I don't need it). Permit ipv4 forwarding by uncommenting net.ipv4.ip_forward=1 in /etc/sysctl.conf. Setup dnsmasq to serve dhcp over wlan0_ap and ignore wlan0. Create virtual device wlan0_ap: iw dev wlan0 interface add wlan0_ap type managed /etc/network/interfaces: auto lo iface lo inet loopback auto wlan0 iface wlan0 inet dhcp wpa-essid "myssid" wpa-psk "mypassphrase" auto wlan0_ap iface wlan0_ap inet static address 192.168.76.1 netmask 255.255.255.0 /etc/hostapd/hostapd.conf: interface=wlan0_ap ssid=opi0plus2 hw_mode=g channel=4 macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=2 wpa_passphrase=0123456789 wpa_key_mgmt=WPA-PSK wpa_pairwise=TKIP rsn_pairwise=CCMP Setup iptables: iptables -t nat -A POSTROUTING -s 192.168.76.0/24 ! -d 192.168.76.0/24 -j MASQUERADE Set wlan0_ap up: ip link set dev wlan0_ap up ifup wlan0_ap Restart dnsmasq: service dnsmasq restart Start hostapd: hostapd /etc/hostapd/hostapd.conf Configuration file: /etc/hostapd/hostapd.conf nl80211: Could not re-add multicast membership for vendor events: -2 (No such file or directory) Using interface wlan0_ap with hwaddr 02:00:00:00:00:00 and ssid "opi0plus2" wlan0_ap: interface state UNINITIALIZED->ENABLED wlan0_ap: AP-ENABLED hostapd seems happy, but there is no opi0plus2 ssid in a scan of the local wireless networks. I've tried the supplied interfaces.hostapd and /etc/hostapd.conf from Armbian, they don't work either. Any help? Oh, and Wijnen offered to work on the POS wireless drive, but radio silence from the Armbian crew. What's up with that?

Thanks for the reply, Igor. I would like to challenge your assertion since I presently have a Raspberry Pi Zero Wireless performing this function quite handily; for my purposes, anyway. The OPi0 is more useful given a quad core processor and more io, hence my interest in it. I'll take a look at the H3 version, however.

I've read many posts here and understand the OPi0 wireless chip isn't very well liked. I'm trying to setup hostapd with both client and AP functionality. I can get AP working only if I dedicate wlan0 to it. It seems that virtual devices (eg iw dev wlan0 interface add uap0 type managed; ip link set uap0 up) don't work with the current jessie image, making it impossible to have both AP and client simultaneously. I'm happy to help with testing the driver, but I'm no expert and certainly not knowledgeable enough to code this sort of stuff. If there's any help to be had, I'd be grateful.