Rpi 4 with Ubuntu Server tether network with usb-c

[eastinside]

I have a Raspberry Pi 4 4GB were I have installed Ubuntu Server 19.10, I'm trying to get network and power over a USB-C cable to an Ipad Pro. I follwed this tutorial https://www.hardill.me.uk/wordpress/201 ... -c-gadget/ to get it working with Raspian Buster and it worked. But I want to utilize the 64-bit support from Ubuntu.

I need help to figure out how to setup the network from the USB-C cable.

Any ideas are welcome

- I have check/update the bootloader
- I have added total_mem=3072 to /usercfg.txt so USB is working

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uname -a
Linux ubuntu 5.3.0-1007-raspi2 #8-Ubuntu SMP Thu Oct 10 12:42:47 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux

[phase]

i browsed over the articles..this is not my forte but you need to run an update the rpi4

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apt update && apt upgrade && apt dist-upgrade

this may be of some help your kernal is old

[depmod]

Hi @eastinside Did you figure out how to do it? I want to do the same.

[eastinside]

@depmod, no not yet! Still looking! I have also posted this questions here: https://askubuntu.com/questions/1193871 ... with-usb-c

[depmod]

@eastinside I will post here if I find out. Please post here as well if you find out through the other post.

[mbreese]

It looks like this is a bug in the Ubuntu RPi kernel. I *think* this patch should fix it, but I haven't tested it myself.

[https://bugs.launchpad.net/ubuntu/+sour ... ug/1861070]

(I've been trying to do the same thing)

[mbreese]

Using the testing PPA, I was able to successfully get this to work using this guide as a starting point: [https://www.hardill.me.uk/wordpress/201 ... -c-gadget/]

I'm tethering an Rpi 4 with Ubuntu server (arm64) to an IPad Pro.

This is really not all that recommended because it's a testing kernel, but if you enable the PPA from here: [https://launchpad.net/~canonical-kernel ... ubuntu/ppa], then you can get the fixed kernel module. If you can be patient for the kernel to finish going through the release process, then I'd recommend that.

But if you're as impatient as me, then this does work.

After you enable the PPA, you can upgrade the `linux-raspi2` package. This will install the fixed kernel module.

There are a few differences from the hardill guide that you'll want to keep in mind.

1) in your `/boot/firmware/usercfg.txt` file, you'll want to add `dtoverlay=dwc2,dr_mode=peripheral`. (I haven't tested it w/o the dr_mode=peripheral argument, so this might still work).

2) Ubuntu by default uses the systemd-resolved, so you'll have to also configure dnsmasq to disable its DNS server.

You can do this by adding the line `port 0` to the /etc/dnsmasq.d/usb file. This disables the DNS server, but keeps the DHCP server.

3) Instead of using the traditional `/etc/network/interfaces.d/usb0`, you can also use the default netplan setup for Ubuntu. Here is an example what what mine looks like (stored as /etc/netplan/99-custom.yaml):

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network:
  version: 2
  renderer: networkd
  wifis:
    wlan0:
      dhcp4: yes
      dhcp6: no
      access-points:
        "my-ssid":
          password: "secret-preshared-key"
  ethernets:
    eth0:
      dhcp4: true
    usb0:
      dhcp4: false
      optional: true
      addresses: [10.55.0.1/29]

4) In the /root/usb.sh script, I think you can remove the last two lines. (the `ifup usb0` and `system dnsmasq restart` lines).

That's what I currently have working. I'm not sure how stable it is yet, but so far, it does seem to be working. Again, this testing kernel PPA isn't recommended, but so far, so good.

Good luck!

[depmod]

Thanks a lot for the detailed explanation @mbreese. Great explanation. Which version of Ubuntu are you using? 18.04 or 19.10? Do you know how long does kernel take to finish going through the release process approximately? Do we need for the next release of Ubuntu? How do we know which stable release to use? Also do you think same instructions would work with other distros like Kali?

[mbreese]

I’m using 19.10 and this fix is slated to be in (I think) the next stable kernel. (It’s already been pushed out for testing, which is where the PPA version I’m using came from). Because it was effectively just going an ‘apt upgrade’, the process was pretty fast (15-20 min ish). If you had to actually compile the kernel, it would take a few hours I’m guessing. However, the first link does have the instructions for what to change in the kernel config — it’s a kernel config flag that needs to be set, not a code patch.

Not sure about anything other than Ubuntu... but if you have an error, this is a good place to start looking. There is a specific string in the dmesg log to look for. It is also shown in the first link above.

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Configuration mismatch. dr_mode forced to host

If you see this in dmesg, then this will be one of the issues.

[jcastroa87]

Hi im trying to follow this steps on Ubuntu Server 20.04, but i cant get this works, i dont know how to make /root/usb.sh execute on startup. Thanks in advance.

[mbreese]

Hi im trying to follow this steps on Ubuntu Server 20.04, but i cant get this works, i dont know how to make /root/usb.sh execute on startup. Thanks in advance.

From the hardill.me.uk link above (https://www.hardill.me.uk/wordpress/201 ... -c-gadget/):

Add /root/usb.sh to /etc/rc.local before exit 0 (I really should add a systemd startup script here at some point)

But, this is likely to be out of date with Ubuntu 20.04

[lsmith77]

Just to understand the steps above and try to apply them to Ubuntu Server 20.20. So far it is not yet working for me, but hoping with the summary, we can identify what needs to be adjusted.

Add dtoverlay=dwc2 to the /boot/config.txt
Add modules-load=dwc2 to the end of /boot/cmdline.txt

Replaced by 1) in your `/boot/firmware/usercfg.txt` file, you'll want to add `dtoverlay=dwc2,dr_mode=peripheral`. (I haven't tested it w/o the dr_mode=peripheral argument, so this might still work).

But does this really cover the modules-load bit?

If you have not already enabled ssh then create a empty file called ssh in /boot
Add libcomposite to /etc/modules
Install dnsmasq with sudo apt-get install dnsmasq

Remains the same

Create /etc/dnsmasq.d/usb with following content

Remains the same but add "port 0" at the end

Add denyinterfaces usb0 to /etc/dhcpcd.conf
Create /etc/network/interfaces.d/usb0 with the following content

Replaced by 3) Instead of using the traditional `/etc/network/interfaces.d/usb0`, you can also use the default netplan setup for Ubuntu. Here is an example what what mine looks like (stored as /etc/netplan/99-custom.yaml):

Create /root/usb.sh
Make /root/usb.sh executable with chmod +x /root/usb.sh

Remains the same, though potentially the last 2 lines can be disabled

Add /root/usb.sh to /etc/rc.local before exit 0 (I really should add a systemd startup script here at some point)

Remains the same once rc.local has been setup https://www.linuxbabe.com/linux-server/ ... th-systemd

*Update* Managed to fix the " For now it hangs for several minutes at "A start job is running .."." bit .. was due to not cleaning up the "/etc/netplan/99-custom.yaml" example. Also note one should run "sudo netplan generate; sudo netplan apply" after making changes to the netplan configs.

[jcastroa87]

i surrender with ubuntu, i cant translate steps, then i try with 64bits raspbian viewtopic.php?f=117&t=275370 i can do it, and it works with docker (the reason because i need a 64 bits OS)

[jcastroa87]

today i try this step by step on ubuntu 20.04, i get this on my macbook



i just get "169.254.249.92", i cant get fixed ip working, i want to get 10.55.0.1, but idk what i need to do.

Thanks i advance.

[Brestois]

Hi, did you get it working ?
I tried everything in this post, but not able to make it work.
Event though I’m getting an IP address in iPad’s Ethernet section, I cannot RDP inside. And my Ubuntu Mate 20 is not able to access to Internet using my iPad connection.

It’ll be great if someone comes up with a working example, because Ubuntu Mate is running perfectly on Raspberry Pi 4B without any lag.

[Rramnel]

If you can see an IP address from your iPad, why are you not able to connect to the raspberry Pi? It should work. Have you tried to ssh into it and install a VNC server?

[jreich]

I got it working on Ubuntu Server 64bit with the following setup:

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ubuntu@ubuntu:~$ uname -a
Linux ubuntu 5.8.0-1006-raspi #9-Ubuntu SMP PREEMPT Fri Oct 16 12:55:30 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux

installed today with the raspberry pi imager and selecting the Ubuntu 20.10 Server image

After writing the image to disk edit on the disk:
config.txt and add

dtoverlay=dwc2,dr_mode=peripheral

In cmdline.txt add

modules-load=dwc2,g_ether

after the rootwait with only one space in between as already discussed.

Adapt your network.config

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version: 2
    ethernets:
    eth0:
        # Rename the built-in ethernet device to "eth0"
        match:
        driver: bcmgenet smsc95xx lan78xx
        set-name: eth0
        dhcp4: true
        optional: true
    usb0:
        dhcp4: false
        optional: true
        addresses: [10.55.0.1/29]
    wifis:
    wlan0:
        dhcp4: true
    dhcp6: false
        optional: true
        access-points:
        "MyHomeNet":
            password: "MyPassword"
        "MyOtherHomeNet":
            password: "MyOtherPassword"

create '/etc/dnsmasq.d/usb

interface=usb0
dhcp-range=10.55.0.2,10.55.0.6,255.255.255.248,1h
dhcp-option=3
leasefile-ro
port=0

and uncomment the last line in /etc/default/dnsmasq

# If the resolvconf package is installed, dnsmasq will tell resolvconf
# to use dnsmasq under 127.0.0.1 as the system's default resolver.
# Uncommenting this line inhibits this behaviour.
DNSMASQ_EXCEPT="lo"

See here for an explanation: https://askubuntu.com/questions/818205/ ... ctionality

after reboot I have and you should also have:

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ubuntu@ubuntu:~$ ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.55.0.1  netmask 255.255.255.248  broadcast 10.55.0.7
        inet6 fe80::f084:4fff:fee9:3222  prefixlen 64  scopeid 0x20<link>
        ether f2:84:4f:e9:32:22  txqueuelen 1000  (Ethernet)
        RX packets 539  bytes 93361 (93.3 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 128  bytes 19380 (19.3 KB)
        TX errors 0  dropped 14 overruns 0  carrier 0  collisions 0

and also

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ubuntu@ubuntu:~$ systemctl status dnsmasq
? dnsmasq.service - dnsmasq - A lightweight DHCP and caching DNS server
     Loaded: loaded (/lib/systemd/system/dnsmasq.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2020-11-02 19:01:42 UTC; 26min ago
    Process: 1701 ExecStartPre=/etc/init.d/dnsmasq checkconfig (code=exited, status=0/SUCCESS)
    Process: 1752 ExecStart=/etc/init.d/dnsmasq systemd-exec (code=exited, status=0/SUCCESS)
    Process: 1765 ExecStartPost=/etc/init.d/dnsmasq systemd-start-resolvconf (code=exited, status=0/SUCCESS)
   Main PID: 1763 (dnsmasq)
      Tasks: 1 (limit: 9255)
     CGroup: /system.slice/dnsmasq.service
             +-1763 /usr/sbin/dnsmasq -x /run/dnsmasq/dnsmasq.pid -u dnsmasq -I lo -7 /etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new --local-service --trust-anchor=.,20326,8,2,e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d

Nov 02 19:20:14 ubuntu dnsmasq-dhcp[1763]: DHCPREQUEST(usb0) 10.55.0.6 ea:78:xx:xx:xx:3f
Nov 02 19:20:14 ubuntu dnsmasq-dhcp[1763]: DHCPACK(usb0) 10.55.0.6 ea:78:xx:xx:xx:3f MyIPad
Nov 02 19:26:12 ubuntu dnsmasq-dhcp[1763]: DHCPDISCOVER(usb0) ea:78:xx:xx:xx:3f

and also

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ubuntu@ubuntu:~$ modinfo g_ether
filename:       /lib/modules/5.8.0-1006-raspi/kernel/drivers/usb/gadget/legacy/g_ether.ko
license:        GPL
author:         David Brownell, Benedikt Spanger
description:    RNDIS/Ethernet Gadget
srcversion:     C7B1A05BBF09AA2ACF8D58C
depends:        libcomposite,u_ether,usb_f_rndis
intree:         Y
name:           g_ether
vermagic:       5.8.0-1006-raspi SMP preempt mod_unload aarch64
sig_id:         PKCS#7
signer:         Build time autogenerated kernel key
sig_key:        57:72:20:5E:A7:F3:46:4E:67:11:E4:1A:24:34:4B:40:ED:02:E3:C1
sig_hashalgo:   sha512
signature:      99:29:05:E2:71:81:90:0C:F2:60:5A:06:F9:7F:3E:D1:5B:AC:C5:2F:
                ...
                46:5B:EA:96:30:5A:70:C3:DC:26:E9:33
parm:           idVendor:USB Vendor ID (ushort)
parm:           idProduct:USB Product ID (ushort)
parm:           bcdDevice:USB Device version (BCD) (ushort)
parm:           iSerialNumber:SerialNumber string (charp)
parm:           iManufacturer:USB Manufacturer string (charp)
parm:           iProduct:USB Product string (charp)
parm:           qmult:queue length multiplier at high/super speed (uint)
parm:           dev_addr:Device Ethernet Address (charp)
parm:           host_addr:Host Ethernet Address (charp)
parm:           use_eem:use CDC EEM mode (bool)

On the iPad Pro (iPadOs 14.01) I do now see an Ethernet-Adapter "RNDIS/Ethernet Gadget" with IP 10.55.0.6 and subnetmask 255.255.255.248 and can indeed connect to the raspberry via ssh under 10.55.0.1

Note this is not the address under which the gadget is listed, but the one which we assigned statically and which ifconfig tells you for usb0.

Hope that still help somebody. So it appears as if one does not need the shell usb.sh script that modifies the parameters of g_ether for connecting to an Ipad. I have yet to establish connection with a windows pc and as of now, the raspberry pi is not even recognized when I plug it in. But maybe that is a topic for another thread.