pikvm/pages/building_os.md

Building the OS

The Pi-KVM OS is based on Arch Linux ARM and contains all the required packages and configs for it to work.

To build the OS you will need any Linux machine with a recent version of Docker (>= 1:19) with privileged mode enabled (used for fdisk and some other commands, have a look through our Makefiles if you don't trust us :)).

The build must be performed on the target x86_64 Linux image.

Ubuntu 20.04 is recommended and has been tested. please note that Ubuntu 18.04 does not work.

0. When starting with a clean OS you need to install and configure docker (after adding your user to the docker group you must log out and log back in), as well as git and make.

   [user@localhost ~]$ sudo apt-get install git make curl binutils -y
   [user@localhost ~]$ curl -fsSL https://get.docker.com -o get-docker.sh
   [user@localhost ~]$ sudo sh get-docker.sh
   [user@localhost ~]$ sudo usermod -aG docker $USER
   

   Re-login to apply the changes.

1. Git checkout the build toolchain:

   [user@localhost ~]$ git clone https://github.com/pikvm/os
   [user@localhost ~]$ cd os
   

2. Determine the target hardware configuration (platform):

• Choose the board: BOARD=rpi4 for Raspberry Pi 4 or BOARD=zerow, BOARD=rpi2, BOARD=rpi3 for other options.
• Choose the platform:
  • PLATFORM=v2-hdmi for RPi4 or ZeroW with HDMI-CSI bridge.
  • PLATFORM=v0-hdmi for RPi 2 or 3 with HDMI-CSI bridge and Arduino HID.
  • PLATFORM=v2-hdmiusb for RPi4 with HDMI-USB dongle.
  • PLATFORM=v0-hdmiusb for RPi 2 or 3 with HDMI-USB dongle and Arduino HID.
  • Other options are for legacy or specialized Pi-KVM boards (WIP).

3. Create the config file config.mk for the target system. You must specify the path to the SD card on your local computer (this will be used to format and install the system) and the version of your Raspberry Pi and platform. You can change other parameters as you wish. Please note: if your password contains the # character, you must escape it using a backslash like ROOT_PASSWD = pass\#word.

   [user@localhost os]$ cat config.mk
   # rpi3 for Raspberry Pi 3; rpi2 for the version 2, zerow for ZeroW
   BOARD = rpi4
   
   # Hardware configuration
   PLATFORM = v2-hdmi
   
   # Target hostname
   HOSTNAME = pikvm
   
   # ru_RU, etc. UTF-8 only
   LOCALE = en_US
   
   # See /usr/share/zoneinfo
   TIMEZONE = Europe/Moscow
   
   # For SSH root user
   ROOT_PASSWD = root
   
   # Web UI credentials: user=admin, password=<this>
   WEBUI_ADMIN_PASSWD = admin
   
   # IPMI credentials: user=admin, password=<this>
   IPMI_ADMIN_PASSWD = admin
   
   # SD card device
   CARD = /dev/mmcblk0
   

   If you want to configure wifi (for ZeroW board for example) you must add these lines to config.mk:

   WIFI_ESSID = "my-network"
   WIFI_PASSWD = "P@$$word"
   

4. Build the OS. It may take about one hour depending on your Internet connection:

   [user@localhost os]$ make os
   

5a. Put SD card into card reader and install OS (you should disable automounting beforehand: systemctl stop udisk2 or something like that): shell [user@localhost os]$ make install

5b. Make the image to copy elsewhere and burn on to SD shell [user@localhost os]$ make image Image is then available as a bziped file in images/

6. After installation remove the SD card and insert it into your RPi. Turn on the power. The RPi will try to get an IP address using DHCP on your LAN. It will then be available via SSH.

7. If you can't find the device's address, try using the following command:

   [user@localhost os]$ make scan
   

8. Only for v0: Flash the Arduino HID.

9. Congratulations! Your Pi-KVM will be available via SSH (ssh root@<addr> with password root by default) and HTTPS (try to open in a browser the URL https://<addr>, the login admin and password admin by default). For HTTPS a self-signed certificate is used by default.

   The latest versions of Chrome do not allow access to the page with a self signed certificate. You can proceed by typing thisisunsafe and Chrome will then load the page

10. To change the root password use command passwd via SSH or webterm. To change Pi-KVM web password use kvmd-htpasswd set admin. As indicated on the login screen use rw to make the root filesystem writable, before issuing these commands. After making changes, make sure to run the command ro.

11. Important note for HDMI-USB dongle users only. Because of this, many video capture devices tell the server's video card that the HDMI cable is supposedly disconnected. This may lead to the fact that if you boot the server without an active stream, the server will not detect your capture card. This is easy to fix:

    • Switch filesystem to RW-mode:

      # rw
      

    • Edit file /etc/kvmd/override.yaml and add these lines:

      kvmd:
          streamer:
              forever: true
              cmd_append: [--slowdown]
      

    • Finish:

      # ro
      # systemctl restart kvmd
      

12. 27.08.2020 note about systemd: the latest version of Arch Linux has a slightly broken systemd. The problem is that SSH to the Pi-KVM host may not work the first time, but the second or third. The Pi-KVM build environment contains a workaround for this problem: in the file /etc/pam.d/system-login line -session optional pam_systemd.so is commented. This does not have any negative impact on the PI-KVM functionality, but if you want to, after fixing the systemd (in a couple of months with the next update), you can uncomment this line.

Further Help

If you have any problems or questions, contact us using Discord: https://discord.gg/bpmXfz5

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