Create faq.md

Translation of current FAQ

en/faq.md

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+# OpenIPC Wiki
+[Table of Content](../index.md)
+
+Questions and answers
+----------------
+
+### How to configure ssh session authorization by key
+
+__On the camera__: Open an ssh session and create a non-empty password for the root user. By default, in our firmware
+the root user does not have a password. Keep in a mind that after you have created a password, all subsequent new ssh sessions 
+will require authorization with this password until the moment you set up the public key authorization,
+as well as when trying to log in from a computer which does not povides such key. Don't forget it!
+```
+passwd
+```
+
+__On the desktop__: Copy the public key to the camera by logging in with the password created above.
+```
+ssh-copy-id root@192.168.1.666
+```
+
+__On the camera__: Create a `.ssh` folder in the root user's home directory and copy the file with the authorized keystore into it.
+```
+mkdir ~/.ssh
+cp /etc/dropbear/authorized_keys ~/.ssh/
+```
+
+__On the desktop__: Open a new session to verify that the authorization is passed using the public key not requesting a password.
+```
+ssh root@192.168.1.666
+```
+
+### Majestic
+
+#### How to get a memory dump for debugging?
+Enable and configure Core Dump in the menu Majestic > Majestic Debugging.
+
+#### Camera image has a pink tint
+You need to specify the GPIO pins to control the infrared filter.
+The settings for some cameras can be found in the [table](https://openipc.org/wiki/en/gpio-settings.html).
+If your camera is not in the table, then you will need the [ipctool](https://github.com/OpenIPC/ipctool/releases/download/latest/ipctool) utility.
+
+The OpenIPC firmware will automatically download the latest version of the utility to the /tmp directory when `ipctool` is invoked first time.
+On native firmware, you will need to download the utility to the camera yourself using the tools available in the system: wget, curl, tftp...
+For example, download the ipctool utility to TFTP server on the local network, then download it to the camera:
+```
+tftp -g -r ipctool -l /tmp/ipctool 192.168.1.1
+chmod +x /tmp/ipctool
+/tmp/ipctool
+
+```
+If the camera has internet access, you can try to mount a public NFS sharing and run the utility from it, without downloading to the camera:
+```
+mkdir -p /tmp/utils
+mount -o nolock 95.217.179.189:/srv/ro /tmp/utils/
+/tmp/utils/ipctool
+```
+
+After the utility is downloaded to the camera, run the `ipctool gpio scan` command in the terminal and open-close the camera lens a couple of times with your palm.
+Watch the output of ipctool to determine the pins responsible for controlling the IR filter curtain.
+Enter the values obtained in the settings for the night mode Majestic. If the pink tint still persists, you may need to enable sensor signal inversion.
+
+Don't forget to add the camera model and found GPIO values to the table!
+
+#### Is it possible to display the data for setting the auto focus of lenses instead of the current sample_af in the standard /metrics?
+No, this is a difficult algorithm, it does not have a sense to run it this way.
+
+#### Copy files from Linux system to camera
+Sometimes you need to transfer files to the camera. In addition to the above method using NFS (Network File System)
+you can use the standard Linux scp command to copy files over an SSH connection:
+```
+scp ~/myfile root@192.168.1.65:/tmp/
+```
+This command will copy myfile from the home directory to the /tmp directory on the camera.
+On recent Linux systems the following error may occur:
+```
+sh: /usr/libexec/sftp-server: not found
+scp: Connection closed
+```
+
+Add -O option in this case:
+```
+scp -O ~/myfile root@192.168.1.65:/tmp/
+```