Merge branch 'master' of github.com:tiyn/wiki

wiki/linux/disk-management.md

@@ -23,7 +23,6 @@ Then the swap file can be changed using the following commands.
 `<location>` is the location of the swap file (for example `/swap.img`).
 `<size>` describes the new size of the swap file (for example `16G`)
 
-
 ```sh
 swapoff <location>
 fallocate -l <size> <location>
@@ -176,12 +175,25 @@ The following list shows some options to quickly clean up space.
 - [Package Mangers](/wiki/linux/package_manager.md)
 - [ViFM Trash Bin](/wiki/linux/vifm.md#empty-trash)
 
+## Accessing Disks as User
+
+Sometimes - for example when flashing an SD card for a
+[Raspberry Pi](/wiki/linux/raspberry_pi.md#setup) - it may be useful to do so with your default
+user and not using the root user.
+For this to work the user can be added to the `disk` group permanently.
+Please note that this however reduces the systems security.
+A command to do so, may look like the following (given the `$USER` variable is set correctly).
+
+```sh 
+usermod -a -G disk $USER
+```
+
 ## Error solving
 
 This section addresses various problems that can occur and are related to
 disk-management.
 
-### sudo: unable to open ... Read-only file system
+### `sudo: unable to open ... Read-only file system`
 
 Ususally the filesystem will go into read-only mode whe the system is running
 and there is a consistency error.
@@ -193,7 +205,7 @@ To fix it run:
   you may want to try using the ext4-specific fsck:
 - `fsck.ext4 -f /dev/sda1`
 
-###  cannot access: Transport endpoint is not connected
+### `cannot access: Transport endpoint is not connected`
 
 This error message can occur if a mounted directory is left mounted due to a
 crash of the filesystem but not accessible anymore.

wiki/linux/raspberry_pi.md

@@ -2,6 +2,29 @@
 
 A [Rapberry Pi](https://www.raspberrypi.com) is a single board comuter.
 
+## Setup
+
+For setting up a classic Raspberry Pi an SD card is needed that contains the operating system.
+
+For this an image has to be flashed.
+The images of the operating systems can be found on the
+[official website](https://www.raspberrypi.com/software/operating-systems).
+A command to flash may look similar to the following example, where `<img-path>` is the path to the
+image and `<disk-path>` is the path to the device to flash to (for example `/dev/sdb1`).
+
+```sh 
+dd if=<img-path> of=<disk-path> status=progress
+```
+
+This however can also be done using the Raspberry Pi imager - which most
+[package managers](/wiki/linux/package_manager.md) package under `rpi-mager`.
+It too can also be found on the [official website](https://www.raspberrypi.com/software).
+When using the imager as a non-root user this user may have to be given rights to access disks or
+at least the SD card as described in the
+[corresponding article](/wiki/linux/disk-management.md#accessing-disks-as-user).
+
+The setup using the imager is guided and easier.
+
 ## Hardware Additions
 
 There are various hardware additions which can be used with the Raspberry Pi.
@@ -56,3 +79,16 @@ hailo parser tf <path-to-tf-model>
 hailo optimize --use-random-calib-set <path-to-har-model>
 hailo compiler <path-to-optimized-har-model>
 ```
+
+Note that the user in the Docker container usually uses anothr UID and GID.
+To make the volume and files accessible inside the container the IDs of the files in the volume
+should be changed accordingly - for example as shown in the following example.
+`<volume-path>` is the path that points to the volume
+`<uid>` is the UID of the Docker user - which can be found using `id -u` (for example `10642`) -
+and `<gid>` the GID of the Docker user - which can be found using `id -g` (for example `10600`).
+
+```sh 
+chown -R <uid>:<gid> <volume-path>
+```
+
+After the models have been converted it can be reversed using the systems user UID and GID.