Creation of an Operation System image (system software doesn't matter) for Raspberry Pi that contains minimum functionality (WLAN & Sound)

Creation of an Operation System image (system software doesn’t matter) for Raspberry Pi that contains minimum functionality. - The system will start automatically when connected to electrical power - No errors must occur when closing the software or removal from electrical power supply. The device must function properly afterwards. - Automatic embedding of a USB WLAN adapter - Audio output via phone jack (basic signal tone) - Video output is not necessary, because Raspberry will be operated without monitor When the Raspberry is connected to electrical power it will start automatically. It will scan permanently and without any interruption for available SSIDs in the service area. The scan will occur via the connected WLAN adapter. Scanning permanently for WLAN is the only task of the adapter. After starting the Raspberry it will run a self-test and confirm the readiness for use with an audio signal. The self-test shall test whether the WLAN adapter is properly connected and whether the software is ready for use. The readiness includes the permanent scan for SSIDs. Whenever a proper SSID (combination) is found the acoustic warning will occur.