Details for How to develop an OAL .Step-by-step to develop an OAL. An OEM adaptation layer (OAL) is a layer of code between the Windows CE kernel and the hardware of your target device. You develop an OAL to communicate data between your operating system (OS) and your target device and include code to handle interrupts, timers, and so on.-Details for How to develop an OAL. Step-by - step to develop an OAL. An OEM adaptation layer ( OAL) is a layer of code between the Windows CE ker nel and the hardware of your target device. You d evelop an OAL to communicate data between your o perating system (OS) and your target device and include code to handle interrupts, timers, and so on.