Operating Systems of Mobile Devices (OSMZ)

Week XI. (19.4.-23.4.2021)

We are moving from current and actively developed OS to systems that are no longer developed today, and that is also systems from the extensive family of Windows CE products. Microsoft achieved its greatest expansion after the fall of PalmOS with its Windows CE 4.1 and 5.0 devices. However, Windows CE was just a kernel designation, the systems themselves were named according to the market / segment for which they were intended. In the presentation you will find on the timeline various commercial names such as Windows Handheld PC, Pocket PC, Smartphone, CE for Automotive, Windows Mobile. Compared to PalmOS (which we will describe later), this system offered a look and feel similar to desktop applications. Hardware requirements were greater from the very beginning, and users gained more options and new interfaces (WiFi, Bluetooth), which appeared at Palm with a considerable delay and a number of restrictions. Windows CE visually resembled Windows 95, but it was not a classic port of the system, as it might seem, but a completely new system with a different kernel. The only thing that connected it to desktops was the use of an almost identical Windows API, which made it easier for existing developers to switch to a mobile platform. Later, the .NET Framework extension appeared and the application could be written for the CLR and run independently of the platform (.NET Windows Mobile EXE file can also be run on a desktop PC).

Windows CE (and other embedded branches) is very modular (unlike desktops) and when building a system, you can choose whether it will be just a kernel without a graphical interface, or a fully graphical interface with IE and WMP. Windows Platform Builder was used for assembly - a tool that prepares the appropriate kernel image for a specific hardware platform. For a better idea of the system's features, you can download the Windows CE 5.0 emulator from the Microsoft website (currently only from the archive)

The core of the system uses virtual memory and MMU, but until version 5.0 a simplified variant with a mapping and division of the virtual address range into 32 slots of 32 MB, individual applications (of which there could be a maximum of 32) could allocate memory up to 32 MB limit. With Windows CE 6.0, this limitation has disappeared, and each process, which can now be up to 64,000, has its own virtual address range. Windows CE Scheduler supports real-time applications, has a number of more advanced features, and can solve problems arising from priorities (their inversion).

Microsoft embedded systems (not directly mobile segment) are commonly used at cash terminals (for example in T.S.Bohemia payment terminals), ATMs and other devices. However, manufacturers often use unsupported XP and Windows 7 systems and are thus a source of security risks (in hospitals, they are MRI and CT systems that can be attacked through known vulnerabilities, such as the SMB 1.0 protocol). A summary of embedded versions and their usage.

In 2016, Microsoft largely left the mobile business and fired most mobile developers. The development of Windows 10 Mobile was ended on January 14, 2020. Thus, only Windows 10 IoT Core remains available for embedded devices, but they do not contain a graphical interface or the standard Windows 10 for the ARM platform. Windows 10 can also be installed on the popular Raspberry Pi