Operating Systems Development

manpreet Best Answer 2 years ago

My proposal for creating a hobby OS Dev SE was closed as a duplicate of computer science SE.

While I certainly don't agree with that, what should I expect to happen for proposing the same site but with a broader scope, say Operating System Development. This does not include writing modules for Linux or anything specific to a particular OS. This site considers questions related to general operating system development.

Why do I believe that OS Dev does not fit into Computer Science SE?

Here is a question related to operating system development but is bound to get closed in CS SE as off-topic.

1. How do I distinguish between onboard and PnP PCI devices?

2. How can I use unreal mode to load a kernel past 1MB using BIOS interrupts?

3. Setting GDT register causes CPU to triple fault

4. Do I have to wait for the i8259 for a response before sending out an ICW?

5. What are the methods used to keep the kernel code independent of the system architecture?

6. Is loading a hardware abstraction layer as a separate module which in turn loads the kernel expensive?

7. Why are 12bit entries used instead of 16bit entries in FAT12 file system?

8. Efficiency of moving FPU state from one core to another

Operating system development is a specialization and hence, most programmers or computer scientists who haven't specialized in the field would have little to zero clue about OS development. A person who is trying to optimizing algorithms or working on a new faster algorithm to factor numbers won't be able to answer questions on operating systems.

Operating system development is a very broad field and doesn't fit well in any of the existing Q&A sites.

Topics which might be covered in operating system development could be:

1. General Topics

   1. Processor Architecture
      • x86 (serves as an example, this site would support more architectures)
        1. Global Descriptor Table
        2. Interrupt Descriptor Table
        3. CPU Exceptions
        4. Real Mode
        5. Virtual 8086 Mode
        6. Protected Mode
        7. Long Mode
        8. Unreal Mode
      • ARM
      • MIPS
      • PowerPC
   2. Memory Architecture
   3. Operating System Design
   4. Hardware Abstraction

2. Build toolchain and emulators

   1. Building crosscompilers
   2. Standard Libraries/Freestanding
   3. Assembler Selection
   4. Emulators

3. Firmware

   1. Basic Input Output System
   2. SM BIOS
   3. UEFI
   4. BIOS Data Area (BDA/EBDA)
   5. Boot process

4. Kernel Design

   1. Monolithic Kernel
   2. Micro Kernel
   3. Nano Kernel
   4. Hybrid Kernel
   5. Exo Kernel
   6. Modular Kernel
   7. Kernels for virtualization

5. Process Management/Multitasking

   1. Interprocess Communication
   2. Scheduling
   3. Task Models (monotasking, multitasking, real-time)
   4. Multiprocessor Task Switching
   5. Semaphores
   6. Spinlocks
   7. System Calls
   8. Priority Tree
   9. Threads

6. Memory Mangement

   1. Physical Memory Management
   2. Virtual Memory Management
   3. Segmentation
   4. Memory Models
   5. Paging
   6. Memory Allocation/Deallocation
   7. Heap, Garbage Collectors, etc.

7. Devices and Drivers

   1. Timers and Clocks
   2. Peripheral Component Interconnect (PCI)
   3. Peripheral Component Interconnect Express (PCIe)
   4. Universal Serial Bus (USB)
   5. Network Devices
   6. Storage Media
      • Floppy Disks
      • ATA
      • ATAPI
      • DMA
      • AHCI
   7. Keyboard, Mouse
   8. Serial Ports
   9. Parallel Ports
   10. Video
   11. Audio

8. Input/Output

   1. Deadlocks
   2. Interrupts Requests
   3. Interrupt Service Routines
   4. Sharing Interrupts
   5. Programmable Interrupt Controller (PIC)

9. File Systems

   1. Files and Directories
   2. Implementation
   3. Security
   4. Existing file systems
      • ext
      • FAT12/16/32
      • NTFS
      • VFS
      • and more

10. User-interface

    1. Graphical User Interface
    2. Window Managers
    3. Command Line Interface/Shell/Terminal

There are topics which at first might seem to belong to an existing SE site. For example, interrupts are used in DOS but this has almost nothing to do with what we are talking here. The DOS interrupts are ways to trigger interrupts and install interrupt handlers. When we talk about interrupts in the scope of the proposed site, we are talking about programming the interrupt controllers, setting up interrupt vector tables, etc.

When we talk about memory allocation, we are not talking about the new or delete operators. In fact, the C++ new and delete operators are simply not available in operating system development. An OS developer will have to implement his own methods to allocate and deallocate memory. In our context, memory allocation would mean about managing and finding free memory blocks and allocating them to the process which requested it.

A more silly example might be timers. The standard library provides a time library but this has nothing to do with operating system development. In fact, the time library provided by the standard library is pretty much useless. When we talk about timers in the operating system development context, we talk about programming the PIT or HPET device and using their facilities to maintain a tick count.

For obvious reasons, this is not computer science and hence OS Dev SE is not a duplicate of computer science.

manpreet 2 years ago