Freax

since Linux was originally going to be named Freax, I may as well do it myself.

WE USE NASM SYNTAX FOR ASSEMBLY CODE. WRITTEN IN C++. CURRENTLY DONE WITH A BASIC MULTIBOOT BOOTLOADER. BASIC GDT IMPLEMENTED.

https://pubs.opengroup.org/onlinepubs/9799919799.2024edition/

For a POSIX-compliant Unix-like OS, here's a suggested roadmap of key components to implement, roughly in order of priority:

1. Memory Management

   • Physical Memory Manager
   • Virtual Memory Manager (Paging)
   • Kernel Heap (kmalloc/kfree)
   • User Space Memory Management

2. CPU Management & Protection

   • GDT (Global Descriptor Table)
   • IDT (Interrupt Descriptor Table)
   • Basic exception handling
   • IRQ handling
   • User/Kernel mode separation

3. Process Management

   • Process structures
   • Task switching
   • Scheduler
   • Fork/Exec implementation
   • Signal handling (crucial for POSIX)

4. File System

   • VFS (Virtual File System) layer
   • Initial RAM disk
   • Basic file operations (open, read, write, close)
   • Implementation of a simple filesystem (ext2 is good to start with)
   • Device file system (/dev)

5. System Calls

   • Syscall interface
   • Basic POSIX syscalls
   • File operations
   • Process operations
   • Memory operations

6. Device Drivers

   • PIC (Programmable Interrupt Controller)
   • PIT (Programmable Interval Timer)
   • Keyboard driver
   • Storage drivers (IDE/SATA)
   • Basic networking stack

7. IPC (Inter-Process Communication)

   • Pipes
   • Signals
   • Shared memory
   • Message queues
   • Semaphores

8. User Space

   • C library implementation (or minimal libc)
   • Basic shell
   • Init system
   • Basic utilities (ls, cat, etc.)

For the immediate next step, I'd suggest starting with memory management since it's fundamental to everything else. Want me to help you set up a basic physical memory manager?

Some specific POSIX requirements to keep in mind:

• File system hierarchy standard (/bin, /etc, /dev, etc.)
• Standard I/O streams (stdin, stdout, stderr)
• Process groups and sessions
• File permissions and ownership
• Standard signal handling
• TTY/PTY support

This is a big project, but starting with memory management will give you a solid foundation to build upon.