Mercury

Mercury is a WIP x86-32 kernel.
Report problems or give suggestions here (Issue page)
Tested & working on REAL hardware

Building and booting

To build the kernel and create a bootable image including grub: sudo make grub

To run the kernel using qemu: make qemu Or using bochs: make bochs

Features

• FAT16 driver
• ELF32 App / SO loader
• Multitasking

Kernel Development Roadmap

Process Isolation

• Per-process page directories & address space separation
• User vs. kernel memory protection via page flags
• User stack and heap management (brk()-like syscall)
• Switch cr3 on context switch to isolate memory

Linux-like Syscalls

• Syscall mechanism (e.g. int 0x80, syscall/sysret)
• Syscall table and dispatcher
• Basic syscalls: read, write, open, close, exit, execve
• User-space test program using syscalls

C Standard Library

• Syscall wrappers (write(), read(), etc.)
• String/memory functions (memcpy, strlen, etc.)
• File I/O (fopen, fread, fclose)
• Static linking support (libc.a)

FAT32 Filesystem

• Block device abstraction
• BPB and FAT table parsing
• File access (open, read, close)

Driver Loading from Files

• Define driver format (e.g. ELF + metadata)
• Extend ELF loader for driver files
• Kernel driver registration API
• Load driver from FAT32 and call init()

Init or Shell

• Launch shell or init from FAT32
• Load userland apps using execve

On the way..

• Finish SATA driver
• Start with networking
• Maybe switch to GRUB

Screenshots
Multitasking and SO loading working:
You can see two idle tasks counting up and a program using functions from LIBC.SO running