SUNIX by IPlayZed

This is a hobbyist project focused on creating a UNIX-like kernel. The main goal of the project is to be multiboot compliant and bootable through a bootloader supporting the multiboot standard. The architecture in mind now is x86_64 and it is assumed that the system is in legacy BIOS mode.

Build and install

Environment

• Ubuntu 20.04
• Install dependencies: sudo apt install g++ binutils libc6-dev-i386 make
• Optional dependencies (if you plan to boot the kernel with Qemu): sudo apt qemu-system-x86

Boot with Qemu

Most will prefer this.

Boot from image

1. Issue make run in src.

Kernel-only mode

1. To build and install issue command make install in src.
2. To boot the kernel with Qemu issue qemu-system-i386 --kernel mykernel.bin in out.

Boot on real hardware with GRUB2

Create bootable image

Issue make sunix.iso in src. You can write this to an external media with any known methods, like dd or Balena Etcher. The image is self bootable, as it contains GRUB2, with an entry to the kernel.

Install the kernel to an already existing system

This will NOT break your system in any way ;). If you want to run it on bare metal, you must have GRUB2 installed on the host system.

The kernel binary by default is installed into /boot with make grubinstall. There are multiple ways to add it as an entry, but the easy and dirty way is to add it explicitly as a custom binary into the generated GRUB script, which is located at /boot/grub/grub.cfg.

For instance you could add the following at the END OF THE FILE:

### BEGIN MYKERNEL ###

menuentry 'SUNIX'{
    multiboot /boot/mykernel.bin
    boot
}

### END MYKERNEL ###

Main goals

This list is not final and may be modified freely throughout the evolution of the project.

• Take control over from GRUB2.
• Booot into a loop.
• Write out some text.
• Implement the Global Descriptor Table (GDT).
• Write out decimals.
• Write out hexadecimals.
• Output to a serial port.
• Interrupt handling system.
• Exception handling system.
• Dump the contents of the register.
• Dump the adress in case of a fault.
• Plan a physical memory map.
• Plan a virtual memory map.
• Implement "malloc".
• Implement "free".
• Give control over to init.