Bnyeh Kernel

I'm completely insane now, I am writing my own kernel to learn how low-level hardware programming works.

Goal

The goal of the kernel (for the moment) is to get a user-space setup with a small N64 emulator and having enough APIs to run and play the games. This is both to teach me how to write a use for a kernel as well as writing an emulator.

Why?

I need/want to learn low-level hardware development so I can possibly contribute to the linux kernel. I also want to try and use C/assembly in a kernel space with full control over the hardware and how it operates.

AND BECAUSE I AM INSANE OF COURSE!

Current State

This is just a small list of all the working and non-working things. See the TODO.txt file for what needs to be done (and will likely not be working).

Working or completed

• Basic VGA Display - Completed

• Full VGA color terminal with printf-like functions

• Color logo prints to screen

• Printing string/characters different colors works

• Memory - Completed

• Paging works

• Basic heap allocations

• kalloc and kfree are available

• Everything is ready for Multi-tasking and scheduling of user space processes.

• Need to get length of memory, not sure how to go about this yet currently it allocates until a CPU exception happens.

• Disk - WIP

• Some code for PATA has been written

• kernel otherwise has no clue what a hard drive is

• FAT32 support with MBR/GPT planned.

• Keyboard - WIP

• Left and Right shift keys work

• caps lock key works

• caps lock + shift behavior works

• Upper and lower case prints to terminal

• Only prints to terminal, causes no other actions (yet)

• Time - Completed

• Gets the current CMOS time

• Continues counting seconds from Unix EPOCH

• localtime_r() and similar functions calculate off my timezone (UTC+7) so timezones are incomplete.

• Multi-tasking and Userland! - WIP

• Memory management in place for user processes

• Some syscall stuff has been made

• Fully working C environment

Todo

• Getting length of memory installed in the system
• Booting in a bootloader other than grub2
• netbooting
• real hardware testing
• other architectures (such as amd64 and arm)
• driver api

Compiling

CMake will automatically try and use Clang over GCC because Clang is easier to debug with and produces binaries faster than GCC (plus it's my favorite compiler).

If you don't have clang then CMake should default to the system compiler but if it doesn't then please file a bug.

To compile with gcc:

1. run tools/mkcrosscompiler_gcc.sh
2. mkdir build
3. cd build
4. cmake -DUSE_GCC_TOOLCHAIN:BOOLEAN=TRUE ..
5. make
6. make iso

This will build the kernel and make an iso file located as Kernel.bin and Kernel.iso in the root of the build directory.

Note: You can change the build directory to be anywhere on the computer, see CMake's website for that.

To compile with clang:

Install clang from your distro's package manager

1. mkdir build
2. cd build
3. cmake ..
4. make
5. make iso

This will build the kernel with clang. CMake will automatically pick the right settings for cross-compilation to i386 processors.