Luminary is a small x86 real-time operating system written in C and assembly. Its goal is to implement a kernel that includes a hard real-time scheduler that can run time-sensitive tasks.

It takes concepts from an existing operating system by the same author called Ulysses.

Written by Sam Kingston.

Latest version: 0.10.0

• Small codebase
• Hard priority-based preemptive scheduler
• Flat memory model (no virtual addresses)
• Support for basic I/O drivers

Some architecture notes and gotchas are located in NOTES.md.

You may configure the build by editing the $DEFINES variable at the top of src/Makefile.

Available options are:

• -DDEBUG: produce debugging output to the console. You probably want this with -DTURTLE
• -DTURTLE: scale the scheduler down to 1 task per second
• -DUSE_SERIAL: enable the serial subsystem, which writes console output to COM1. This may be used with qemu -nographic.

First, ensure all build requirements are met:

• gcc and GNU as compilers that are capable of producing 32-bit executables
• glibc-devel.i686

Then, building the kernel is as simple as running the included Makefile:

$ make -C src

After building, you may run the kernel in QEMU with some shortcuts:

To have QEMU load the kernel image directly, opening an SDL window (fastest):

$ make -C src qemu

Or to build a bootable ISO image with Grub2 Multiboot and boot that way (requires xorriso):

$ make -C src qemucd

You may also redirect output to the terminal by using:

$ make -C src console

Note that the kernel must be built with the -DUSE_SERIAL option for this to work or you will get no output from the kernel.