NT-Lite -- an x86-64 kernel
Boots. Runs processes. Mimics Windows to some extent.
what is it?
A 64-bit operating system kernel written from scratch.
UEFI bootloader, physical and virtual memory managers, preemptive scheduler, HAL, VFS, PE loader, partial Win32 layer.
It boots into a shell.
~20k lines of C and assembly.
features
- UEFI bootloader
- physical memory manager
- virtual memory manager with kernel pool
- HAL (screen, keyboard, timer, disk, PCI, APIC)
- preemptive scheduler with priority levels
- processes and threads
- VFS
- drive-letter paths (
0:\apps\shell.exe) - INI-based boot and driver configuration
- partial Win32 layer (kernel32 and user32, far from finished but capable of running simple apps)
- PE import resolution and dynamic driver loading
how 2 build
- open vs x64 build tools
- cd into this directory
build.bat- open
run.bat/rund.bat - replace
\\.\PhysicalDrive7with your thumbdrive partition run.bat/rund.bat- enjoy
driver model
drivers are PE32+ .sys files with an entry point preferably named DriverEntry accepting a constant pointer to HAL_API.
drivers to be loaded have their path stored in drivers.ini, split into essential for boot (loaded by bootloader) and not required for boot (loaded by kernel).
a disk driver fills in a DISK_DRIVER vtable and calls IoRegisterDisk(index, &driver).
a filesystem driver fills in an IO_FILESYSTEM vtable and calls IoRegisterFilesystem(index, &fs, &vol).
how it boots
- UEFI loads
boot.ini, readsdrivers.ini - bootloader maps kernel, HAL, and boot drivers into the upper half
- direct physical window at
0xFFFF880000000000 - jumps to
KernelMain - PMM, VMM, GDT, IDT, HAL, IRQs, scheduler
- loads runtime drivers from disk
- launches
shell.exe
paths
"apps\shell.exe" -> drive 0
"0:\apps\shell.exe" -> drive 0
"2:\data\config.ini" -> drive 2
drives 0–7. a drive only works if a filesystem registered on it.
screenshots
faq
Q: Why?
A: Why not?
Q: Does it run Doom?
A: Not yet.
Q: Is the Win32 layer real?
A: Real enough to load binaries that expect it. Not real enough to run Notepad.
Q: Is the scheduler preemptive?
A: As much as it will ever be.
Q: Will it corrupt my data?
A: How would it? It's read-only.
Q: Is this finished?
A: Not in the slightest.
Q: Can I use this in production?
A: Don't.