zagtOS - a microkernel operating system written in C++

Current features include:

• SMP
• RTTI, Exceptions, STL-like scoped locks, smart pointers, vectors, and minimal undefined behavoir sanitizer in the kernel
• full runtime support in user space using the musl C library and GNU libstdc++
• GCC cross compiler for the *-zagtos target for user space code
• ZBON, a binary data serialization format, used for message passing and for program binaries, which are converted from ELF
• Memory Management and Futexes with a Linux-like syscall interface
• Message passing IPC which is also used for passing handles for access restricted things, like a region of physical address space, or an IPC Port of another user-space Process
• Interrupt handling by user space Processes (still missing a lot of cases)
• Bootloader/Kernel handover protocol designed with Live Kernel upgrades in mind (currently the bootloader loads a first Process, which contains the following processes, instead of an initrd-like mechanism)
• Bootloader for both UEFI and Multiboot2
• An own build tool to track dependencies between subprojects
• DebugBridge that can collect core dumps of Processes over the (virtual) serial port
• Currently on x86_64 and ARMv8 (WIP)
• Current area of work: adding storage / file system support

Building

Requirements:

• everything required to build gcc
• GNU parted, GRUB to create the disk image

Installing requirements on Windows (MSYS2)

pacman -S make gcc nasm texinfo diffutils bison flex mpc-devel lz4

(you also need grub and android-tools to generate boot images, there are no instructions for these yet)

Installing requirements on Arch Linux

sudo pacman -S base-devel nasm libmpc grub android-tools

Build

If all of these are installed, you should be able to build with just:

make

(This has not been tested on many systems yet, please let me know in which way it goes wrong)

Once the build is complete, a BIOS and UEFI bootable disk image is created at out/x86_64/disk.img. Scripts for running the system in different emulaters are in the emulate directory, intended to be used from the project root like:

./emulate/x86_64/qemu.sh

VritualBox

(currently not working due to hard dependency on TSC deadline mode which is not available in VirtualBox)

For VirtualBox, additional setup of the VM is required. The Paravirtualization type needs to be set to minimal, and for the DebugBridge to work, the serial port COM1 needs to be bound to TCP port 30000. The script currently assumes the VM is called Test. On launch it coverts the disk.img to disk.vdi which can be added to the VM.

Third Party Software

• src/ACPIHAL/acpica The ACPICA ACPI library. Used for user-space ACPI support (GPLv2)
• src/kernel/memory/dlmalloc.c dlmalloc Allocator used in the Kernel (Public Domain)
• src/binutils GNU Binutils
• src/gcc GNU GCC, incldung libgcc, libsupc++, libstdc++
• src/gmp, src/mpc, src/mpfr GCC dependencies, not yet used
• src/musl musl C library (MIT/BSD)
• src/gnu-efi GNU EFI, used by zagtOS loader (BSD)
• src/mtools GNU Mtools used to generate FAT file system for x86_64 boot image (GPLv3)
• src/parted GNU Parted used to generate x86_64 boot image (GPLv3)

Licensing

ZagtOS is released under the GNU General Public License (GPLv3)