MinOS

The third rewrite of MinOS

Ports

• Musl 1.2.3
• Lua 5.4.4
• Doom :-)
• Scalable Screen Font 2.0

Toolchain and userspace

MinOS uses Musl as its standard library, and uses Clang to build it. For userspace, a GCC cross-compiler is used (i686-minos-gcc).

Dependencies

On Fedora:

• clang
• gcc
• g++
• lld
• nasm
• binutils
• cmake
• xorriso
• grub2-pc
• grub2-tools-extra
• clang-tools-extra
• texinfo
• wget
• patch

Building

The full toolchain can be built like so:

./scripts/build_musl.sh &&\
./scripts/build_toolchain.sh

Then build the project:

# (after adding toolchain/prefix/bin to path)
mkdir build
cd build
cmake -DCMAKE_TOOLCHAIN_FILE=../toolchain/CMake/toolchain.cmake .. -G Ninja
ninja

Musl changes

• src/thread/i386/__set_thread_area.s has been commented out, and a stub provided in __init_tls.c instead (which avoids manipulating segment registers)
• arch/i386/pthred_arch.h has been stubbed out (for the same reason as above)
• crt/crt1.c supports the change above with a false pthread (and is patched to fix a clang build error with memset being undeclared)
• this all means that TLS is not supported yet

Running with Qemu

qemu-system-i386 -cdrom build/MinOS.iso -serial mon:stdio

Attributions

• Uses the Perfect DOS VGA 437 font
• Toolchain built with patches from Nightingale and SerenityOS

History

• MinOS 1 - mostly written in the summer of 2021, C and C++
• MinOS 2 - written a few months ago (mid 2022), in Rust
• MinOS 3 - written now (from August 2022), back in C and C++