This is an x86_64 operating system written from scratch in C and assembler. It consists of a boot loader, a 64-bit long-mode kernel, and a round-robin scheduler. The userspace programs are loaded directly from disk as there is no filesystem. The kernel includes a vga 80x25 terminal. User progs take argc/argv. There is a basic userspace shell. Newlib is used as a C library for userspace. I've also ported to 64-bit and simplified an ATA driver called MINDRV, it's hardwired to file descriptor three in userspace and supports both DMA- and PIO-based disk I/O.

Most tutorials and resources only cover 32-bit intel systems. I took the time to build everything with 64-bit support from the ground up. I relied a lot on #osdev, too. You might check this project out if you are looking for a simple functioning example of 64-bit intel OS, as i found many resources incomplete or incorrect when i built it.

Syscall interface includes:

• sbrk
• exit
• sleep
• read (stdin and ata disk)
• write (stdout only)
• spawn (run static user prog from startup image)
• wait
• getpid

1. sudo port install qemu x86_64-elf-gcc nasm Note that the nasm included with the Xcode command-line tools is extremely outdated and will not build this project properly.
2. make (the kernel is a flat binary called bigboot)
3. make run (to test in qemu)

The bochs installation from macports does not have x86_64 support, you will need to compile your own

If on mountain lion, first install XQuartz from http://xquartz.macosforge.org/landing/ This will give you an X server.

Then, install some prequisites and build bochs and an elf gdb

sudo port install gtk2
curl -OJL http://sourceforge.net/projects/bochs/files/latest/download?source=files
tar xvf bochs-$VERSION.tar.gz
cd bochs-$VERSION
CFLAGS=-I/opt/local/include LDFLAGS=-L/opt/local/lib ./configure \
--enable-all-optimizations --enable-cdrom --with-x11 \
--enable-x86-64 --enable-debugger  
make
sudo make install
sudo install bochs /usr/local/bin/bochs-native-debugger

# And if you'd like gdb stub support
CFLAGS=-I/opt/local/include LDFLAGS=-L/opt/local/lib ./configure \
--enable-all-optimizations --enable-cdrom --with-x11 \
--enable-x86-64 --enable-gdb-stub
make
sudo install bochs /usr/local/bin/bochs-gdb-stub

sudo port install gmp libelf
curl -OJL http://ftp.gnu.org/gnu/gdb/gdb-7.6.tar.gz
tar xvf gdb-7.6.tar.gz
cd gdb-7.6
mkdir build
cd build
../configure  --prefix=/usr/local --program-prefix=x86_64-elf-
--with-gmp=/opt/local --with-libelf=/opt/local
--with-build-libsubdir=/opt/local --target=x86_64-pc-linux-gnu
make
sudo make install

Once everything is set up, you should be able to issue a "make bochs-native" in the source directory and see the bochs debugger console. If you compiled gdb support above, you can issue "make bochs-gdb" and connect by running the newly installed x86_64-elf-gdb from the main os source checkout directory (using provided .gdbinit).

Licensed under the Unlicense. You should be able to do whatever you want with this without having to give credit.