Operating System implementation as a course project for CSE 506 under Prof. Mike Ferdman. It has Cooperative multi-tasking with below functionalities :
- All functions from include/*.h must work
- Virtual memory/ring-3 user processes
- COW fork(), auto-growing stack, graceful SEGV
- tarfs: open, read, close, opendir, readdir, closedir
- read(stdin), write(stdout), write(stderr)
- Binaries: echo, sleep, cat, ls, kill -9, ps
- Command prompt - sbush
- Memory Subsystem (page descriptors, free list, page tables, kmalloc)
- rocess Subsystem (kernel threads, context switch)
- User-level Subsystem (VMAs/vm_map_entrys, switch to ring 3, page faults)
- I/O subsystem (syscalls, terminals, VFS, tarfs file access)
- Implement /bin/init (call fork()+exec()+wait() on /etc/rc, then exec() sbush)
- builds a kernel
- copies it into rootfs/boot/kernel/kernel
- creates an ISO CD image with the rootfs/ contents
qemu-system-x86_64 -curses -drive id=boot,format=raw,file=$USER.img,if=none -drive id=data,format=raw,file=$USER-data.img,if=none -device ahci,id=ahci -device ide-drive,drive=boot,bus=ahci.0 -device ide-drive,drive=data,bus=ahci.1 -gdb tcp::9999
Explanation of parameters: -curses use a text console (omit this to use default SDL/VNC console) -drive ... connect a CD-ROM or hard drive with corresponding image -device ... configure an AHCI controller for the boot and data disks -gdb tcp::9999 listen for "remote" debugging connections on port NNNN -S wait for GDB to connect at startup -no-reboot prevent reboot when OS crashes
When using the -curses mode, switch to the qemu> console with ESC-2.
gdb ./kernel
At the (gdb) prompt, connect with:
target remote localhost:9999
Browseable modern OS source codes
How statically linked programs run on linux
Fixing GDB on local machine - Raveendra Soori
We do not provide support for it, but you can get your own usable environment for the course projects up and running by installing Ubuntu 16.04 and:
apt-get install build-essential gdb git screen tmux emacs exuberant-ctags ccache eclipse xterm gtkwave tcl-dev zsh strace curl mkisofs qemu dosfstools syslinux
If you are working on your own machine, you will need to build gdb from source and apply a patch.