ashrithhc / lateos Goto Github PK

Operating System implementation as a course project for CSE 506 under Prof. Mike Ferdman. It has Cooperative multi-tasking with below functionalities :

1. All functions from include/*.h must work
2. Virtual memory/ring-3 user processes
3. COW fork(), auto-growing stack, graceful SEGV
4. tarfs: open, read, close, opendir, readdir, closedir
5. read(stdin), write(stdout), write(stderr)
6. Binaries: echo, sleep, cat, ls, kill -9, ps
7. Command prompt - sbush

1. Memory Subsystem (page descriptors, free list, page tables, kmalloc)
2. rocess Subsystem (kernel threads, context switch)
3. User-level Subsystem (VMAs/vm_map_entrys, switch to ring 3, page faults)
4. I/O subsystem (syscalls, terminals, VFS, tarfs file access)
5. Implement /bin/init (call fork()+exec()+wait() on /etc/rc, then exec() sbush)

1. builds a kernel
2. copies it into rootfs/boot/kernel/kernel
3. 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

OSdev.org

Browseable modern OS source codes

GCC Inline Assembly

x86_64 calling conventions

How statically linked programs run on linux

GDB Tutorial

GNU Public License v3.0

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.