nctuOS

A tiny OS that used for course OSDI in National Chiao Tung University, Computer Science Dept.

This OS only supports x86

Lab 5

In this lab, you will learn about process management, basic scheduling and system calls.

In our design, each process contains a page directory so that each of them can have full memory addressing space.

For each process, there are several attributes that are necessary for kernel to manage the process easily, you can reference kernel/task.h for more detail.

Source Tree

kernel/*: Includes all the file implementation needed by kernel only. lib/*: Includes libraries that should be in user space. inc/*: Header files for user. user/*: Files for user program. boot/*: Files for booting the kernel.

You can leverage grep to find out where to fill up to finish this lab.

$ grep -R TODO .

To run this kernel

$ make
$ make qemu

To debug

$ make debug

Modifications to be made

• lib/syscall.c implement the interfaces of system calls for user program to use.
• kernel/task.h to open interfaces of implementation of system calls for kernel/syscall.c
• kernel/task.c implement task_create, task_free, sys_kill, sys_fork, and task_init
• kernel/syscall.c implement system calls
• kernel/trap_entry.S implement trap handler interface for system call
• kernel/mem.c implement setupkvm used by each process creation
• kernel/sched.c implement scheduler
• kernel/timer.c implement timer_handler to support sleep

Lab 4

In this lab, you will learn about memory management in x86.

You can leverage grep to find out where to fill up to finish this lab.

$ grep -R TODO .

To run this kernel

$ make
$ qemu -hda kernel.img -monitor stdio

• Modify kernel/mem.c to implement the memory management functions
• Modify kernel/trap.c and kernel/trap_entry.S to setup IDT for pagefault

Lab 3

In this lab, you will learn about interrupt and segmentation mechanism in x86.

We provided you with keyboard handler, timer handler, and simple VGA driver.

You can leverage grep to find out where to fill up to finish this lab.

$ grep -R TODO .

To run this kernel

$ make
$ qemu -hda kernel.img -monitor stdio

• Modify boot/boot.S to setup GDT
• Modify kernel/trap.c and kernel/trap_entry.S to setup IDT for keyboard and timer
• Modify kernel/main.c to uncomment the setup process
• Modify kernel/shell.c to support kerninfo and chgcolor

After this lab, you should know about how interrupt works and the working flow of GDT & IDT

Acknowledgement

This is forked and modified from MIT's Xv6