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

This OS only supports x86

In this lab, you will learn about how to make os support symmertric multiprocessing (SMP) and simple scheduling policy for SMP.

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

New source to be added

• kern/cpu.h Kernel-private definitions for multiprocessor support
• kern/mpconfig.c Code to read the multiprocessor configuration
• kern/mpentry.S Assembly-language entry code for non-boot CPUs
• kern/spinlock.h Kernel-private definitions for spin locks, including the big kernel lock
• kern/spinlock.c Kernel code implementing spin locks
• kern/lapic.c Kernel code driving the local APIC unit in each processor

Modifications to be made

• inc/syscall.h Implement get_cid
• kernel/main.c Implement boot_aps and mp_main to support multiprocessor
• kernel/task.c Implement task_init_percpu and modify variable cur_task, functions sys_fork sys_kill to support multiprocessor
• kernel/syscall.c Implement get_cid
• kernel/sched.c Modify scheduler to support multiprocessor
• kernel/timer.c Modify timer_handler to support multiprocessor
• kernel/mem.c Implement mmio_boot_region,mem_init_mp and modify page_init to support multiprocessor Modify check_page_free_list,check_kern_pgdir and check_page to check new feature

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

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

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

This is forked and modified from MIT's Xv6