General Assignment guidelines

Changes will be highlighted in green
Important notices will be highlighted in yellow
Assignments have to be strictly submitted according to guidelines. (will be put up later)
Assignments can be done in groups of two. lone wolves will be given some extra credit.

Assignment on OSkit and Bochs

Part 1 : Porting

Port Assignment 1 (pthreads part) to run on Bochs with the following changes:
- Replace the track with a 3 lane circuitious lap
- Cars do a busy wait instead of sleep (to notice the effects of scheduling)
- Use the VGA bios functions as detailed instead of ncurses
- Notes on running vga bios
  - A Basic tutorial
  - Note that inline assembly in gcc can be incorporated using the asm directive. Also Gnu assembler uses AT&T syntax and not intel assembly syntax
  - Pointers to inline assembly in gcc
  - Further Pointers
- You MAY also use vga mode (and the svgalib library) to render the screen. note that the standard svgalib does not work. An altered svgalib (cheers! to soumyadeb) and an example C file and Makefile may be downloaded from the link below. NOTE THAT you may need to change some paths to oskit in the Makefile. I have compiled it on chhaya so should be ok in the intel cluster.
  vga test
- Also, the followinf list of commands needs to be executed before you run bochs:
  - mkdir .fonts
  - cd .fonts
  - cp /usr/local/bochs-2.0.2/share/bochs/vga.pcf .
  - mkfontdir
  - xset +fp `pwd`
  - xset fp rehash
  This would remove errors of the type 'vga font not installed, etc'
- Also make sure you run bochs-2.0* from /usr/local in the cluster
- Use the OSkit threads library and mutexes etc.
- Use the Oskit schedulers : round robin, priority

Part 2 : Concurrent programming

put in collision detection alongwith some primitive AI in the cars (faster car changes lane to overtake etc. )
implement your own semaphores (AS SYSTEM CALLS)

Part 3 : Schedulers

Run the code on your own schedulers : implement the following
- round robin
- Priority Scheduler
- some weird scheduler which schedules the cars in such a way that th no two cars are more than one lap apart (i.e. slower cars are scheduled more frequently etc.)

Background Reading

Read the documentation of Bochs (a free X86 emulator) and OSKit. Check out the Bochs and OSKit documentation mirrored locally.
Soumyadeb's pointers to OsKit
svgalib tutorial

Tips

Run the hello world program on bochs first
Booting from your kernel
Getting the bootable image - You will find the image of a bootable floppy called floppy.img here. The image has a bootloader in it. The bootloader automatically loads the kernel excutable called kernel (what else !!!). Copying your kernel image onto a floppy -
- Method 1 : Use dd to get the image onto a floppy. Copy your kernel onto the floppy (naming it 'kernel' of course) and again create an image of the floppy using dd. This image can now be used by BOCHS.
- Method 2: Mount the image as a loopback device onto say /mnt/floppy using this command mount floppy.img /mnt/floppy -o loop. Now you can access it as a normal floppy and copy your kernel onto it. Check out man mount for more infomation on the loop option.

login to these machines, do a mount /mnt/floppy.img
cd /mnt/floppy.img
Replace the kernel file with your own kernel
umount /mnt/floppy.img
cp /tmp/floppy.img ~
Use this floppy.img to run bochs.

REMEMBER to umount the floppy even if you don't need to use it right away. You will be penalised on violation

Alternative assignment : make the bouncing ball setup run on box
Details:
check out the attraction (balls) screensaver present in linux.
Note : this should be sufficiently complex to impress the evaluators.

Last date for submission:

Part 1: Tuesday,30th Sep. 2003

Part 2: Sunday 12th Oct. 2003

Part 3: Wednesday 29th Oct. 2003

Click here to submit part 3