This repository contains the Linux source code for CSC 256/456.

Students will need the OpenWRT hard disk image. The getfiles.sh script will download and unpack these files from the course web page. In case students want to get the files by hand, the information is below:

o The OpenWRT image that we use for our virtual machine is at http://www.cs.rochester.edu/courses/256/fall2015/QDGL/openwrt-15.05-x86-generic-combined-ext4.img

To compile the kernel, cd into the linux-3.18.77 directory. Use the following commands the first time you build the kernel:

o make mrproper

o cp csc256.config .config

o make bzImage

Subsequent kernel compiles can be done just by using:

o make bzImage

The first kernel compile will take some time. Subsequent kernel compiles will take less time as the kernel build system will only recompile files that have changed (or that use header files that have changed).

If your system has multiple processors, you can use the -j option to GNU make to compile files in parallel. Just remember to be kind to your fellow students don't specify too large a number with the -j option.

The runqemu.sh script will launch QEMU with the needed command-line options. With no arguments, it will boot the OpenWRT disk image with the default kernel residing on the image. Alternatively, students can provide the pathname to their Linux kernel, and runqemu.sh will boot their kernel instead. The kernel is in the file linux-3.18.77/arch/x86/boot/bzImage.

Files in the floppy directory will appear as a hard disk within the virtual machine. To mount the hard disk, use the command:

o mount -t msdos /dev/sdb1 /mnt

The contents of the directory floppy should appear in /mnt.

Be sure to use the following command to unmount the hard disk device before shutting down the virtual machine:

o unmount /mnt