emulate floppy in linux

So I was trying to write a "hello world" "OS" and then add more functionality to it.. just to try it out.

My colleague had showed me a nice link osdev.org. quite intersting resource regarding os development. There they had tutorials on how to get started.

I found this to be a very nice link to get me started:
http://www.osdever.net/downloads.php

One of the steps involved making a boot floppy with grub etc installed on it. Now I was using vmware and didnt hava floppy drive. So I knew I could use dd to create an image and then change the image's filesystem. Just didnt konw how exactly. So my co-worker gave this!

# create a image of Zeros of length 2048 bytes
dd if=/dev/zero of=floppy.img bs=1024 count=2048

#make the image of ext2 file system
mkfs.ext2 floppy.img

#create a mount point
mkdir floppy.d

#mount the image to the mount point
mount -o loop floppy.img floppy.d


Now you can treat the floppy.d directory as a floppy drive! and then unmount when done and transfer the image anywhere!



works like a charm :)

chroot after rsync

So I had a fedora core 6 box 64 bit that I needed to set up as a build box. t needed to build:

Redhat4 32 bit
Redhat4 64 bit
Redhat5 32 bit
Redhat5 64 bit

So now I had a few options to choose from,
- have 2 chroots' /redhat4 and /redhat5 and then chroot to redhat4 and build 32 and 64 bit drivers and repeat the process for /redhat5

OR
- have 4 chroots' and keep each build seperate. so I would have /redhat4_32 /redhat4_64 /redhat5_32 and /redhat5_64

Going the first route meant I would have to propagate the architecture all the way from top level build initiating script down to all the sub projects. The second option seemed better over the long run.


So the process is pretty simple. The over all steps are as follows:

systems:
gandalf - the box that needs to have whole build environment
boromir - temporary vmware image that will be deleted later. (as boromir does die!)

1- install redhat4 32 bit on boromir
2- create /redhat4_32 dir on gandalf
3- copy all the files from boromir to gandalf:/redhat4_32
4- set up the appropriate mounts for /proc and /dev
5- thats it.. chroot into /redhat4_32 on gandalf

vmware to qemu convert

So we were developing drivers for solaris 10 at our company. Since we didnt have nough sparc machines, most of the dev happened on our vmware x86 solaris boxes. My co-worker (from whom I have learnt more aobut linux in the last 8 months than I learnt in the last few years on my own) showed me the way to convert the VMware image to qemu image. Without further ado, here is the command

qemu-img convert /mnt/1/Solaris10.x86.64/Sol_x86_64.vmdk -O qcow solaris-10-64bit.img