Most linux drivers are configured to provide pointers to functions to higer levels of the OS. This makes it easy to exchange drivers. For example the OS calls fb_mmap which in our case is a pointer to mcffb_mmap.
mcf-fb.c declares structs fb_info and fb_ops. The mcffb_ops struct is declared to have pointers to various functions within the driver. fb_info has a pointer which is set to the mcffb_ops. mcffb_init calls register_framebuffer passing a pointer to the info structure. This tells the higher level OS routines what functions to use to talk to the hardware.
You might check out the book Linux Device Drivers by Alessandro Rubini & Jonathan Corbet.
If you use the defaults assuming login "user" you should have ltib in /home/user/ltib-cf_nommu-20081215.
After doing ./ltib -m prep -p kernel you should have /home/user/ltib-cf_nommu-20081215/rpm/BUILD/linux-2.6.26/drivers/input/touchscreen This directory contains ads7843.c which is the touchscreen driver used by the mcf5329evb.
/home/user/ltib-cf_nommu-20081215/rpm/BUILD/linux-2.6.26/drivers/video contains mcf-fb.c which is the frame buffer driver.
There is a file ltib-install-dir/doc/LtibFaq that is somewhat helpful. Look for "How do I make changes to a package and capture them".
I don't know of any ftp server to download the driver source. I use Fedora and mount to a windows shares such as:
mount -t cifs //192.168.1.1/SharedDocs /mnt/share -o user=xyz,password=abc
You can also edit fstab so it mounts automatically.
I would think you can do this with Debian.
You can download the BSP. http://www.freescale.com/webapp/sps/site/overview.jsp?nodeId=0127260061033202A9
You may alter the timing on the drivers/video/mcf-fb.c for your LCD.
./ltib -m prep -p kernel
This will put the kernel source in <ltib directory>/rpm/BUILD/kernel
You don't have to use prep again.
You can then make changes to the driver souce and either use ./ltib -c and go through the menus or
./ltib -m scbuild -p kernel
./ltib -m scdeploy -p kernel
If you want to work on the source code for another package such as busybox do the same replacing kernel with busybox.
The documentation isn't very clear about this; when I started with it it took me a while find this.