Comment 10 for bug 260608

The initial reading is done by the bios, a small program that lies in the permanent memory of the computer. It knows where to look for the bootloader in the CD, but this gives full control to the initramfs kernel, which needs to load nodules to be able to access the hardware parts (something like this, I'm not such an expert on these issues so I may be wrong in the details...).

Sometimes the same issue can happen in hard disks as well, the bootloader will load but then the actual kernel does not know how to access a particular kind of hard drive.