> Yes! But could anyone explaing to me why it is must be less than 512kb??
The boot loader doesn't run in protected mode. It runs in a 8086 compatible mode that the pc BIOS set up. The cpu can only address 640kB of memory in this mode. Some of this space is needed for the boot loader itself, so there's about 512k left over. The boot loader must load the kernel into this space. Then the kernel switch to protected mode and uncompress itself, using all the available memory. Fortunately, this is not a problem at all. Use modules! I have made everything modules, except for ext2 and the aic7xxx driver I need for the root file system. All other drivers, all other filesystems are modules. Those who don't want modules must make a kernel with less features, or write a boot loader capable of using protected mode. This is not trivial. Helge Hafting
