bootloaders.txt

’’This document contains the loading scheme for MOS kernels’’

Summary
bootloaders.txt‘’This document contains the loading scheme for MOS kernels’’
Diagrams
x86/ amd64 Bootloader ArchitectureThis is how the boot sequence is organized on a PC-based system

Diagrams

x86/ amd64 Bootloader Architecture

This is how the boot sequence is organized on a PC-based system

            ******** Supplied Bootloader ***
* FAT system *
* *
* +---------+ +---------+ *
+--->| Stage 1 |---->| Stage 2 |----------------+
| * +---------+ +---------+ * |
| * * |
+------+ | ******************************** | +---------+ +---------+
| BIOS |-+ +->| Stage 3 |->| Stage 4 |
+------+ | ********* GRUB **************************** | +---------+ +---------+
| * * |
| * +---------+ +-----------+ +---------+ * |
+--->| Stage 1 |->| Stage 1.5 |->| Stage 2 |----+
* +---------+ +-----------+ +---------+ *
* | ^ *
* +---------------------------+ *
* *
*******************************************

The main kernel is located in Stage 3 (<stage3.asm>).  This module is multiboot compliant and can therefore be loaded by any multiboot-compliant bootloader, including GRUB.

A lightweight bootloader is provided to quickly boot from floppy without having to dedicate a large part of the floppy to any boot loader.

When Stage 3 is started, it is supplied with a ramdisk, containing the modules needed.  Also located in this ramdisk is Stage 4 (<stage4.asm>), which is loaded by the kernel and is responsible for loading the rest of the operating system.