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Boot Process

Baptiste Wicht edited this page 2014-01-21 11:28:25 -08:00

Edit: Now the bootloader loads the kernel directly from the disk in FAT32.

TODO Review this page.

More up to date version: http://www.baptiste-wicht.com/2013/12/thor-os-boot-process/

The boot of the operating system is made in several steps:

1. The bootloader (ASM) is started from 0x07C0 in memory
2. The bootloader reads the second sector of the floppy, loads it at 0x900 and jumps to it
3. The second step bootloader (ASM) loads the operating system from the floppy, loads it at 0x1000 and jumps to it
4. The kernel goes into protected mode, loads the GDT, goes into long mode, loads the IDT and setup ISRs and IRQs handlers and then it is ready for normal usage
5. The kernel init the PIT and the keyboard and displays a shell. It is also responsible for configuring paging for dynamic memory allocation.