PolyB/toy-bootloader

a toy bootloader

build and run

make
qemu-system-x86_64 -enable-kvm -fda boot.bin -nographic -serial stdio -monitor none

bootloader

bootloader stages

shared

contains the global value and headers shared between bootloader stages and the kernel

stage1 (real mode - 16bit)

this is the first 512 octets of the bootloader, it's purpose is to load the next stages of the bootloader

• read the stage2 from the floppy disk
• execute stage2
• overwrite the stage2 with the stage3
• execute stage3

stage2 (real mode - 16bit)

execute the 16bit tasks

stage3 (protected-32)

enter 32bit mode (stage3/start.S)

execute the 32bit tasks

One of the task is read from the floppy disk the loader_protected in memory

the stage ends by jumping on loader_protected

loader_protected (protected-32)

this stage just reads the stage 4 and 5 from the floppy disk and execute them

stage4 (long-32)

the stage4 loads the datas nessesary for 64bit long mode

stage5 (long-64)

the stage5 is long-64 mode, the kernel is here.