* boot.bin - boot sector (stage 1 and 2, total 2k), offset 0x7c00
  * boot.asm - the main boot sector code using:
* kernel.bin - linked kernel with fix start offset 0x8400
  * gdt.asm - the early GDT
  * stage1_functions.asm - real mode functions of the bootloader
  * stage2_functions.asm - protected mode primitive VGA routines
  * switch_mode.asm - early GTD loading and switching from real to protected mode
  * kernel.c - Kernel C entry point 'entry'
* magic.bin (512 bytes magic marker sector)
  * magic.asm

kernel utility routines
* console.c - the kernel console, can use VGA or serial port for now
* vga.c - VGA basic output routines for early kernel output
* serial.c - serial output to COM1 (only sequential ASCII chars, no terminal)
* port.c, port.asm - I/O ports

C library routines
* string.c
* stdlib.c