bootsector, FAT12

C++ static constructors, calling before main()

CPU,

• check for 32-bit CPU

client (network) demo code,

• TCP (HTTP)
• UDP

cooperative multitasking with setjmp() and longjmp()

data segment, test if kernel linked and loaded properly

discardable kernel code and data

disks,

• getting count of drives known to the BIOS
• sector-level disk I/O under different OSes

Energy Star monitor, idling

filenames, testing for illegal

floppy,

• turn off motor(s)
• probe sectors-per-track value (C)
• probe sectors-per-track value (NASM)

GDT, patching linear address in GDT pseudo-descriptor

IDE hard disk, idling

graphics,

• 2D demo code (line, rect, text blit, etc.)
• set VGA graphics mode without BIOS

interrupts,

• 8259 programmable interrupt controller (PIC) chips,
  • enabling and disabling interrupts at 8259 chip
  • EOI (End Of Interrupt), to acknowledge IRQ at the 8259 chips
  • reprogramming to assign IRQs to non-reserved interrupts
• acknowledging IRQ at other chips
• demo code
• saving ring 0 ESP before IRET to ring 3

keyboard,

• interrupt-driven driver code/demo (C)
• polled keyboard input (asm)

LEDs on keyboard, controlling

malloc, simple

memory size, determining

• using BIOS calls
• using CMOS

PCI devices, detecting

• using 16-bit BIOS calls or direct probing
• using 32-bit BIOS calls or direct probing

PIC,

• (position independent code) asm kernel startup code, before paging is enabled
• (programmable interrupt controller) see 8259 chip

PnP devices, detecting

• using 16-bit BIOS calls
• using 32-bit BIOS calls
• using direct probing

printf(), simple

protected mode,

• quick-start code
• return to real mode

relocatable (.o) file, load and run

reset/reboot PC via keyboard controller

ROMs, detecting

server (network) demo code,

• TCP (HTTP)
• UDP

socket code for DOS programs running under Win95

timer chip (8253), reprogramming

underscores,

• NASM macros for
• on symbols emitted by DOS/Windows compilers

unreal mode, enabling

video,

• checking if VGA set for color or monochrome emulation
• moving cursor
  • using INT 10h AH=02h
  • by poking VGA registers
• scrolling
  • software
  • hardware
• text output
  • doesn't work?
  • using BIOS
    • using INT 10h AH=0Eh
    • using INT 10h AH=13h
  • poking characters directly into the text-mode framebuffer

virtual 8086 mode

• check if CPU in virtual 8086 mode
• use VCPI to switch from virtual 8086 mode to real mode