peterzsigmondOS

A very basic x86 OS. It includes some images, and a terminal, where the users can write their own hex coded x86 instructions, which then the OS can run. Theoretically, with this terminal, any task can be done on a computer.

Screenshots

Build

Install NASM:

apt/brew install nasm

Then build with:

nasm -f bin src/os.asm -o build/os.bin

Run

With Qemu:

Install on Linux:

apt install qemu-system

Install on Mac:

brew install qemu

Then run:

qemu-system-x86_64 -drive format=raw,file=build/os.bin

On bare-metal:

Copy it on a flash drive:

dd if=build/os.bin of=</dev/disk>

...then boot from it.

Terminal

Write hex coded x86 instructions in the Terminal, and press enter to run them. To call a function, that prints out the processor brand, type in:

B8 00 84 FF E0

...which actually is:

mov ax, 0x8400
jmp ax

Binary maps

build/os.bin:

0x00000 - 0x001ff = Bootloader       (512 byte,     1 sector)
0x00200 - 0x005ff = OS               (1.024 byte,   2 sector)
0x00600 - 0x007ff = String consts    (512 byte,     1 sector)
0x00800 - 0x009ff = CPU info printer (512 byte,     1 sector)
0x00a00 - 0xc03ff = Images           (784.896 byte, 1533 sector)

Total: 769 kB

Memory map:

0x07c00 - 0x07dff = Bootloader       (512 byte,     1 sector)
0x07e00 - 0x081ff = OS               (1.024 byte,   2 sector)
0x08200 - 0x083ff = String consts    (512 byte,     1 sector)
0x08400 - 0x085ff = CPU info printer (512 byte,     1 sector)
0x08600 - 0x087ff = General memory   (512 byte,     1 sector)
0x08800 - 0x0af0f = Stack            (10.240 byte,  20 sector)
0x0af10 - 0x2650f = Image            (112.128 byte, 219 sector)

Total: 122.5 kB