jhyunleehi / hello-os

A multiboot OS that prints

These instructions work on Ubuntu 18.04

Prerequisites

• Install Qemu

You can run this boot into Rust demo under Qemu emulator or on baremetal hardware. I suggest to try Qemu first. Install Qemu

sudo apt-get install qemu

• Install nasm

To build the ASM files you'll need nasm:

sudo apt-get install nasm

Run under QEMU

make qemu

If you see complains from the grub-mkrescue, install the xorriso package

grub-mkrescue: warning: Your xorriso doesn't support `--grub2-boot-info'. Some features are disabled. Please use xorriso 1.2.9 or later..                                                 

Debug wigh QEMU and GDB

You will need two shell windows opened in the same folder. In the first shell type:

make qemu

In the other shell start gdb like

gdb

Boot on baremetal from a USB drive

Copy the ISO disk image to the USB stick (make sure to use correct device for the USB drive, otherwise you can overwrite your hard disk). You can use lsblk on Ubuntu to list block devices

lsblk

For me it's /dev/sda or /dev/sdb but my laptop runs off an NVMe device, so for you /dev/sda may very well be your root device, not a USB!

sudo dd if=build/hello.iso of=/dev/<your_usb_drive> bs=1MB
sync

Boot on baremetal from a Linux partition

sudo cp build/kernel.bin /boot/

Add the following entry to the grub menu list. On a Linux machine this can be done by adding this to the /etc/grub.d/40_custom. You might adjust the root='hd0,2' to reflect where your Linux root is on disk, e.g., maybe it's on root='hd0,1'

set timeout=30
menuentry "Hello World" {
    insmod ext2
    set root='hd0,1'
    set kernel='/boot/kernel.bin'
    echo "Loading ${kernel}..."
    multiboot2 ${kernel} ${kernel}
    boot
}

Update grub

  sudo sudo update-grub2

Reboot and choose the "Hello World" entry. Make sure that you can see the grub menu list by editing /etc/default/grub making sure that GRUB_HIDDEN_TIMEOUT_QUIET is set to "false".

  GRUB_HIDDEN_TIMEOUT_QUIET=false