/mos

A hobby operating system developed from scratch

Primary LanguageCMIT LicenseMIT

mOS

license MIT By Vietnamese

mOS is the unix-like operating system developed from scratch and aims to POSIX compliant.

Work-in-process features

  • Filesystem
  • Program loading
  • UI (X11)
  • Log
  • Networking
  • Signal
  • Terminal
  • mOS toolchain
  • Port figlet
  • Libc
  • Port GNU Bash, Coreutils
  • Unit testing
  • Dynamic linker
  • Port GCC (the GNU Compiler Collection)
  • Browser
  • Sound
  • Symmetric multiprocessing

🍀 Optional features

  • Setup 2-level paging in boot.asm

Get started

MacOS

  • install packages

    $ brew install qemu nasm gdb i386-elf-gcc i386-elf-grub bochs e2fsprogs xorriso

  • open your bash config and add lines below. Depends on your bash, config file might be different. I use ohmyzsh, so it is .zshrc

    # .zshrc
alias grub-file=i386-elf-grub-file
alias grub-mkrescue=i386-elf-grub-mkrescue

  • run emulator

    $ cd src && mkdir logs
$ ./create_image.sh && ./build.sh qemu iso

  • open another terminal

    $ cd src
$ gdb isodir/boot/mos.bin
# in gdb
(gdb) target remote localhost:1234
(gdb) c

✍🏻 If you get this error hdiutil: attach failed - no mountable file systems, installing extFS for MAC might help

Ubuntu

  • Install packakges

    $ sudo apt install build-essential autopoint bison gperf texi2html texinfo qemu automake-1.15 nasm xorriso qemu-system-i386

  • Install gcc cross compilier via https://wiki.osdev.org/GCC_Cross-Compiler#The_Build

  • Install GCC (Version 9.1.0) & Binutils (Version 2.32).

  • Open src/toolchain/build.sh and modify SYSROOT and PREFIX variables to fit in your case

    PREFIX="$HOME/opt/cross"
TARGET=i386-pc-mos
# SYSROOT cannot locate inside PREFIX
SYSROOT="$HOME/Projects/mos/src/toolchain/sysroot"
JOBCOUNT=$(nproc)

  • Install mos toolchain

    $ cd src/toolchain
$ ./build.sh

  • Run Emulator

    $ cd src && mkdir logs
$ ./create_image.sh
$ cd ports/figlet && ./package.sh && cd ../..
$ cd ports/bash && ./package.sh make && cd ../..
$ cd ports/coreutils && ./package.sh make && cd ../..
$ ./build.sh qemu iso

  • Open another terminal

    $ cd src
$ gdb isodir/boot/mos.bin
# in gdb
(gdb) target remote localhost:1234
(gdb) c

✍️ To get userspace address for debugging

$ i386-mos-readelf -e program
# find the line below and copy Addr
# [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
# [ x] .text             PROGBITS        xxx      xxx    xxx    00 AX   0   0  4

Unit Test

$ cd test && git clone https://github.com/ThrowTheSwitch/Unity.git unity
$ make clean && make

Debuging

in build.sh, adding -s -S right after qemu to switch to debug mode. Currently, I use vscode + native debuge -> click Run -> choose "Attach to QEMU"

Monitoring

by default mOS log outputs to terminal. If you want to monitor via file, doing following steps

# src/build.sh#L71
-serial stdio
↓
-serial file:logs/uart1.log

$ tail -f serial.log | while read line ; do echo $line ; done

✍🏻 Using tail in pipe way to color the output (like above) causes a delay -> have to manually saving in ide to get latest changes

References

Tutorials

Ebooks