mOS
mOS is the UNIX-like operating system developed from scratch and aims to be 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
- 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. Depending on your bash config, the 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
βπ» 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
$ 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
Debugging
in build.sh
, adding -s -S
right after qemu
to switch to debug mode. Currently, I use vscode + native debug -> click Run -> choose "Attach to QEMU"
Monitoring
by default, mOS logs output to terminal. If you want to monitor via file, doing following steps
# src/build.sh#L71
-serial stdio
β
-serial file:logs/uart1.log
$ tail -f serial.log | while read line ; do echo $line ; done
βπ» Using tail
in pipe way to color the output (like above) causes a delay -> have to manually save in the IDE to get latest changes
References
Tutorials
- http://www.brokenthorn.com/Resources
- http://www.jamesmolloy.co.uk/tutorial_html/
- https://wiki.osdev.org