Luigi CapogrossoMentOS
1 What is MentOS
An educational 32-bit linux-like Operating System, which integrates the basic functionalities of an OS, ideal for an University-level course. MentOS, which stands for Mentoring OS, is the successor of DreamOS, an Operating System developed by Ivan Gualandri, Finarfin and many others, which can be found at https://github.com/inuyasha82/DreamOs.
2 Developers
Main Developers:
- Enrico Fraccaroli (Galfurian)
- Alessando Danese
- Luigi C.
- Mirco D.
3 Prerequisites
For compiling the main system:
- nasm
- gcc
- g++
- make
- cmake
- git
To run and try:
- qemu-system-x86
For debugging:
- ccmake
- gdb or cgdb
- xterm
4 Compiling MentOS
Compile and boot MentOS with qemu:
cd <clone_directory>
mkdir build
cd build
cmake ..
make all
make initfs
make qemu
If you want to access to the shell, see username and password with:
cd <clone_directory>
cat files/passwd
5 See Booting Statistics
If you want to see more information about memory allocation, process and file system:
cd <clone_directory>
mkdir build
cd build
cmake ..
ccmake ..
Now you should see something like this:
CMAKE_BUILD_TYPE
CMAKE_INSTALL_PREFIX /usr/local
ENABLE_QEMU_DEBUG OFF
You have to set ENABLE_QEMU_DEBUG flag on ON:
select ENABLE_QEMU_DEBUG entry
click enter
click c
click g
There are the instructions of this commands on the bottom of your shell. It is simple to use. Then, like before:
make all
make initfs
make qemu
5 Use Debugger
cd <clone_directory>
Open file .gdb.debug:
nano .gdb.debug
You should see something like this:
symbol-file ./src/mentos/kernel.bin
exec-file ./src/mentos/kernel.bin
target remote localhost:1234
continue
Delete the last line and if you do:
cat .gdb.debug
You should get:
symbol-file ./src/mentos/kernel.bin
exec-file ./src/mentos/kernel.bin
target remote localhost:1234
Now:
cd build
cmake ..
ccmake ..
Set ON the ENABLE_QEMU_DEBUG: see Section 4. Then:
make all
make initfs
make qemu-gdb
If you did everything correctly, you should see 3 windows with:
1) - Kernel Booting on qemu
2) - Shell with video printing of statistics previously discussed
3) - Debugger cgdb with code screening