Luigi Capogrosso
3.8 KiB
MentOS
What
MentOS, which stands for Mentoring OS, is an open source educational Operating System.
Goal
The goal of MentOS is to provide a project environment that is realisticenough to show how a real Operating System work, yet simple enoughthat students can understand and modify it in significant ways.
Why
There are so many operating systems, why did we write MentOs? It is true, there are a lot of education operating system, BUT how many of them follow the the guide line defined by Linux? Linux shareswith MentOs the same data structures, fields, algorithms, ... it has a sourcecode well documented not requiring hours to be compiled on your laptop! MentOS team aimed at this, you can download MentOS and you are readyto start in a few minutes, search any its data structure with Google, and you will find it in Linux.
Developers
Main Developers:
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
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
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
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