_purpOSe

Operating System project

Info

Author: Marek Machliński

Project start: 24.03.2019

Documentation: Doxygen

Project structure

Directory	Overview
cross	Sources and headers for platform independent code.
makeconfig	Configuration files included to main makefile.
makeconfig/rules	Rules for compilation of every folder in project structure.
utils	Utility scripts and tools needed to automate build process and instalation of cross-compiler.
utils/quick_tools	Sources and compiled tools that help during build process.
x86	Sources and headers for x86 specyfic code.

Build process

Creation of toolchain

Compilation process needs specyfic toolchain to create OS for desired architecture. Below scripts were made to automate this process:

• setup.sh - Creates all components needed to start working on project. If some packages needs to be installed first, proper message will appear.
• utils/install_env_tools.sh - If you need to install only cross compiler run this script.
• utils/install_quick_tools.sh - After creation of new tools or editing existing ones run this script to recreate them.

WARNING! All tools are meant to be run from project root directory. To avoid unexpected and devastating behaviour newer run them from any other directory!

Project compilation

After creation of toolchain GNU Make is used to compile project. Not specifying any target will create disk images for all supported architectures. Typing architecture name will create image only for that target. Supported architectures:

• x86

Makefile structure

File	Overview
makefile	Main file containing tools locations and main rules for each module and architecture.
makeconfig/directories.mk	Variables ending with _DIR specifying directories for each module and SYSROOT directory.
makeconfig/files.mk	Variables ending with _OBJ and _SRC containing all object and source files for specyfic modules.
makeconfig/flags.mk	Variables with flags needed for compilation of specyfic target architectures. Variables here ends with _FLAGS, _INC or _DEFINES (only for OS specyfic defines).
makeconfig/rules.mk	Summary file containing includes of pattern rules for each module and directory in source tree. When creating new module add it's includes here.
makeconfig/rules/*	Location of pattern rules for each module and language. This files have to be included to makeconfig/rules.mk. When adding new module simply create new file for each language that this module will be made of. When creating new directories in source tree add new rule in one of module files here to compile files in newly created catalog.

Code conventions

To unify code style here are rules followed by this project:

• Makefile variables are named with ALL_CAPS.
• Macro, constants, global variables and defines are named with ALL_CAPS.
• Functions and variables are named with snake_case.
• Assembly functions have to be preceded with '_'.
• Structures and other data types are named with PascalCase.
• Enum types are named with snake_case preceded with enum name, ex. enum MyColor { MyColor_light_blue }.
• Avoid short names, let every function describe itself but don't make them too long. For header functions that MAY (think twice) need additional description, add comment.
• Every assembly funtion needs to be in seperate file. Only bootloader is exception.
• Try to keep not connected functions in seperate files when possible. If so for every header create directory containing such functions with same name as header file.
• No space before asterisks or ampersands and one after in type declarations.

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Tips:

• Do not git clone into directory tree which includes whitespaces.