clibmini

clibmini is a minimal, self-contained replacement for parts of the C standard library, intended for use in low-level environments such as operating system kernels, bare-metal development, embedded systems, or educational OS projects. I wrote this as part of my kernel/OS development project targeting ARM64 architecture on Raspberry Pi hardware. Below is tiny demo clip demonstrating the code working in my kernel/OS dev project:

kernel_demo.mp4

Features

• Custom print function supporting:
  • %d, %u, %f, %s, %c, %x, and %X format specifiers
• Lightweight implementations of:
  • strlen
  • strncpy
  • Integer and unsigned integer to string conversion
  • Floating point to string conversion
  • String copying utilities

Goals

• Provide a minimal set of core functionality without requiring a full C standard library
• Avoid heap allocation and system-specific dependencies
• Be easy to understand and modify for low-level development

Example Usage

print("Integer: %d, Hex: %x, Float: %f\n", -42, 255, 3.1415);

File Overview

• clibmini.h — Header file declaring all functions
• clibmini.c — Implementation of string utilities and formatted output
• (Optional) main.c or test file — Can be used to test functionality in userspace

Limitations

• print uses printf internally for debug output. This will need to be replaced with a platform-specific output function (e.g., serial or framebuffer) for use in kernel mode or bare-metal applications.
• Floating point support is basic and controlled via fixed precision.
• No support for advanced formatting (padding, width, alignment, etc.)

Future Work

• Implement more standard library functions (memcpy, strcmp, etc.)

License

This project is released under the GNU General Public License v3.0. See LICENSE for details.

Note: This project is designed for learning and experimentation. Contributions and suggestions are welcome!