cirosantilli/x86-bare-metal-examples

Features

• Bare-Metal Runtimes - Provides a collection of minimal operating systems and bootloaders for low-level x86 system programming.
• System Programming Labs - Offers a collection of minimal binaries for testing x86 architecture concepts and hardware behavior in QEMU.
• Hardware Exception Handlers - Implements low-level hardware exception handlers to capture and respond to processor interrupts.
• BIOS Firmware Interfaces - Implements screen output, disk reading, and keyboard input by invoking BIOS firmware routines.
• Boot Sector Loaders - Implements a boot manager that locates and executes secondary boot sectors on disk partitions.
• Multi-Stage Loading - Reads additional sectors from disk into memory and transfers execution to secondary boot stages.
• Bootable Image Generation - Generates minimal x86 disk images with mandatory magic bytes for BIOS recognition.
• CPU Register Initialization - Sets up essential segment registers and disables interrupts to ensure a consistent execution environment.
• Firmware Text Output - Provides routines to output characters and strings using BIOS interrupts and VGA video memory.
• Bootable Image Creation - Creates the smallest possible x86 executable that the system BIOS can recognize and boot.
• x86 Bootloaders - Includes detailed examples for creating x86 bootable disk images and loading kernel stages.
• Memory Segmentation - Implements memory segmentation and configures the Global Descriptor Table (GDT) for memory isolation.
• Interrupt Controller Initializations - Configures and remaps the PIC interrupt controller vectors to avoid conflicts with CPU exceptions.
• Interrupt Vector Handlers - Defines an Interrupt Descriptor Table to map hardware and software vectors to specific handler functions.
• Interrupt Descriptor Tables - Defines an Interrupt Descriptor Table to map hardware interrupts to handler functions.
• Page Fault Handlers - Intercepts memory access violations using an Interrupt Descriptor Table to resolve page faults.
• Processor Mode Transitions - Implements the transition from 16-bit real mode to 32-bit protected mode using the Global Descriptor Table.
• Symmetric Multiprocessing Mechanisms - Implements kernel-level symmetric multiprocessing mechanisms to boot and synchronize multiple CPU cores.
• Virtual Memory Mapping - Maps virtual addresses to physical memory frames using a multi-level page table structure.
• x86 Kernel Implementations - Provides reference implementations for x86 protected mode, paging, and symmetric multiprocessing.
• Native Binary Toolchains - Provides a toolchain to compile assembly source into flat binary images for direct hardware execution.
• Remote Hardware Debugging - Enables connecting an external debugger to an emulated system to set breakpoints and inspect low-level state.
• Serial Port Interfaces - Initializes serial port hardware by configuring baud rates and data bits for communication.
• Hardware Timer Controllers - Configures the Programmable Interval Timer to generate periodic interrupts for system timing.
• CPU Register Inspection - Includes tools for reading and printing the initial CPU register values provided by the system firmware.
• BIOS Disk I/O - Reads specific disk sectors into memory using BIOS interrupts to transfer data into system memory.
• Disk Installers - Writes bootloader configuration to a hard disk and updates the Master Boot Record.
• Kernel Loading Mechanisms - Loads and executes multiboot-compliant ELF files from the boot menu.
• Kernel Memory Layouts - Defines memory addresses and section alignments to ensure the hardware loads the kernel at the correct location.
• Multiboot Standard Implementations - Uses the Multiboot standard to load ELF kernel images into memory while bypassing custom bootloader stages.
• Physical Memory Mapping - Queries the hardware to determine available and reserved physical memory regions.
• PS/2 Keyboard Drivers - Reads character scancodes from the keyboard controller using polling and interrupts.
• Serial Port Drivers - Provides a bare-metal driver for transmitting text characters via the hardware serial port.
• VGA Text Buffer Drivers - Writes characters and colors directly to the memory-mapped video buffer to bypass BIOS firmware.
• Hardware Emulators - Supports executing and testing compiled binary images within a hardware emulator to simulate x86 architecture.
• Binary Compilation - Compiles assembly source code and links it using a custom script to create raw binary images.
• Cheat Sheets - Listed in the “Cheat Sheets” section of the The Book Of Secret Knowledge awesome list.

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