# SUB-OS: 64-Bit Production Modular Monolithic Operating System ```text _____ _ _ ____ ____ _____ / ____| | | | _ \ / __ \ / ____| | (___ | | | | |_) |______| | | | (___ \___ \| | | | _ <|______| | | |\___ \ ____) | |__| | |_) | | |__| |____) | |_____/ \____/|____/ \____/|_____/ ``` [![Architecture](https://img.shields.io/badge/arch-x86__64%20Long%20Mode-blue.svg?style=flat-square)]() [![Kernel](https://img.shields.io/badge/kernel-Modular%20Monolithic-red.svg?style=flat-square)]() [![Version](https://img.shields.io/badge/version-v0.2.0--lts%20(Titan)-purple.svg?style=flat-square)]() [![Userland](https://img.shields.io/badge/userland-LazyBox%20v2.0.0--pro%20%2B%20Nano-orange.svg?style=flat-square)]() [![Networking](https://img.shields.io/badge/network-Intel%20E1000%20Gigabit%20%7C%20IPv4%20%7C%20BSD%20Sockets-green.svg?style=flat-square)]() [![License](https://img.shields.io/badge/license-MIT-lightgrey.svg?style=flat-square)](LICENSE) **SUB-OS** is an open-source, production-grade 64-bit modular monolithic operating system engineered from the ground up for the `x86_64` architecture. Built adhering to the internal design principles of modern UNIX/Linux kernels, SUB-OS features a full bare-metal hardware driver tree, physical and dynamic memory management, a virtual file system (VFS) with FAT32, ext2, sysfs, and devfs, full L2-L4 networking protocol stack with BSD Sockets, cryptographic engine, Linux Security Modules (LSM), asynchronous `io_uring` ringbuffers, Inter-Process Communication (IPC) engine, Text-to-Speech (TTS) voice synthesizer, AC'97 sound architecture, full-screen visual `nano` editor, and the **LazyBox** multi-call userland environment with 50+ Linux utilities. --- ## 🏛️ Comprehensive System Architecture ```text +------------------------------------------------------------------------------------+ | USERLAND & SYSTEM SUITE | | Interactive Shell | GNU Nano 2.0.0 | LazyBox Multi-Call Suite (50+ Coreutils) | +------------------------------------------------------------------------------------+ | VIRTUAL FILE SYSTEM LAYER (VFS) | | vfs_namei | RAMFS (/) | /dev (devfs) | /proc (procfs) | /sys (sysfs) | FAT32 | ext2| +------------------------------------------------------------------------------------+ | INTER-PROCESS COMMUNICATION & ASYNC I/O ENGINE | | Anonymous Pipes | Message Queues | Shared Memory | Semaphores | io_uring Rings | +------------------------------------------------------------------------------------+ | CORE KERNEL SERVICES & SECURITY MODULE (LSM) | | Preemptive Scheduler | Task Control | POSIX Signals | Fast Syscalls | Workqueues | | High-Res Timer Wheel | Dynamic Module Loader | X.509 Keyring | POSIX Capabilities | +------------------------------------------------------------------------------------+ | NETWORK PROTOCOL STACK (L2 -> L4) & SOUND | | Ethernet L2 | ARP | IPv4 | ICMP | UDP | TCP | DHCP | DNS | BSD Sockets | | ALSA Sound Architecture | AC'97 Audio | PCM Streams | Formant TTS Synthesizer | +------------------------------------------------------------------------------------+ | MEMORY MANAGEMENT (MM) | | Physical Page Frame Allocator (PMM) | Kernel Dynamic Heap (kmalloc/kfree) | +------------------------------------------------------------------------------------+ | DEVICE DRIVER TREE & VIRT | | VGA / TTY1-4 | 16550 UART Serial | PS/2 Keyboard | PS/2 Mouse | ATA / IDE Disk | | PCI Enumerator | Intel E1000 NIC | VESA FB | CMOS RTC | ACPI Power | USB Core | +------------------------------------------------------------------------------------+ | HARDWARE ABSTRACTION LAYER (HAL) | | x86_64 Long Mode | GDT / TSS | IDT / ISRs | Dual 8259A PIC | 8254 PIT Timer | +------------------------------------------------------------------------------------+ ``` --- ## ⚡ 18-Step Master Boot Pipeline During boot, the kernel executes a deterministic 18-step master initialization sequence: | Step | Subsystem | Description | |:---:|:---|:---| | **[1/18]** | **64-Bit GDT & TSS** | Configures flat kernel/user code & data segments and Task State Segment with dedicated 64KB kernel stack. | | **[2/18]** | **IDT & ISR Table** | Populates 256-entry interrupt descriptor table with CPU exception handlers and hardware IRQ routing. | | **[3/18]** | **Dual 8259A PIC** | Remaps master (IRQ 0-7 -> 0x20-0x27) and slave (IRQ 8-15 -> 0x28-0x2F) interrupt controllers. | | **[4/18]** | **PIT & Timer Wheel** | Configures 8254 PIT channel 0 for 100 Hz (10ms resolution) driving quantum preemption & timer wheel. | | **[5/18]** | **Input & ACPI** | PS/2 Keyboard scancode decoder, PS/2 Mouse packet tracker, and ACPI power management subsystem. | | **[6/18]** | **PMM & Dynamic Heap** | 64-bit bitmap frame allocator tracking usable RAM via BIOS E820 map and 4 MB dynamic kernel heap. | | **[7/18]** | **Block Layer & ATA** | Generic Block Layer with request queues, 'noop' elevator scheduler, and 28-bit LBA ATA driver. | | **[8/18]** | **PCI, VirtIO, FB & USB** | PCI bus enumerator, VirtIO core, Linear 32-bit Framebuffer graphics, and USB host controller. | | **[9/18]** | **L2-L4 Network Stack** | Intel E1000 NIC, ARP cache, IPv4 routing, ICMP Ping, UDP, TCP state machine, DHCP & DNS. | | **[10/18]** | **Sound Architecture** | Audio core driver, AC'97 soundcard, PCM stream buffer, and Formant Text-to-Speech synthesizer. | | **[11/18]** | **Keyring & Security** | Loads X.509 trusted certificate authority keyring and enforces POSIX Capabilities Linux Security Module. | | **[12/18]** | **IPC Engine** | Anonymous Pipes, System V & POSIX Message Queues, Shared Memory segments, and Semaphore sets. | | **[13/18]** | **io_uring Subsystem** | Lockless Submission Queue Entry (SQE) & Completion Queue Entry (CQE) asynchronous I/O engine. | | **[14/18]** | **Multi-VFS Mount** | Root RAMFS, synthetic `/dev` devfs, `/proc` procfs, `/sys` sysfs, FAT32 driver, ext2 driver & initramfs. | | **[15/18]** | **Kernel Core Services** | POSIX Signal manager (32 signals), Async Workqueues, 64-bit Fast Syscalls, and Dynamic Module Loader. | | **[16/18]** | **Scheduler & LazyBox** | Starts round-robin preemptive scheduler and launches LazyBox interactive userland environment. | | **[17/18]** | **Hardware Interrupts** | Enables processor interrupts (`sti`) and transitions to userland shell. | | **[18/18]** | **Interactive Shell** | Launches multi-TTY interactive terminal console on TTY1. | --- ## 🌟 Subsystems & Codebase Architecture ```text SUB-OS/ ├── arch/x86_64/ # Long Mode bootstrap, GDT, IDT, ISRs, PIC, PIT, CPUID, Paging ├── block/ # Block Layer Core, Request Queues, Elevator I/O Schedulers ├── boot/ # Stage 1 MBR Bootloader & Stage 2 64-Bit Protected Mode Switcher ├── certs/ # X.509 ASN.1 DER Parser, Public Key Verification & Root Keyring ├── crypto/ # FIPS SHA-256, RFC 1321 MD5, IEEE 802.3 CRC32, Xorshift128+ PRNG ├── drivers/ │ ├── block/ # ATA / IDE Hard Disk PIO Driver (28-bit LBA) │ ├── char/ # VGA Text, TTY1-4 with ANSI sequences, 16550 UART Serial, PS/2 Keyboard │ ├── input/ # PS/2 Mouse Driver with packet tracking │ ├── net/ # Intel 82540EM Gigabit Ethernet NIC with DMA Descriptors │ ├── pci/ # PCI Bus Enumeration & BAR Configuration │ ├── power/ # ACPI S5 Soft-Off Power Management & Reset │ ├── rtc/ # CMOS Real-Time Clock Hardware Driver (BCD conversion) │ ├── sound/ # PC Speaker Tone Generator │ ├── usb/ # USB Host Controller Abstraction │ └── video/ # 32-bit Linear Framebuffer Graphics Engine ├── fs/ # VFS Layer, RAMFS, devfs (/dev), procfs (/proc), sysfs (/sys), FAT32, ext2 ├── include/ # Modular Subsystem Header Files ├── init/ # Early Initialization, Boot Command Line Parser, Versioning & Runlevels ├── io_uring/ # Asynchronous I/O Engine with SQE & CQE Lockless Ringbuffers ├── ipc/ # Anonymous Pipes, Message Queues, Shared Memory, Counting Semaphores ├── kernel/ # Task Scheduler, Mutexes, Signals, Syscalls, Timers, Workqueues, Modules ├── lib/ # Standard C Library (string, sprintf, bitmap, list) ├── mm/ # Physical Page Frame Allocator (PMM) & Dynamic Heap (kmalloc) ├── net/ # Ethernet, ARP, IPv4, ICMP, UDP, TCP, DHCP, DNS, BSD Sockets ├── security/ # Linux Security Modules (LSM) & POSIX Capabilities ├── sound/ # ALSA Sound Core, AC'97 Driver, PCM Audio & Text-to-Speech (TTS) Engine ├── usr/ # Embedded Initramfs Payload Tree (/etc/passwd, /etc/fstab, /usr/bin) └── userland/ # Full-Screen GNU Nano Editor & 50+ LazyBox Core Utilities ``` --- ## 📝 Full-Screen Visual Nano Editor SUB-OS includes a full-screen interactive ANSI text editor (`nano`): ```text GNU nano 2.0.0 File: /home/user/notes.txt [Modified] Hello from nano editor in SUB-OS! This is a production-level modular operating system. You can write, edit, search, and save files directly to the VFS. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ [ Wrote 148 bytes to /home/user/notes.txt ] ^G Get Help ^O WriteOut ^W Where Is ^K Cut Line ^U Paste ^X Exit ``` ### Keybindings: - **`^O` (Ctrl+O)**: WriteOut / Save file to Virtual File System. - **`^X` (Ctrl+X)**: Exit Nano and return to shell. - **`^K` (Ctrl+K)**: Cut current line to cut-buffer. - **`^U` (Ctrl+U)**: Uncut / Paste line at cursor position. - **`^G` (Ctrl+G)**: Display help cheat sheet. - **`Arrow Keys` / `Home` / `End` / `PgUp` / `PgDn`**: Smooth cursor navigation. --- ## 🧰 LazyBox Multi-Call Userland Suite (50+ Utilities) | Category | Commands Included | |---|---| | **Core** | `lazybox`, `echo`, `whoami`, `id`, `date` (CMOS RTC), `cal` | | **Filesystem & Editor** | `nano`, `ls`, `cat`, `touch`, `mkdir`, `pwd`, `cd`, `wc`, `head`, `tail`, `stat`, `cp`, `grep`, `hexdump` | | **Sound & Voice** | `tts` (Phonetic Formant Voice Synthesizer), `alsamixer` | | **Kernel & Modules** | `lsmod`, `insmod`, `rmmod` | | **Crypto & Security** | `sha256sum`, `md5sum`, `crc32`, `rand`, `certcheck`, `capsh`, `ipcs` | | **Network** | `ifconfig`, `ping`, `arp`, `dhclient`, `nslookup` | | **Storage & Devices** | `hdparm`, `lspci`, `speaker`, `mouse` | | **Virtualization & Async**| `virtinfo`, `io_uring_test` | | **System Monitoring** | `uname`, `free`, `uptime`, `dmesg`, `ps`, `top`, `sleep`, `reboot`, `poweroff` | | **Terminal** | `clear`, `neofetch`, `help` | --- ## 🚀 Building & Running ### Compilation ```bash make clean make ``` ### Emulation in QEMU ```bash qemu-system-x86_64 -drive format=raw,file=SUB-OS.img -nic model=e1000 -serial stdio -audiodev id=snd0,driver=pa -machine pcspk-audiodev=snd0 ```