SUB-OS: Modular Monolithic Linux-Compatible Operating System

   _____ _    _ ____          ____   _____ 
  / ____| |  | |  _ \        / __ \ / ____|
 | (___ | |  | | |_) |______| |  | | (___  
  \___ \| |  | |  _ <|______| |  | |\___ \ 
  ____) | |__| | |_) |      | |__| |____) |
 |_____/ \____/|____/        \____/|_____/ 

SUB-OS is a multi-architecture, production-grade modular monolithic operating system kernel engineered in C and Assembly. Built for high performance, modularity, and Unix/Linux compatibility, SUB-OS supports 64-bit x86 (x86_64), 64-bit ARM (aarch64), and 32-bit ARM (armv8i / AArch32) targets.

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🌟 Key Architecture & Capabilities

• 🎯 Multi-Architecture HAL:
  • x86_64 (AMD64 / Intel 64): Custom 2-stage MBR bootloader, E820 BIOS memory mapping, 4-level PML4 48-bit paging, GDT, 256-entry IDT, 8259 PIC, 8254 PIT timer.
  • aarch64 (ARMv8-A 64-Bit): Exception levels (EL1), 16-entry vector table, ARM Generic Interrupt Controller (GICv2), ARM Generic Arch Timer (100 Hz), Stage-1 39-bit VA MMU, PL011 UART.
  • armv8i (ARM32 / AArch32): Banked exception mode stacks (IRQ, ABT, UND, SVC), VMSAv7 1MB Section MMU, GICv2 distributor, CP15 Generic Timer, VFP/NEON FPU, PL011 UART.
• 🎛️ Linux-Style Kconfig TUI Configurator (make configure):
  • Full interactive lxdialog GUI interface (Royal Blue backdrop, floating modal windows, drop shadows, and menu hierarchy).
  • Dynamic Kbuild-style selective compilation based on .config and include/config/autoconf.h.
• 📁 Storage & Filesystem Layer:
  • FAT32 (VFAT) storage driver with directory traversal and /mnt/fat32 auto-mounting.
  • Second Extended (EXT2) Linux filesystem driver.
  • Virtual File System (VFS): POSIX open, read, write, close, seek, mount interface.
  • Synthetic DevFS (/dev), ProcFS (/proc), and Sysfs KObject Hierarchy (/sys).
  • Dynamic in-memory RAM disk (/dev/ram0).
• 🖧 Hardware Device Drivers:
  • Storage Controllers: NVMe PCIe SSD, AHCI SATA 6Gb/s, IDE/ATA Hard Disks, VirtIO-Block.
  • Network Adapters: Intel 82540EM Gigabit Ethernet, Realtek RTL8139 Fast Ethernet, VirtIO-Net 10GbE.
  • Multimedia & Display: Bochs/VBE dynamic resolution video adapter, 2D TrueColor Canvas Rasterizer, Intel High Definition Audio (Azalia HDA), AC'97 sound codec, Formant TTS synthesizer, 8-Bit Melody player.
  • Bus & Sensors: PCI bus enumerator, USB 3.0 Extensible Host Controller (xHCI), HWMON CPU temperature and fan tachometer sensors, VirtIO-RNG hardware entropy generator, Unix98 PTY subsystem.
• 🌐 Networking, Firewalls & Daemons:
  • Full L2–L4 IPv4 protocol stack with dynamic ARP, ICMP Echo (ping), UDP, and full 3-way handshake TCP state machine.
  • NetFilter stateful packet inspection firewall (iptables).
  • Built-in OpenSSH 2.0 Daemon (sshd) on port 2222.
  • Built-in Micro HTTP REST API Server (httpd) on port 8080.
• 🔒 Kernel Security & Async Engine:
  • Linux Security Module (LSM) enforcing POSIX capabilities and DAC.
  • X.509 Cryptographic Keyring with signature verification.
  • In-Kernel eBPF Register Virtual Machine and verifier.
  • io_uring lockless asynchronous Submission/Completion ring buffers.
  • Preemptive multi-tasking scheduler with Round-Robin quantum and spinlock synchronization.
  • Systemd-style unit manager (systemctl), cron background scheduler (crond), and RFC 5424 Syslog engine.
• 🧰 LazyBox Userland Suite (70+ Linux Applets):
  • Interactive shell with history, tab autocompletion, ANSI cursor editing, and script runner (sh).
  • GNU-compatible Nano visual text editor.
  • Full utilities: ls, cat, touch, mkdir, rm, cp, pwd, cd, grep, wc, head, tail, stat, df, mkfs.vfat, hexdump, neofetch, uname, free, uptime, top, ps, dmesg, netstat, ifconfig, ping, curl, ssh, tts, alsamixer, sensors, lsdev, lsmod, and more.

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🏛️ Comprehensive Architecture

+------------------------------------------------------------------------------------+
|                             USERLAND & SYSTEM SUITE                                |
|  Interactive Shell | GNU Nano | Script Runner (sh) | LazyBox Suite (70+ Tools)     |
|  Micro HTTP Server | SSH 2.0 Daemon | Service Manager (systemctl) | Syslog Engine  |
+------------------------------------------------------------------------------------+
|                         VIRTUAL FILE SYSTEM LAYER (VFS)                            |
|  vfs_namei | RAMFS (/) | /dev (devfs) | /proc (procfs) | /sys (sysfs) | FAT32 | ext2|
+------------------------------------------------------------------------------------+
|         NAMESPACES, INTER-PROCESS COMMUNICATION & ASYNC I/O ENGINE                 |
|  PID/UTS Isolation | Pipes | Message Queues | Shared Memory | Semaphores | io_uring|
+------------------------------------------------------------------------------------+
|                   CORE KERNEL SERVICES, SECURITY & TRACING                         |
|  Preemptive Scheduler | Fast Syscalls | Dynamic Modules | eBPF Virtual Machine     |
|  LSM POSIX Capabilities | X.509 Keyring | Workqueues | Telemetry & Kernel Tracer   |
+------------------------------------------------------------------------------------+
|               NETWORKING, NETFILTER FIREWALL & SOUND ARCHITECTURE                  |
|  Ethernet | ARP | IPv4 | ICMP | UDP | TCP | DHCP | DNS | Sockets | NetFilter FW   |
|  Embedded HTTP Server (8080) | SSH Server (2222) | Intel HDA | AC'97 | Formant TTS |
+------------------------------------------------------------------------------------+
|                             DEVICE DRIVER TREE                                     |
|  NVMe PCIe SSD | AHCI SATA | ATA IDE | VirtIO-Blk | Ramdisk (/dev/ram0)            |
|  Intel E1000 NIC | RTL8139 NIC | VirtIO-Net | USB 3.0 xHCI | HWMON Sensors         |
|  Bochs VBE Display | 2D Canvas | VGA / TTY1-4 | 16550 Serial | PL011 UART          |
+------------------------------------------------------------------------------------+
|                        HARDWARE ABSTRACTION LAYER (HAL)                            |
|  x86_64 (AMD64/PML4) | aarch64 (ARMv8-A/GICv2/MMU) | armv8i (AArch32/Section MMU)  |
+------------------------------------------------------------------------------------+

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🚀 Quick Start Guide

1. Prerequisites

Install the standard build essentials and cross-compilers:

# Ubuntu / Debian
sudo apt update
sudo apt install build-essential nasm qemu-system-x86 qemu-system-arm \
                 gcc-aarch64-linux-gnu binutils-aarch64-linux-gnu \
                 gcc-arm-linux-gnueabihf binutils-arm-linux-gnueabihf \
                 dialog python3

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2. Linux-Style TUI Configuration

Launch the interactive Kconfig configurator:

make configure

(Also available via make menuconfig)

Fast Architecture Presets:

make x86_64_defconfig    # Configure for x86_64 (Intel / AMD 64-Bit)
make aarch64_defconfig   # Configure for 64-bit ARM (Cortex-A57)
make armv8i_defconfig    # Configure for 32-bit ARM (Cortex-A15)

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3. Compilation & Live Emulation

Target: x86_64 (Default)

make x86_64_defconfig
make
make run

Port forwardings automatically configured in QEMU:

• SSH Server: ssh root@localhost -p 2222 (Password: root)
• HTTP REST API: http://localhost:8080/api/status

Target: aarch64 (ARMv8-A 64-Bit)

make aarch64_defconfig
make ARCH=aarch64
make run ARCH=aarch64

Target: armv8i (ARM32 / AArch32)

make armv8i_defconfig
make ARCH=armv8i
make run ARCH=armv8i

Graphical Window Emulation (Optional SDL/GTK GUI)

make run-gui

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🧰 LazyBox Command Matrix (70+ Utilities)

Category	Commands Included
Core & Shell	lazybox, sh, echo, env, export, whoami, id, date, cal
Filesystem & Edit	nano, ls, cat, touch, mkdir, rm, cp, pwd, cd, wc, head, tail, stat, df, mkfs.vfat, grep, hexdump
Networking & Servers	ifconfig, ping, arp, dhclient, nslookup, netstat, iptables, httpd, sshd, curl, wget, ssh
Hardware & Devices	lspci, lsdev, lsblk, hdparm, sensors, speaker, mouse, alsamixer, tts, virtinfo
Security & SysAdmin	su, passwd, useradd, certcheck, capsh, ipcs, logger, logread, systemctl, service, crontab
Kernel & Tracing	lsmod, insmod, rmmod, slabinfo, trace, unshare, io_uring_test
Diagnostics & Metrics	neofetch, uname, free, uptime, top, htop, ps, dmesg, vmstat, iostat, calc, matrix
System Control	clear, help, sleep, reboot, shutdown, poweroff, tty

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📦 Official Release

Download precompiled kernel binaries and bootable disk images from GitHub: 👉 SUB-OS v0.0.1-beta Release

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📄 License

SUB-OS is distributed under the open-source MIT License. See LICENSE for details.