SUB-OS: 64-Bit Production Modular Monolithic Operating System

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

SUB-OS is an open-source, production-grade 64-bit modular monolithic operating system engineered from the ground up for the x86_64 architecture. Designed for both cloud/bare-metal servers and interactive workstation use, SUB-OS features a lightweight, high-performance modular kernel without unnecessary bloat.

It comes fully equipped with a bare-metal driver tree, SLAB Object Allocator, an advanced virtual file system (VFS) with FAT32, ext2, sysfs, and devfs, Lightweight Process & Container Namespaces, Kernel Event Tracing (FTrace ringbuffers), Stateful Packet Inspection (NetFilter Firewall), an Embedded Micro HTTP Web Server & REST API (httpd), Systemd-style Service Unit Manager (systemctl), RFC 5424 Syslog Telemetry, Cron Background Job Scheduler, Multi-User SHA-256 Authentication (su, passwd, useradd), Ramdisk (/dev/ram0), a full L2-L4 networking protocol stack with BSD Sockets, 8-Bit Retro Melody Synth & Formant Text-to-Speech (TTS) voice synthesizer, AC'97 sound architecture, full-screen visual nano editor, and the LazyBox multi-call userland environment with 65+ Linux-compatible utilities and shell scripting (sh).

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🏛️ Comprehensive System Architecture

+------------------------------------------------------------------------------------+
|                             USERLAND & SYSTEM SUITE                                |
|  Interactive Shell | GNU Nano 2.0.0 | Script Runner (sh) | LazyBox (65+ Tools)     |
|  Micro HTTP Server | Service Manager (systemctl) | Syslog Reader | Multi-User Auth |
+------------------------------------------------------------------------------------+
|                         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 | Anonymous Pipes | Message Queues | SHM | Semaphores | io_uring|
+------------------------------------------------------------------------------------+
|                   CORE KERNEL SERVICES, SECURITY & TRACING                         |
|  Preemptive Scheduler | Task Control | POSIX Signals | Fast Syscalls | Workqueues  |
|  High-Res Timer Wheel | Dynamic Module Loader | Kernel Event Tracer | LSM Security  |
|  System Metrics Telemetry | Cron Scheduler Daemon | RFC 5424 Kernel Syslog Engine  |
+------------------------------------------------------------------------------------+
|               NETWORKING, NETFILTER FIREWALL & SOUND ARCHITECTURE                  |
|  Ethernet L2 | ARP | IPv4 | ICMP | UDP | TCP | DHCP | DNS | Sockets | NetFilter FW |
|  Embedded HTTP Server & REST API | AC'97 Audio | Formant TTS | 8-Bit Melody Engine |
+------------------------------------------------------------------------------------+
|                             MEMORY MANAGEMENT (MM)                                 |
|     Physical Page Allocator (PMM)  |  Dynamic Heap  |  SLAB / SLUB Object Cache    |
+------------------------------------------------------------------------------------+
|                             DEVICE DRIVER TREE & VIRT                              |
|   VGA / TTY1-4 | 16550 UART Serial | PS/2 Keyboard | PS/2 Mouse | ATA Hard Disk    |
|   PCI Enumerator | Intel E1000 NIC | Ramdisk (/dev/ram0) | VESA FB | CMOS RTC      |
+------------------------------------------------------------------------------------+
|                        HARDWARE ABSTRACTION LAYER (HAL)                            |
|   x86_64 Long Mode | GDT / TSS | IDT / ISRs | Dual 8259A PIC | 8254 PIT Timer      |
+------------------------------------------------------------------------------------+

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⚡ 18-Step Master Boot Pipeline

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, Heap & SLAB	64-bit bitmap frame allocator, 4 MB kernel heap, and high-performance SLAB object cache layer.
[7/18]	Block Layer, Ramdisk & ATA	Generic Block Layer with request queues, Ramdisk (/dev/ram0), 'noop' elevator, and 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 & NetFilter	Intel E1000 NIC, NetFilter stateful firewall, ARP, IPv4 routing, ICMP Ping, UDP, TCP, DHCP, DNS & HTTPD.
[10/18]	Sound & Melody Synth	Audio core driver, AC'97 soundcard, 8-Bit Melody player, and Formant Text-to-Speech synthesizer.
[11/18]	Keyring, Auth & Namespaces	Loads X.509 trusted keyring, SHA-256 Shadow Authentication, POSIX Capabilities LSM, and namespaces.
[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]	Services, Syslog & Telemetry	Starts RFC 5424 Syslog daemon, Telemetry Metrics, Cron scheduler, and Systemd Service Unit Manager.
[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 with dynamic CWD prompt.

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🧰 LazyBox Multi-Call Userland Suite (65+ Utilities)

Category	Commands Included
Core & Scripting	lazybox, sh (Script runner), echo, env, export, whoami, id, date (CMOS RTC), cal
Filesystem & Editor	nano, ls, cat, touch, mkdir, pwd, cd, wc, head, tail, stat, cp, grep, hexdump, basename, dirname
Server & Web	httpd (Micro Web Server), curl, wget, systemctl / service (Daemon Manager), crontab
Security & Logging	logger, logread (Syslog viewer), su, passwd, useradd, certcheck, capsh, ipcs
Sound & Voice	tts (Phonetic Formant Voice Synthesizer), tune (8-Bit Melody Player), alsamixer
Kernel & Tracing	lsmod, insmod, rmmod, slabinfo, trace, unshare (Namespace containers)
Crypto & Hashes	sha256sum, md5sum, crc32, rand
Network & Firewall	ifconfig, ping, arp, dhclient, nslookup, iptables (Stateful Firewall), netstat
Storage & Devices	hdparm, lspci, speaker, mouse
Virtualization & Async	virtinfo, io_uring_test
Monitoring & Telemetry	uname, free, uptime, vmstat, iostat, htop, top, dmesg, ps, sleep, reboot, poweroff
Terminal	clear, neofetch, help

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🌐 Server Operations Demonstration

1. Launching Micro HTTP Server & Testing REST API

sub-os:/> httpd start 80
HTTPD: Web Server listening on 0.0.0.0:80 (HTTP/1.1)

sub-os:/> curl /api/status
HTTP/1.1 200 OK
Server: SUB-OS/0.2.0 (x86_64)
Content-Type: application/json
Content-Length: 159
Connection: close

{"os":"SUB-OS","version":"0.2.0-lts (x86_64)","arch":"x86_64","uptime_sec":1,"mem_total_kb":130944,"mem_free_kb":122752,"requests_served":1,"status":"HEALTHY"}

2. Managing System Services

sub-os:/> systemctl
  UNIT                       LOAD   ACTIVE SUB     DESCRIPTION
  syslogd.service            loaded active running System Logging Daemon
  networking.service         loaded active running IPv4 Network Interface Manager
  httpd.service              loaded active running Embedded Micro HTTP Web Server
  crond.service              loaded active running Periodic Command Scheduler Daemon
  firewall.service           loaded active running NetFilter Stateful Packet Inspection

3. Multi-User Authentication & Switching

sub-os:/> whoami
root

sub-os:/> su admin
Switched to user 'admin'

sub-os:/> whoami
admin

sub-os:/> id
uid=1000(admin) gid=1000(admin) groups=1000(admin)

sub-os:/> su root
Switched to user 'root'

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🚀 Building & Running

Compilation

make clean
make

Emulation in QEMU

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