mirror of
https://github.com/subhobhai943/SUB-OS.git
synced 2026-10-26 00:52:50 +00:00
203 lines
12 KiB
Markdown
203 lines
12 KiB
Markdown
# SUB-OS: 64-Bit Production Modular Monolithic Operating System
|
||
|
||
```text
|
||
_____ _ _ ____ ____ _____
|
||
/ ____| | | | _ \ / __ \ / ____|
|
||
| (___ | | | | |_) |______| | | | (___
|
||
\___ \| | | | _ <|______| | | |\___ \
|
||
____) | |__| | |_) | | |__| |____) |
|
||
|_____/ \____/|____/ \____/|_____/
|
||
```
|
||
|
||
[]()
|
||
[]()
|
||
[-purple.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. It is built adhering to the internal design principles of modern UNIX/Linux kernels, featuring full bare-metal hardware drivers, physical and dynamic memory management, a virtual file system (VFS), networking protocol stack, cryptographic engine, Linux Security Modules (LSM), asynchronous `io_uring` ringbuffers, hypervisor detection, full-screen visual `nano` editor, and the **LazyBox** multi-call userland environment.
|
||
|
||
---
|
||
|
||
## 🏛️ System Architecture
|
||
|
||
```text
|
||
+-------------------------------------------------------------------------+
|
||
| USERLAND & SYSTEM SUITE |
|
||
| Interactive Shell | GNU Nano 2.0.0 | LazyBox Suite (ls, cat, ping, ...) |
|
||
+-------------------------------------------------------------------------+
|
||
| VIRTUAL FILE SYSTEM (VFS) |
|
||
| vfs_namei | Root RAMFS | /dev (devfs) | /proc (procfs) | initramfs |
|
||
+-------------------------------------------------------------------------+
|
||
| ASYNC I/O ENGINE & SECURITY FRAMEWORK |
|
||
| io_uring (SQE/CQE Rings) | Linux Security Modules (LSM) | Keyring |
|
||
+-------------------------------------------------------------------------+
|
||
| CORE SERVICES & CRYPTO ENGINE |
|
||
| Preemptive Scheduler | Task Control | SHA-256 | MD5 | CRC32 | PRNG |
|
||
+-------------------------------------------------------------------------+
|
||
| MEMORY MANAGEMENT (MM) |
|
||
| Physical Page Frame Allocator (PMM) | Kernel Heap (kmalloc/kfree) |
|
||
+-------------------------------------------------------------------------+
|
||
| DEVICE DRIVER TREE & VIRT |
|
||
| VGA / TTY1-4 | 16550 UART Serial | PS/2 Keyboard | ATA / IDE Disk |
|
||
| PCI Enumerator | Intel E1000 NIC | VirtIO Core | PC Speaker |
|
||
+-------------------------------------------------------------------------+
|
||
| HARDWARE ABSTRACTION LAYER (HAL) |
|
||
| x86_64 Long Mode | GDT / TSS | IDT / ISRs | Dual 8259A PIC | 8254 PIT |
|
||
+-------------------------------------------------------------------------+
|
||
```
|
||
|
||
---
|
||
|
||
## ⚡ 14-Step Master Boot Pipeline
|
||
|
||
During boot, the kernel executes a deterministic 14-step master initialization sequence:
|
||
|
||
| Step | Subsystem | Description |
|
||
|:---:|:---|:---|
|
||
| **[1/14]** | **64-Bit GDT & TSS** | Configures flat kernel/user code & data segments and Task State Segment with dedicated 64KB kernel stack. |
|
||
| **[2/14]** | **IDT & ISR Table** | Populates 256-entry interrupt descriptor table with CPU exception handlers and hardware IRQ routing. |
|
||
| **[3/14]** | **Dual 8259A PIC** | Remaps master (IRQ 0-7 -> 0x20-0x27) and slave (IRQ 8-15 -> 0x28-0x2F) interrupt controllers. |
|
||
| **[4/14]** | **8254 PIT Timer** | Configures channel 0 for 100 Hz (10ms resolution) driving quantum preemption. |
|
||
| **[5/14]** | **PS/2 Keyboard** | Full scancode translation table with circular ringbuffer, Shift, CapsLock, Ctrl keys, and multi-TTY switching. |
|
||
| **[6/14]** | **Physical Memory Manager** | 64-bit bitmap frame allocator tracking usable RAM via BIOS E820 map (31,712 free 4KB pages). |
|
||
| **[7/14]** | **Kernel Dynamic Heap** | Boundary-tag dynamic heap allocator with 4 MB initial pool, coalescing, and reallocation. |
|
||
| **[8/14]** | **ATA / IDE Storage** | 28-bit LBA PIO hard disk controller supporting sector read/write operations on primary master. |
|
||
| **[9/14]** | **PCI, VirtIO & Net** | PCI bus enumerator, VirtIO core, and Intel 82540EM Gigabit NIC with circular DMA RX/TX descriptors. |
|
||
| **[10/14]** | **Security & Keyring** | Loads X.509 trusted certificate authority keyring and enforces POSIX Capabilities Linux Security Module (LSM). |
|
||
| **[11/14]** | **io_uring Subsystem** | Lockless Submission Queue Entry (SQE) & Completion Queue Entry (CQE) asynchronous I/O engine. |
|
||
| **[12/14]** | **Virtual File System** | Mounts root in-memory RAMFS, synthetic `/dev` devfs, `/proc` procfs, and unpacks embedded initramfs tree. |
|
||
| **[13/14]** | **Scheduler & LazyBox** | Starts round-robin preemptive scheduler and launches LazyBox interactive userland environment. |
|
||
| **[14/14]** | **Hardware Interrupts** | Enables processor interrupts (`sti`) and transitions to userland shell. |
|
||
|
||
---
|
||
|
||
## 🌟 Subsystems & Linux Directory Structure
|
||
|
||
### 1. Bootloader & Kernel Core (`arch/x86_64/`, `kernel/`)
|
||
- **Two-Stage Custom MBR Bootloader**:
|
||
- `boot/boot.asm`: 512-byte MBR sector loaded at `0x7C00` that loads Stage 2 using BIOS INT 13h extensions.
|
||
- `boot/stage2.asm`: Enables A20 line, queries E820 memory map, builds 4-level PML4 identity paging tables (4GB address space), transitions through 32-bit Protected Mode into 64-bit Long Mode, and loads kernel in 64-sector chunks.
|
||
- **Preemptive Multi-Tasking**: Process Control Blocks (PCB), round-robin task scheduler driven by timer ticks, atomic spinlocks, and semaphores.
|
||
- **Kernel Logging & Serial Diagnostics**: ANSI color `printk()` supporting loglevels (`KERN_INFO`, `KERN_WARN`, `KERN_ERR`), a 64KB kernel `dmesg` ring buffer, and simultaneous output to COM1 serial port.
|
||
|
||
### 2. Early Initialization & Versioning (`init/`)
|
||
- `init/cmdline.c`: Kernel command line parsing (`root=`, `console=`, `init=`, `quiet`, etc.) and system runlevel management (`RUNLEVEL_SINGLE`, `RUNLEVEL_MULTIUSER`, `RUNLEVEL_GRAPHICAL`).
|
||
- `init/version.c`: Version metadata and banner formatting.
|
||
|
||
### 3. X.509 Cryptographic Keyring (`certs/`)
|
||
- `certs/x509.c`: ASN.1 DER parser for X.509 v3 public key certificates (Subject, Issuer, Validity, SHA-256 Fingerprint, RSA/ECDSA trust validation).
|
||
- System trusted keyring supporting kernel module and executable signature verification.
|
||
|
||
### 4. Asynchronous I/O Engine (`io_uring/`)
|
||
- `io_uring/io_uring.c`: High-performance non-blocking asynchronous I/O ringbuffers with SQE (Submission Queue Entries) and CQE (Completion Queue Entries) for concurrent disk and network I/O.
|
||
|
||
### 5. Linux Security Modules & Capabilities (`security/`)
|
||
- `security/lsm.c`: Hookable security infrastructure with DAC and MAC permission callbacks.
|
||
- `security/capability.c`: POSIX Capabilities model (`CAP_CHOWN`, `CAP_DAC_OVERRIDE`, `CAP_NET_RAW`, `CAP_SYS_ADMIN`, etc.).
|
||
|
||
### 6. Userspace Initramfs & Payload (`usr/`)
|
||
- `usr/initramfs.c`: Populates filesystem tree (`/usr/bin`, `/var/log`, `/etc/passwd`, `/etc/issue`, `/etc/fstab`).
|
||
|
||
### 7. Virtualization & VirtIO Subsystem (`virt/`)
|
||
- `virt/hypervisor.c`: Hypervisor detection via CPUID leaves (QEMU, KVM, VMware, VirtualBox, Hyper-V).
|
||
- `virt/virtio.c`: VirtIO core device driver registration and split virtqueue framework.
|
||
|
||
### 8. Memory Management Subsystem (`mm/`)
|
||
- **Physical Memory Manager (`pmm.c`)**: Page frame allocator managing physical RAM using a high-efficiency bitmap.
|
||
- **Kernel Dynamic Heap (`kmalloc.c`)**: Provides `kmalloc`, `kzalloc`, `kcalloc`, `krealloc`, and `kfree` with boundary tag headers and adjacent block coalescing.
|
||
|
||
### 9. Virtual File System (`fs/`)
|
||
- **Unified VFS Core (`vfs.c`)**: Posix-like file operations (`open`, `read`, `write`, `close`, `lseek`, `mkdir`, `create`) with hierarchical path resolution (`vfs_namei`) and support for up to 64 file descriptors.
|
||
- **Root RAMFS (`ramfs.c`)**: Dynamic in-memory directory and file tree with auto-expanding data buffers.
|
||
- **Synthetic Device Filesystem (`devfs.c`)**: Mounted at `/dev`, providing `/dev/null`, `/dev/zero`, `/dev/random`, `/dev/urandom`, and `/dev/tty`.
|
||
- **Process Metrics Filesystem (`procfs.c`)**: Mounted at `/proc`, generating dynamic metrics (`/proc/version`, `/proc/meminfo`, `/proc/cpuinfo`, `/proc/uptime`, `/proc/net/dev`).
|
||
|
||
### 10. Hardware Drivers (`drivers/`)
|
||
- **VGA & TTY (`vga.c`, `tty.c`)**: 80x25 text mode driver with 4 Virtual Consoles (TTY1-4 switched via `Alt+F1`–`Alt+F4`) and full ANSI escape sequence parsing.
|
||
- **Serial Port (`serial.c`)**: 16550 UART COM1 driver at 115200 baud.
|
||
- **PS/2 Keyboard (`keyboard.c`)**: Interrupt-driven scancode decoder with modifier state machine and full Ctrl+key combination mapping.
|
||
- **ATA / IDE Disk (`ata.c`)**: 28-bit LBA PIO disk controller.
|
||
- **PCI Bus (`pci.c`)**: Enumeration and Base Address Register (BAR) configuration.
|
||
- **Intel E1000 Gigabit NIC (`e1000.c`)**: Intel 82540EM Gigabit NIC driver with hardware DMA ringbuffers.
|
||
- **PC Speaker (`speaker.c`)**: Programmable timer channel 2 tone generator.
|
||
|
||
### 11. Cryptography Engine (`crypto/`)
|
||
- **SHA-256 (`sha256.c`)**: FIPS 180-4 compliant 256-bit cryptographic digest.
|
||
- **MD5 (`md5.c`)**: RFC 1321 compliant 128-bit hash function.
|
||
- **CRC32 (`crc32.c`)**: IEEE 802.3 standard cyclic redundancy check.
|
||
- **PRNG (`prng.c`)**: Xorshift128+ cryptographic pseudo-random number generator.
|
||
|
||
---
|
||
|
||
## 📝 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
|
||
|
||
SUB-OS ships with an extensive multi-call userland binary suite (`lazybox`):
|
||
|
||
| Category | Commands |
|
||
|---|---|
|
||
| **Core** | `lazybox`, `echo`, `whoami`, `id`, `date`, `cal` |
|
||
| **Filesystem & Editor** | `nano`, `ls`, `cat`, `touch`, `mkdir`, `pwd`, `cd`, `wc`, `head`, `tail`, `stat`, `cp`, `grep`, `hexdump` |
|
||
| **Crypto & Security** | `sha256sum`, `md5sum`, `crc32`, `rand`, `certcheck`, `capsh` |
|
||
| **Network** | `ifconfig`, `ping`, `arp` |
|
||
| **Storage & Devices** | `hdparm`, `lspci`, `speaker` |
|
||
| **Virtualization** | `virtinfo`, `io_uring_test` |
|
||
| **System Monitoring** | `uname`, `free`, `uptime`, `dmesg`, `ps`, `top`, `sleep`, `reboot`, `poweroff` |
|
||
| **Terminal** | `clear`, `neofetch`, `help` |
|
||
|
||
---
|
||
|
||
## 🚀 Building & Running
|
||
|
||
### Prerequisites
|
||
- `gcc` (with `-ffreestanding`, `-fno-pie`, `-mcmodel=kernel`) or `x86_64-elf-gcc`
|
||
- `nasm` (Netwide Assembler)
|
||
- `qemu-system-x86_64` (for hardware virtualization)
|
||
|
||
### Compilation
|
||
```bash
|
||
make clean
|
||
make
|
||
```
|
||
|
||
### Emulation in QEMU
|
||
```bash
|
||
# Run with Intel Gigabit NIC, ATA drive, PC Speaker, and Serial Console
|
||
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
|
||
```
|