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MyOS v1.2.0

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@arshc0der arshc0der released this 19 Oct 02:13
v1.2.0
e9ca50e

MyOS v1.2.0 - Hardware Information, Scrollback and Command History

MyOS v1.2.0 turns the shell into a much more useful tool. The kernel can now read the boot information from GRUB, identify the CPU, list PCI devices and read the clock. The console gains a working cursor and scrollback, and the shell gains command history.

MyOS is a minimal 32-bit x86 hobby operating system written in C and assembly.

What's New

System and Hardware Information

  • meminfo: shows lower and upper memory, where the kernel is loaded, and the full memory map reported by GRUB, with the total usable RAM.
  • cpuinfo: shows the CPU vendor and model name, family/model/stepping, supported features (SSE, AVX, and others), and whether MyOS is running inside a virtual machine.
  • lspci: scans the PCI bus and lists devices such as network, storage and graphics controllers, with vendor and device IDs.
  • sysinfo: a one-screen summary of the OS, CPU, memory, bootloader, PCI device count and virtualization.
  • date: now reads the real date and time from the RTC clock instead of reporting that it is unavailable.

Console

  • Working cursor: the blinking hardware cursor now follows the text as you type. It is hidden while you are scrolled back.
  • Scrollback: the console keeps 275 lines of history. Use PgUp and PgDn to scroll, and Home and End to jump to the oldest and newest output. A [ SCROLLBACK -N ] label shows while you are looking at old output, and typing returns you to the live screen.
  • Colors: headings, labels, the prompt and error messages are now colored.
  • Better backspace: backspace now works correctly across a line that wraps onto the next row.

Shell and Keyboard

  • Command history: press Up and Down to recall previous commands. The new history command lists them (the last 16 are kept).
  • More keys supported: arrow keys, Page Up/Down, Home, End and Delete are now decoded, and Caps Lock works.
  • reboot: now restarts the computer through the keyboard controller instead of printing a not-implemented message.
  • Updated help: lists every command and the navigation keys.

Build System

  • make iso builds the bootable ISO and make run builds it and starts QEMU. The GRUB tool is detected automatically (grub2-mkrescue or grub-mkrescue).
  • The kernel version is now consistently reported as 1.2.0 by version and about.

Command Reference

Command Description
help List available commands
about About MyOS
version Show the kernel version
sysinfo System summary
meminfo Memory size, kernel location and memory map
cpuinfo CPU vendor, model, features and virtualization
lspci List PCI devices
date Date and time from the RTC clock
history Commands typed so far
echo <text> Print text to the screen
clear Clear the screen and scrollback
reboot Restart the computer
halt / shutdown Halt the CPU

Keyboard Shortcuts

Key Action
Up / Down Recall previous commands
PgUp / PgDn Scroll the screen up or down
Home / End Jump to the oldest or newest output
Backspace Delete the previous character

Known Limitations

  • Memory management: the memory map is read and displayed, but there is no page allocator, heap or virtual memory manager yet.
  • Line editing: the Left and Right arrow keys do not move inside the command line yet. Use Backspace to correct mistakes.
  • Clock: date shows the RTC time, which is usually UTC (in a virtual machine it follows the host clock). There is no timezone support.
  • PCI names: lspci recognizes only common vendors and device classes. Others are shown as "Unknown vendor" or "Other device".
  • Scrollback size: 275 lines. clear also erases the scrollback.
  • Panic handler: kernel_panic exists but is not yet called automatically by other kernel components.
  • Interrupts: the keyboard is still read by polling. Interrupt-driven input is planned.

Downloads

File Description
myos-1.2.0.iso Bootable ISO image
myos-1.2.0-source.zip Complete source code, with build instructions in the README
SHA256SUMS.txt SHA-256 checksums to verify the downloads

Quick Start

QEMU

qemu-system-i386 -cdrom myos-1.2.0.iso -m 128M

Once it boots, try sysinfo, meminfo, cpuinfo and lspci.

VirtualBox / VMware: create a 32-bit Other/Unknown virtual machine with at least 64 MB of RAM and no virtual hard disk, attach myos-1.2.0.iso as the optical drive, and start the virtual machine.

Real hardware: write the ISO image to a USB drive or CD and boot in BIOS / legacy mode.

Note: always take care when writing images to physical drives. Selecting the wrong device can erase existing data.

Verify Your Download

sha256sum -c SHA256SUMS.txt

Build from Source

Extract myos-1.2.0-source.zip and open a terminal in the project directory.

# Build the kernel
make clean
make

# Build the bootable ISO
make iso

# Build and run in QEMU
make run

If you prefer the manual steps:

cp kernel.elf iso/boot/kernel.elf
grub2-mkrescue -o myos.iso iso        # or: grub-mkrescue -o myos.iso iso
qemu-system-i386 -cdrom myos.iso -m 128M

Build requirements: GCC with 32-bit compilation support, GNU Make, GRUB utilities, xorriso and QEMU.

Fedora:

sudo dnf install gcc glibc-devel.i686 make qemu-system-x86 grub2-tools grub2-tools-extra xorriso

Debian / Ubuntu:

sudo apt install build-essential gcc-multilib grub-pc-bin xorriso mtools qemu-system-x86

Upgrading from v1.1.0

No changes to the boot process are needed. v1.2.0 adds new source files (multiboot.c, cpu.c, pci.c, rtc.c and keys.h) and updates boot.S, kernel.c, console.c, keyboard.c, shell.c, linker.ld and the Makefile. Replace your project with the v1.2.0 source archive and rebuild with make clean && make.

Full Changelog

MyOS v1.1.0 to v1.2.0 changelog

License

MyOS is released under the MIT License.

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