One Man, Two Kernels, and a Lot of RISC-V

Yuri Zaporozhets, the mind behind QRV Systems, is an exceptionally prolific developer. His portfolio is a whirlwind of low-level engineering, ranging from custom RISC-V hardware to FPGA-based mainframes and the complete reimagining of legacy operating systems.

The FOSS community has recently taken notice of his latest venture, an OS dubbed QSOE. However, to understand the genesis of QSOE, one must look at the trail of ambitious projects that led him here.

Disclosure: Zaporozhets openly acknowledges that he utilizes Anthropic's Claude LLM to assist in his development process.

🖥️ The GateMate Personal Computer

Toward the end of 2025, Zaporozhets unveiled the GateMate PC. While it feels like a high-end IBM PC-compatible from the late 1980s, its heart is modern: a 25 MHz RISC-V core.

Inspiration and Specs

The project was a nostalgic nod to the first computer Zaporozhets ever encountered in 1992—the IBM PS/2 Model 30. While the original Model 30 was somewhat underwhelming, the GateMate is designed to easily outperform the later Model 30-286.

Feature	GateMate PC Specification
CPU	RISC-V core (based on Stefan Nolting's `NeoRV32`)
Clock Speed	$25 \text{ MHz}$
Video	Custom controller; 80x30 text in "Hi-Color"
Memory	8 KB ROM (BIOS) + 8 MB PSRAM via QSPI
Hardware	Olimex GateMate A1-EVB FPGA
Cost	$\approx €50$ ( $\approx \$ 57 / £42$)
OS	`GMDOS` (currently in early development)

The project was a journey of incremental wins, documented via his blog—starting from the arrival of the board, moving to the implementation of the PLL, and finally achieving video output.

🏛️ The GateMate System/359

Using the same Olimex FPGA board, Zaporozhets created the System/359, a miniature mainframe. It is important to note that this is ~~a clone~~ a tribute to the IBM System/360 series.

Architectural Nuances

While it captures the spirit of the S/360, it introduces modern changes:

Endianness: The S/359 is little-endian, whereas the S/390 is big-endian.
Philosophy: It is "inspired by, not compatible with" the original.

Zaporozhets leveraged his history as a NASM contributor (1999–2004), specifically his work on RDOFF2. Although RDOFF2 was excised from NASM 3.0, it lives on within his asm359 project.

Current Progress Checklist:

Working assembler with NASM macroprocessor
Simple IPL execution
Channel I/O controller functionality
PSRAM module completion $\rightarrow$ Next step: SYS1.NUCLEUS

⚙️ The QNX Evolution: From Port to QRV

Zaporozhets' fascination with microkernels led him to QNX, a system revered for its architecture. His journey began with an attempt to port QNX 6.4 to RISC-V for his FU740 workstation.

The Technical Hurdle

The original QNX 6.4 source (mirrored on GitHub) was a 32-bit ILP32 codebase targeting architectures like x86 and ARM. Zaporozhets undertook the massive task of transitioning this to a 64-bit LP64 system.

A humanoid robot with a stethoscope stands before glowing hexagon graphics.

After a five-year hiatus, the project evolved from a simple port into a ground-up rewrite called the QRV Operating System.

Key distinctions of QRV:

It is not a patch of QNX; it is a reworking.
It simplifies the original codebase.
It targets RISC-V 64-bit specifically.

Project Timeline

March: First publication of the QRV OS.
April: Version v0.27 achieves a successful boot to a multi-user login.
May: Version 0.43 is released, marking the conclusion of the project.

Two clenched fists collide in a dramatic illustration with sparks and a dark background.

The goal was to explore the requirements of bringing a clean microkernel to modern hardware, a mission he considers complete with the release of version 0.43.

// Conceptual representation of the QRV transition
#define OLD_QNX_MODE ILP32 // 32-bit
#define QRV_MODE LP64     // 64-bit RISC-V