Chapter 10 — Timer-Driven Preemptive Multitasking

This entry is part 10 of 35 in the series Writing A Linux Style Operating System From Scratch

In Chapter 9, we built cooperative multitasking: That works, but it has a major weakness: A thread like that can monopolize the CPU forever. This chapter adds the next step: timer-driven preemption. With preemptive scheduling: OSDev describes preemptive multitasking as scheduling where an interrupt, usually timer-driven, allows the kernel to take control away from the

Chapter 41 — Dynamic /programs from the Program Registry

This entry is part 4 of 4 in the series AI for Software Development

Chapter 40 closed the loop on shell-visible background jobs by giving them local %N references. That matters here because it gave us a stable chapter boundary:the shell can now be scripted without hardcoding fragile PIDs, so the filesystem work that follows can focus on the namespace itself instead of fighting the test harness. The next

Chapter 7 — A Real Virtual Memory Mapping Layer

Chapter 7 — A Real Virtual Memory Mapping Layer
This entry is part 7 of 35 in the series Writing A Linux Style Operating System From Scratch

In Chapter 5 we enabled paging, but only with a fixed identity map: In Chapter 6 we built a heap, but it still had an important weakness: because only the first 16 MiB were identity-mapped. Now we fix the architectural problem. This chapter adds a small virtual memory manager, or VMM: This lets the kernel

Chapter 5 — Turning On Paging

Chapter 5 — Turning On Paging
This entry is part 5 of 35 in the series Writing A Linux Style Operating System From Scratch

In Chapter 4, we built the first memory-management layer: Now we add the next layer: paging. Paging lets the CPU translate a virtual address into a physical address through page tables. In 32-bit x86 paging without PAE, a virtual address is split into a page-directory index, page-table index, and page offset; page directories and page

Writing a Linux-style Operating System From Scratch

Writing a Linux-style Operating System From Scratch
This entry is part 1 of 35 in the series Writing A Linux Style Operating System From Scratch

Today, we are beginning a new article series: “Writing a Linux-Style Operating System From Scratch.” In this series, we will walk step by step through the process of creating our own operating system from the ground up. Many operating system tutorials stop shortly after the system boots and prints a simple message on the screen.

Building the i686-elf-gcc Cross-Compiler

Together, these tools allow us to assemble, compile, link, inspect, and transform kernel binaries without using the host operating system’s normal compiler target.

The Pirate Software Paradox: What Happens When Influence Outpaces Skill

The Pirate Software Paradox: What Happens When Influence Outpaces Skill
pirate

There’s a real disconnect between the code that’s visible and the veteran status that’s claimed. This discrepancy isn’t trivial

The Case Against 3rd Party APIs

The Case Against 3rd Party APIs
Broken Chain image

Call me a control freak. But after decades in software development, I’ve learned to be cautious, especially when it comes to building systems on top of third-party APIs. While APIs can offer short-term acceleration, they often introduce long-term fragility that you can’t control. Why Relying on 3rd Party APIs Is Risky Using third-party APIs might

Why GAMBAS BASIC Deserves a Place in Your Development Toolbox

One of GAMBAS’s biggest advantages is its fully integrated development environment (IDE), which resembles VB6 and offers an easy-to-use graphical interface. This makes creating forms, handling events, and connecting to databases significantly faster than using more complex frameworks.

Developing an Open Hardware Device Programmer

This entry is part 1 of 1 in the series Open Universal Device Programmer

Introduction As an electronics enthusiast with over 50 years of experience, I’ve had the privilege of witnessing the dramatic evolution of computing systems. From the early days of 4 and 8-bit machines with minimal RAM to today’s powerful 64-bit computers with terabytes of storage, the progress has been nothing short of extraordinary. The same transformative