How I Passed RHCSA on RHEL 10: Practical Lessons and Preparation Tips
This article is for anyone preparing for the Red Hat Certified System Administrator (RHCSA) exam.
Leadership · Java · Engineering
Building teams
and building things.
I’m Shreyas Joshi. I write about the craft of technical leadership, Java and software design, and the Linux systems that make products work.
The notebook
Ideas from the work
Adding Packages to a Yocto Image
This short, historical note shows how I added packages to a Yocto image. Recipe names and override syntax vary by Yocto release; this example is from the Warrior-era setup.For e.g, I woul...
Reading and Writing QSPI Flash with U-Boot on Zynq
This historical walkthrough records how I loaded a kernel and device tree from an SD card, wrote them to QSPI NOR flash with U-Boot, read them back for verification, and booted the kernel...
Byte Order (Endianness): Big-Endian vs Little-Endian
Endianness describes the order in which the bytes of a multi-byte value are stored in memory. It does not change the value itself; it describes how that value is represented across byte a...
Debugging Linux Device Tree Overlays on MicroZed
This historical walkthrough records how I debugged a device tree overlay for an out-of-tree PHY driver on a Yocto-built MicroZed system. Kernel, compiler, and board details affect the exa...
Booting a MicroZed Linux Root Filesystem over NFS
This walkthrough records an NFS-root setup for an Avnet MicroZed Zynq board and an Ubuntu 18.04 development VM. It is specific to that older environment and is not a current production re...
Submitting My First Linux Kernel Patch
This is all about my journey to submit my first kernel patch. Here I have discussed all the important things you must know before you submit your kernel patch and also respond to the feed...
Linux and Windows Utilities: Practical Notes, Part 1
This article collects short answers to common Linux and Windows questions. The examples reflect the tools available when these notes were written; check local versions and options before ...
Bringing Up Avnet MicroZed Linux with Yocto
This historical walkthrough records the steps I used to build U-Boot, a Linux kernel, a device tree, and a root filesystem for an Avnet MicroZed Zynq-7010 board using Yocto Warrior.Also, ...
The Chain of Responsibility Pattern in C++
The Chain of Responsibility pattern lets a request pass through a sequence of handlers. A handler can process the request or pass it to the next handler, reducing the sender’s dependency ...
The Builder Pattern in C++
The Builder pattern separates the construction of a complex object from its representation. This article uses tuner configurations to illustrate a classic builder and director arrangement.
The Observer Pattern in C++ and Qt
The Observer pattern lets a subject notify interested observers when its state changes. A subject can add or remove observers at runtime; the observers depend on the subject’s notificatio...
SOLID Principles: A Practical Guide to Object-Oriented Design
This article introduces the SOLID design principles and some of the trade-offs behind applying them.
Relationships Between Classes: Inheritance, Association and Composition
Class relationships are a foundation of object-oriented design. Two useful questions are whether one type can substitute for another (“is-a”) and whether an object collaborates with or ow...
Calling JavaScript from C++ with Qt WebKit
This article discusses on how to call a JavaScript function from C++ usingQt Framework. This framework uses Qt-Webkit. Currently, there are two waysto achieve this.
Before this notebook
Earlier projects & notes
Some older resources from my previous site are still available in their original form.