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2025

Routour🗼: Building the Ultimate Travel Router

6 minute read

Published:

Recently I finished the project Routour🗼, a powerful travel router that is compact yet supports many features with components including Raspberry Pi CM4, Intel BE200 WiFi card, DeskPi Mini Cube, and RaspAP with Debian. In this post, I am documenting the entire process since I believe this would help someone in the future. This includes the hardware modifications and software configurations needed to achieve a feature-rich yet portable network router.

CrPT🔑: Lattice Problem

4 minute read

Published:

Welcome to the second episode of the CrPT🔑 series. In this episode, I discuss lattices and how they are connected to cryptography. As we discussed in the introduction episode, since quantum computers are expected to break many current asymmetric algorithms, lattice-based methods have attracted growing interest as a promising post-quantum alternative. Lattice-based cryptography relies on the hardness of solving lattice problems, let’s look at the fundamental idea behind them.

CrPT🔑: Applications of Cryptography

8 minute read

Published:

Welcome to my new blog series CrPT🔑 that discuss about applications of cryptography. In this first episode, I will explore current trends in cryptography and their impact on various applications. With significant developments in Artificial Intelligence (AI) and recent breakthroughs in quantum computing, it is a great time to discuss the future of cryptography. This episode aims to examine the factors that will and will not influence the future of applications that rely on cryptography.

2024

Android Device Security and GSI: A Layman’s Guide

5 minute read

Published:

Android devices come with several security components that work together to protect your device and personal data. Here’s a simple explanation of who makes these components, their security implications, and how they collaborate to keep your device (data) safe.

TinyOS🐞: Interrupts and Peripherals

9 minute read

Published:

A computer needs to communicate with the external world to perform tasks. To facilitate this, we have peripheral hardware. When these peripherals need to talk to the operating system, we have interrupts. In this episode of TinyOS🐞 tutorial series, we will be looking at interrupts and how to use them.

TinyOS🐞: Spinlocks

8 minute read

Published:

In this episode of episode of the TinyOS🐞 tutorial series, we will be looking at how to protect critical sections in processes using spinlocks.

TinyOS🐞: Preemptive Scheduling

9 minute read

Published:

In the MultiTasking episode of the TinyOS🐞 tutorial series, we implemented “Cooperative Multitasking”. Next in TimerInterrupt episode, we discussed how the RISC-V time interrupt mechanism works. If you have missed them, I highly recommend going through them before proceeding.

2023

TinyOS🐞: TimerInterrupts

11 minute read

Published:

In the previous episode MultiTasking, we implemented a operating system with cooperative multitasking. However, without the implementation of an interruption mechanism, our system cannot support preemptive multitasking.

TinyOS🐞: Multitasking

5 minute read

Published:

In the previous episode ContextSwitch of TinyOS🐞, we introduced the context switching mechanism under the RISC-V architecture. In this episode we will be looking at Multitasking in our DIY operating system.

Docker for Research🐳

5 minute read

Published:

Lots of researchers have been curious about my Docker setups. Docker is actually a super handy tool for research. So, in this article, I’ll walk you through the basics of Docker for engineers/researchers.

TinyOS🐞: Context-Switch

5 minute read

Published:

In the previous episode HelloWorld of TinyOS🐞, we discussed how to print strings to the UART serial port for a specific processor on QEMU that utilises RISC-V architecture. This episode takes us further into the operating system territory, introducing the concept of “Context-Switching”.

TinyOS🐞: HelloWorld

9 minute read

Published:

Welcome to the first and simplest episode of TinyOS🐞. In this episode we will be looking at memory map settings of QEMU and writing a simple HelloWorld program. If you missed the introduction article about TinyOS🐞, you can find it here.

TinyOS🐞: Operating System Tutorial

1 minute read

Published:

TinyOS🐞 is a tutorial series about minimal operating system kernel implementation based on the comprehensive tutorial series mini-risscv-os. This operating system kernel is based on RISC-V instruction set architecture. Credits goes to the original authors of mini-risscv-os. A fully built environment is available as a docker environment. This tutorial will cover several chapters related to implementing a operating system from begining.

Verification of Systems Code

12 minute read

Published:

Previously we looked at the verification of Verilog hardware implementations. In this post, we will be looking at the verification of firmware or systems code. Here the hardware implementation is abstracted with Instruction Level Abstraction (ILA). This allows us to make complex verification problems more tractable.

Veri(fy)log : Verifying Hardware with Rosette

6 minute read

Published:

In previous post, we discussed Racket and Rosette. This is the post where we are going to verify our hardware designs using the infrastructure we have developed so far. In a nutshell, we will be looking at verifying Verilog hardware designs with Rosette.

Rosette101

15 minute read

Published:

This post is focusing on the verification with Rosette. Rosette defines extensions on Racket programming language to uplift the process of verification of implementations. We introduced Racket basics in the previous post. To make things more interesting we have used Jupyter Notebook environment. This time we will be using Rosette in the same environment, which will make verification problems much more interactive and fun.

Racket101

7 minute read

Published:

In this post, we will be looking at basic Racket programming. At the end of the post, we will be doing some Racket programming exercises on the Jyputer environment. If you missed the previous post, where we looked at setting up the environment for the RackeTutes tutorial series, you can check it out from here.

Racket with Jupyter

1 minute read

Published:

RackeTutes is a tutorial series for Racket and Rosette solver-aided programming language to promote “Secure and validated” hardware designs.

Future of Computing Giants

5 minute read

Published:

This article is based on a talk conducted by Professor Jack Dongarra, who is a world renowned expert in numerical computing and tools for parallel computing and also the Turing Award winner in the year 2021.

Bootloader at Home?

6 minute read

Published:

So far we looked at implementing firmware for bare metal use cases. But you may have seen that in most of the hardware SDK’s, they suggest using a bootloader to load your programs.

Linker Scripts in Brief

6 minute read

Published:

In this episode of the firmware tutorial, let us build a firmware linker script from scratch for picoRV processor. You may remember in the previous tutorials we have used sections.lds to get the elf file. This linker file contains information about how much memory is available in our system and where and where specific hardware components use the memory so that the compiler can place different functions appropriately.

Hello World! Firmware

5 minute read

Published:

In the previous article, we looked at the different steps involved in the process of compiling firmware that is ready to run on actual hardware. For that, we have used the default firmware given in the picoRV repo. In this article, we write a very simple program from scratch to print “HELLO WORLD” to the UART output of the picoRV processor.

Firmware at Bare metal

5 minute read

Published:

In this tutorial, we are going to look at writing firmware for an embedded hardware device. This tutorial is solely focused on simulations. However, it can be synthesized to work on FPGAs.

2019

Neural Network on 8-bits?

2 minute read

Published:

XOR neural network is one of the basic and simplest neural networks. It is trained by XOR gate input as input features and XOR gate output as the prediction. A basic XOR gate can be created using 3 layers neural network. The architecture that I have used and how I inferred it on FPGA is discussed here onwards.

Learn from Failures

6 minute read

Published:

This article is about two incidents that happened in the past, creating catastrophic tragedies due to mistakes in simple lines of code. Incidents like this signify the importance of verification of the systems that we build.