Development

November 10, 2020 was in many ways a landmark event in the microprocessor industry: Apple unveiled its new Mac Mini, the main feature of which was the new M1 chip, developed in-house. It is not an exaggeration to say that this processor is a landmark achievement for the ARM ecosystem: finally an ARM architecture chip whose performance surpassed x86 architecture chips from competitors such as Intel, a niche that had been dominated for decades.

But the main interest for us is not the M1 processor itself, but the Rosetta 2 binary translation technology. This allows the user to run legacy x86 software that has not been migrated to the ARM architecture. Apple has a lot of experience in developing binary translation solutions and is a recognized leader in this area. The first version of the Rosetta binary translator appeared in 2006 were it aided Apple in the transition from PowerPC to x86 architecture. Although this time platforms were different from those of 2006, it was obvious that all the experience that Apple engineers had accumulated over the years, was not lost, but used to develop the next version - Rosetta 2.

We were keen to compare this new solution from Apple, a similar product Huawei ExaGear (with its lineage from Eltechs ExaGear) developed by our team. At the same time, we evaluated the performance of binary translation from x86 to Arm provided by Microsoft (part of MS Windows 10 for Arm devices) on the Huawei MateBook E laptop. At present, these are the only other x86 to Arm binary translation solution that we are aware of on the open market.

Introduction

For the last five years, there have virtually been almost no global-scale application-layer attacks.

During this period, the industry has learned how to cope with the high bandwidth network layer attacks, including amplification-based ones. It does not mean that botnets are now harmless.

End of June 2021, Qrator Labs started to see signs of a new assaulting force on the Internet – a botnet of a new kind. That is a joint research we conducted together with Yandex to elaborate on the specifics of the DDoS attacks enabler emerging in almost real-time.

In April 2021 Microsoft announced a new version of its IDE – Visual Studio 2022 – while also announcing that the IDE would be 64-bit. We've been waiting for this for so long – no more 4 GB memory limitations! However, as it turned out, it's not all that simple...

If you are strongly interested in MISRA and would like to understand whether your project meets one of the MISRA association's standards, there is a solution. It's name is MISRA Compliance. PVS-Studio has recently learned how to generate the MISRA Compliance report. This article describes how you can use this feature. This can make somebody's life better.

Knowing parameters of small-signal control-to-output transfer functions makes it easier for engineers to design compensation networks of DC/DC converters. The equations for SEPIC can be found in different works and Application Notes, but there are differences. A work has been done to solve this problem.

Simplified design equations for SEPIC with Current Mode control (CM) in Continuous Conduction Mode (CCM) suitable for practical design of compensation networks are shown.

With this API implementing two factor authentication (2FA) is easier than ever. Just in 5 minutes I’ll guide you how to generate and validate time-based one-time passwords (TOTP) for second factor authentication (2FA) in fast and secure manner.

Hello!

This post is about writing a fast enumerator in C#:

foreach (var i in 1..10)

We will figure out whether it's possible to make it as fast as for, and what can we do to improve our performance.

A lot of benchmarks and sharplab coming. Let's rock!

• We’ll find out what is an in-memory database, or IMDB. When and how are they better than disk solutions?
• Then, we’ll consider their architecture. What about their efficiency, reliability, and scaling?
• Then, we’ll delve into technical details. Data types, iterators, indexes, transactions, programming languages, replication, and connectors.

On August 25th, 2021, the Linux kernel celebrated its 30th anniversary. Since then, it's changed a lot. We changed too. Nowadays, the Linux kernel is a huge project used by millions. We checked the kernel 5 years ago. So, we can't miss this event and want to look at the code of this epic project again.

XSS - or cross-site scripting - is one of the most common vulnerabilities in web applications. It has been on the OWASP Top 10 list (the list of the most critical security risks to web applications) for a while now. So let's figure out together how your browser can acquire and execute a script from a third-party website, and what this may lead to (spoiler: your cookies could get stolen, for example). And while we're at it, we'll talk about ways you can protect yourself from XSS.

In my project, I was faced with the need to implement a scroll bar. The standard approaches didn't fully satisfy what designers wanted to see. Here is an example, it is slightly different in appearance from what I needed, but the essence is approximately the same: the scroll bar should be on the right side of the list and take into account the padding of the scroll bar, with the slider displaying the percentage of the scrolled part of the list.

It seems that the problem of calculating the absolute value of a number is completely trivial. If the number is negative, change the sign. Otherwise, just leave it as it is. In Java, it may look something like this:

public static double abs(double value) {
  if (value < 0) {
    return -value;
  }
  return value;
}

It seems to be too easy even for a junior interview question. Are there any pitfalls here?

So, I finally found a moment to write a bit about how we created the water for TReload. Our basic goal was to flood all of the levels with acid - a lot of acid, as the flooded area is massive :) Here’s one of the results which we got out of this process:

With the .NET5 release further development of some projects was questionable due to the complexity of porting. One can abandon small outdated libraries or find a replacement. But it's hard to throw away Microsoft.Office.Interop.Word.dll. Microsoft doesn't plan to add compatibility with .NET Core/5+, so in this article we focus on creating Word files with Open XML SDK.

In this video, we will look at how to connect brushless motor controllers to a Linux computer. Specifically, we will use a computer running Debian. The same steps would work for Ubuntu Linux and other Linux distributions derived from Debian.

I've got a small sensorless brushless motor, and a bigger brushless motor with a built-in absolute encoder. Lets look at how to control those from my Debian Linux computer. Servosila brushless motor controllers come in several form factors with either a circular or a rectangular shape. The controllers come with a set of connectors for motors and encoders as well as for USB or CANbus networks.

The controllers can be powered by a power supply unit or by a battery. To spice up my setup, I am going to use a battery to power the controllers and thus their motors. The controllers need 7 to 60 volts DC of voltage input. If I connect the battery, the controllers get powered up. The small LED lights tells us that the controllers are happy with the power supply.

We need to connect the brushless motor controllers to the Linux computer. There are two ways to do that - via CANbus or via USB. Lets look at the USB option first. A regular USB cable is used. Only one of the controllers needs to be connected to a computer or a PLC.

Next, we need to build an internal CANbus network between the controllers. We are going to use a CANbus cross-cable to interconnect the controllers. Each controller comes with two identical CANbus ports that help chain multiple controllers together in a network. If one of the interconnected brushless motor controllers is connected to a computer via USB, then that particular controller becomes a USB-to-CANbus gateway for the rest of the network. Up to 16 controllers can be connected this way via a single USB cable to the same control computer or a PLC. The limit is due to finite throughput of the USB interface.

Thanks for your feedbacks

I thank the members of the Habr community for their benevolent attitude to the article by the author «Speed Dating with the CodeIgniter 4 on GitHub» in the form of votes and comments.

The friendly attitude to the author prompted him to continue developing a topic dedicated to PHPUnit as part of CodeIgniter 4.

Install Xdebug on XAMPP (Windows 32-bit (x86))

1. Why Xdebug? In file «appstarter/tests/README.md» in the «Requirements» section explicitly states: «You also need to install XDebug to successfully calculate code coverage».

PHP is widely known as an interpreted programming language used mainly for website development. However, few people know that PHP also has a compiler to .NET – PeachPie. But how well is it made? Will the static analyzer be able to find actual bugs in this compiler? Let's find out!

In this video, we will look at how to connect brushless motors to a Windows computer via USB. We are going to connect a network of Servosila brushless motor controllers to the computer. The other option is CANbus interface, but we will look at CANbus in a dedicated video. A regular USB cable is used. Note that the USB cable is not used to power the controller and its motor.

The first brushless motor controller in network appears to Windows as a Virtual COM port. Once connected via USB, it can be found in a general list of devices in the Window's "Settings" window. Up to 16 controllers can be connected this way via a single USB cable to the same control computer or a PLC. If one of the interconnected brushless motor controllers is connected to a computer via USB, then that particular controller becomes a USB-to-CANbus gateway for the rest of the network.

If your computer happens to have more that one serial port, you may wish to check a COM port's number assigned by Windows to the controller. Then, you pick this COM port in a drop down menu in the Servoscope software, and click Connect. If the COM port is not listed in the drop-down menu, click the Refresh button. If everything is good, the controller appears in a list of devices. Double-click to open up a control and configuration window.

Protocol AXI4 was developed for High-bandwidth and low latency applications. It is designed to allow communication between master and slave devices. Master is typically a DMA or CPU and slaves are DRAM controllers, or other specific protocol controllers: UART, SPI, and others. Sometimes one component can implement multiple instances of this protocol. Usually, a prefix is used to differentiate between multiple AXI4 interfaces.

For example, Ethernet MAC can integrate DMA and slave interface used to command MAC. MAC can accept commands on the slave interface that contain data about the location of the next ethernet packet and MAC can start fetching this packet using the separate master interface instance.

This article was motivated by common design mistakes AXI4 designers make when they are designing their Digital IP. (Looking at you Xilinx)