How a Single Bit Inside Your Processor Shields Your Operating System's Integrity

Comments · 825

• MA

  @manojos4114 · 1 year ago · pinned

  This video answers the exact question that I had when I first studied OS and Computer organization and architecture. <br><br>While studying OS we are told that theres something called kernel space and user space and one is more privileged than the other, but never told how this privilege is enforced. At the end of the day if both programs run on the same CPU, using the same hardware, what exactly stops a user program from invoking privileged instructions is a question that plagued me. <br><br>When I asked my professor, he answered with one word, &quot;hardware&quot; takes care of it. A very ambiguous useless answer. <br><br>Interrupts are hella underrated man, nobody talks about them. Anyway thank you for your video, It will surely help those students who had the same question I had.

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• ZU

  @Zuckerbuck · 1 year ago

  Everytime a core dumped video comes out, the world gets 20% smarter. Huge salute to you man, I love your easy to understand and lucid teaching style. Using the information from the previous videos of the ongoing video series on the workings of computers, I have finished building an ultra simple 8 bit computer. You have been like a god when it comes to my quest of learning how computers work deep down. (I&apos;m not in college yet, but I bet this is far more lucid than that)

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• PR

  @premsagar4438 · 1 year ago

  Bro, I wanna say one thing. Education system lacks the features, you&apos;re covering. Just go on. Cover everything from Digital electonics to Computer architecture &amp; organisation. I&apos;m a student &amp; you&apos;re helping a lot.

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• KA

  @KaedennYT · 1 year ago

  Professional software engineer here. I want to commend you for making this video; the topics are presented accurately, clearly, and with both honesty and integrity. You gloss over the concepts we don&apos;t need to understand (such as how interrupts are triggered from a hardware level or how program segments are loaded) and instead focus on only exactly what is needed to convey the topic.<br><br>Your definitions of &quot;kernel mode&quot; and &quot;user mode&quot; are perhaps the simplest and most accurate definitions I&apos;ve heard to date.<br><br>Thank you for using an x86-derivative assembly language in your examples. In my experience, it&apos;s the easiest to follow for new students who have not had exposure to assembly language programming.<br><br>Thank you for discussing what can go wrong when the Mode Bit is mishandled.

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• CE

  @celewign · 1 year ago

  I cannot give you enough money for these videos.

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• MI

  @MidoriMizuno · 1 year ago

  I absolutely love how you mentioned about kernel mode drivers being potentially untrustworthy (and that you&apos;re sceptical about proprietary operating systems too). I think it&apos;s very important to help people realise that.

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• SO

  @SomeYoutube-bl6my · 1 year ago

  I literally started writing my own kernel like 1 month ago as part of my mastery at 42. Would have been way harder to understand what I actually have to do without your videos starting at how stack heap works until now with this video!<br><br>Massive respect being able to explain SO complex topics so that they are easy to understand - shows crazy mastery of the subject.<br>Keep up the amazing work!

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• AK

  @akramhany-6403 · 1 year ago (edited)

  A year ago, I was doing a car&apos;s racing game project with my colleges in assembly x86, and we encountered a problem where we wanted to make taking the input of keyboard kind of asynchronous, where you can press more than one button at the same time and all of them get handled at the same time, the problem was that the interrupt that was used to handle getting the pressed key on the keyboard didn&apos;t actually handle this the way we wanted, so after investigating a lot we had to override the default handler routine and used another one that did what we wanted, and this was actually one of the coolest things I have ever done since I started learning programming

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• DR

  @drbadzer · 1 year ago

  The way you explain OS concepts is above the level of most courses in even the most prestigious universities. Please never stop making these 🙏🏽

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• SC

  @scoffpickle9655 · 1 year ago (edited)

  Dont show this video to bit-flipping solar particles<br>(For the love of god this is a joke stop correcting me over a funny mario 64 reference)

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• DU

  @duelbrosgames · 1 year ago

  I learned more about OS in this video than my entire bachelors degree in computer science. What a well explained and visually clear video!

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• SE

  @seid44 · 1 year ago

  what a generational run bro, been here since (almost) the start and praying to stay for long. <br>i bet this is what it felt like for earlier generations to watch and study from 3b1b and Ben Eater at the time they were releasing their videos.<br><br>i&apos;ve recently started going the book route, going through the computer systems book, and i have to say you are such a good (and even on par) supplement.<br>i can&apos;t wait for the virtual memory video. cheers bro

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