Hard Disks and File Systems Part 2

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Hey, everybody, welcome back to the course. So in the last video, we talked about kind of the foundational structure of the hard disco H d D the hard disk drive. We also talked about what SST or solid state drive stood for.

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In this video, we're gonna talk about

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bit, bite and nibble along with some other topics as well.

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So just the things you want to know between bit by Nebel. If you're not familiar on and that is not a nibble, by the way in the photo, that's trouble. But if you're familiar Star Trek, that's just a neat little photo to see

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so bit. So basically, this is our foundational thing, right? That's our binary digit, that zero, that one. Essentially, that turning on or turning off right for the electricity component of it. We either have electricity on or electricity off,

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and then we have our bite, which is eight bits and then also are nibble, which is forbid so half of Ah by.

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So keep those in mind for your actual examination. Just in case you see anything about that,

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the next thing we're gonna talk about is a bios parameter block or BPB Um basically, this describes the physical layout of the storage volume so you'll see it in things Windows based. You'll see it in things like fat 16 fat, 32 on and then NT f s as well,

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good or globally unique. Identify WR.

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I just know that this is 128 bits on. Then it's used. Basically, this is identifying information, right? So these can be generated. They're identifying some component of the system.

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GPT, you're the good partition table basically provides a layout of the action petition table so you'll see this in like HT T h d d ah, hard disk drive or SST or solid state drives.

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I've been just mentioning here of the header ihsaa Logical Block address one. So just keep that in mind for examination as well

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Yueh fei or unified extensible firmware interface. So this is pretty much what we're seeing now. Days as bios is being phased out or if it's not already phased out. Um,

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so basically, this defines a software interface between the actual operating system and the firmware. That's what are kind of our graphic there shows it's an intermediary type of thing.

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This also so vote supports remote diagnostics as well. So, again, some features that bios doesn't have,

02:23

so you you e f I boot process faces. So, um, you just wanna kinda memorize these for the actual examination itself. So we've got the security phase pretty if I initialization driver, execution, environment, boot device, election and run time. So we're gonna talk about each one of these a little bit

02:43

security phase or SEC handles the platform, restart events. It also creates a temporary memory. It starts isn't rooted trust as well, which is pretty easy to remember. If you remember the component of security phase right on, then of course, it passes off any required handoff information over to the P I, which is the next stage.

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So the p e r the pre e If I initialization phase, this one's going to initialize permanent memory andan. Also, it's gonna describe that memory inside of H O B l's or handoff blocks.

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It's gonna describe the firm where volume location as well. And then, of course, it passes it all along to the next level.

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So the DX year driver is execution environment, so this one basically contains a DXC dispatcher, which discovers and executes the DXC drivers, make sure they're actually rooted in the correct order

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and also terminates at successful operating system boot eso. Once everything comes up, it's Ah, it's good to go.

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And then, of course, you know the drivers are going to initialize the processor in the chip said, and then also the platform components as well.

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The brute device selection phase for BDS. That's where we see the platform boo policy. It also initialize is consuls. It's gonna load the device drivers as well as the boot selections and then also execute them

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runtime. So this enables the operating system to read or write different environmental variables. It also said towards updates of firmware. And then and then the main thing you want to remember is that it clears you e f I from memory.

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So just a quick post assessment question here. So we talked about Neville earlier. So the question here a nebulous six bits Is that true or false?

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All right, you're correct. If you guessed false, right? So if you remember, a nibble is half of a bite, so that's four bits. So a bite. It's Abe. It's the nibbles has half of that, it's gonna be four bits

04:41

are. So in this video, we just talked about bit by bite and nibble and talked about how we can differentiate between those. We also talked about you e f i as well as your e f i boot phases.

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So the next video we're gonna start jumping into our actual file systems so on before that will actually jump into our move processes. So we'll talk about Windows Mac as well as linens. Now, we're not gonna take a deep dive into the root process because you don't need to know that for the actually I actual exam. But I've listed out a few steps and we'll talk about

05:13

that kind of walking through