Speaker 1: Ever wonder what's really going on inside your iPhone or Mac. Today,
Speaker 1: we're going deep, really deep into Apple's operating systems, and
Speaker 1: our guide for this little adventure is Jonathan Levin's OS
Speaker 1: Internals Volume one. Right, this book, it's pretty dense, it is, Yeah,
Speaker 1: but don't worry. We're here to break it down. Whether
Speaker 1: you're like a hardcore tech enthusiast or just curious about
Speaker 1: what makes your Apple devices tick. We're going to unpack
Speaker 1: it all for you.
Speaker 2: Absolutely. Yeah. We're going beyond that sleek interface and that
Speaker 2: user friendly design, right, We're going to the core, the
Speaker 2: backbone of it all, okay, which is called Darwin.
Speaker 1: Darwin is that like some kind of secret code name
Speaker 1: for Apple's OS?
Speaker 2: Not really, no, okay. Darwin is the open source, UNIX
Speaker 2: based foundation of Apple's operating systems. Ah. Okay, so think
Speaker 2: of it as the engine under the hood.
Speaker 1: Okay. So what's so special about Darwin being you and
Speaker 1: IX based.
Speaker 2: Well, for one thing, yeah, it means that your I
Speaker 2: phone actually shares a lineage oh wow, with powerful server systems,
Speaker 2: like big server systems. Yes, and it has this very robust,
Speaker 2: well tested core okay. And Darwin's actually one of the
Speaker 2: last few UNX certified operating systems, which puts it in
Speaker 2: the same league as Lennux and Solaris.
Speaker 1: Oh so you're saying that, like my phone is running
Speaker 1: on the same fundamental system as like supercomputer. Kind of Yeah,
Speaker 1: that's pretty wild.
Speaker 2: It is. And this UNANAX heritage that we're talking about,
Speaker 2: it has some really real world implications. Okay, it makes
Speaker 2: Apple devices incredibly stable. Think about how rarely, if ever
Speaker 2: your iPhone crashes. True, and it means it can handle
Speaker 2: some really demanding tasks, yeah, very smoothly. Plus it makes
Speaker 2: it a lot easier for developers who are already familiar
Speaker 2: with UNANX to work with Apple systems.
Speaker 1: Makes sense.
Speaker 2: So it's not just this cool family tree. It actually
Speaker 2: affects the performance and the development of your Apple device.
Speaker 1: I see. So it's not just about like a cool lineage.
Speaker 1: It's actually impacting like the performance and development of Apple devices.
Speaker 1: Yeah that's interesting. Yeah, so but how did Darwin like
Speaker 1: come to be? What's the story there?
Speaker 2: Well, it's a fascinating story okay, that actually involves Steve
Speaker 2: Jobs and this company called next Ta Okay, and to
Speaker 2: think about it, imagine a branching tree Okay. The trunk
Speaker 2: of that tree is Next t Step, got it. This
Speaker 2: was the operating system okay, developed by Steve Jobs's company
Speaker 2: Next to You back in the late eighties, right, And
Speaker 2: when Apple acquired Next Tea in nineteen ninety six, they
Speaker 2: brought Next T Step along with them. Yeah, and that
Speaker 2: became the foundation for Darwin.
Speaker 1: Oh. So, Garwin is like the seed that blossomed into
Speaker 1: like the entire Apple os ecosystem that we know today exactly,
Speaker 1: mac os iOS, wachos, and they all share this common
Speaker 1: ancestor exactly, and.
Speaker 2: Each branch of that tree has evolved these unique characteristics
Speaker 2: for its very specific device.
Speaker 1: That makes me wonder though, if they're all built on
Speaker 1: the same base, Like how much can developers actually share
Speaker 1: and reuse across those different Apple devices? Like could I
Speaker 1: theoretically write an app that would work seamlessly on my
Speaker 1: iPhone and Mymac.
Speaker 2: That's a great question. Yeah, and it kind of gets
Speaker 2: at the heart of how Apple balances consistency and flexibility
Speaker 2: across its ecosystem. Okay, but before we get into app development, sure,
Speaker 2: I think it's important to understand how Apple structures its
Speaker 2: operating system. Okay, the architecture, so quick, got it.
Speaker 1: So let's unpack the architecture then. Sure is it as
Speaker 1: sleek and minimalist as the design of their devices.
Speaker 2: Well, Apple presents a very simple, five layered model. Okay,
Speaker 2: So you have the application layer, which is what you
Speaker 2: directly interact with, right. Then there's the Application Frameworks layer,
Speaker 2: which provides tools and libraries for developers.
Speaker 1: Got it.
Speaker 2: Below that is the core Services layer, which handles system
Speaker 2: level tasks. And finally you have the kernel and Device
Speaker 2: writer's layer, which is what interacts with the hard one.
Speaker 1: So everything's really neatly organized, each layer with its specific role.
Speaker 2: Very Apple on paper. Yes, it's clean, it's elegant, but
Speaker 2: the reality, as with most things, is a little bit
Speaker 2: more complex. Okay, if we look deeper, we're going to
Speaker 2: find a much more intricate, messier architecture.
Speaker 1: MESSI you're telling me there's hidden complexity beneath Apple's famously
Speaker 1: polished surface. I knew it. It couldn't be that simple.
Speaker 2: Like take the runtime environment for example. Okay, it's technically
Speaker 2: part of the core Services layer, but it actually spans
Speaker 2: multiple layers, blurring those very clean lines we saw before,
Speaker 2: and this complexity actually becomes even more apparent when you
Speaker 2: compare the architectures of mac os and iOS.
Speaker 1: Oh interesting.
Speaker 2: They share some similarities, of course, but there are these
Speaker 2: distinct differences as well, Yeah, which were the unique needs
Speaker 2: and constraints of each platform.
Speaker 1: So it's more like a carefully choreographed dance than like
Speaker 1: a rigid hierarchy.
Speaker 2: Apple wants to maintain a consistent user experience, I get
Speaker 2: it right, but it also needs to provide the power
Speaker 2: and flexibility that's required for all these different applications and
Speaker 2: hardware exactly. That's a tough balancing act, it.
Speaker 1: Is, and understanding this tension between user friendliness and capability
Speaker 1: helps us really appreciate how Apple makes these design choices
Speaker 1: that you, as a user experience every day. But to
Speaker 1: really grasp the inner workings of the OS, we need
Speaker 1: to go even deeper to the heart of what's called
Speaker 1: the kernel environment.
Speaker 2: Okay, this is called X and U X and U.
Speaker 2: What is that is that like the Apple version of a.
Speaker 1: Kernel, Well, the kernel is the core of an operating system.
Speaker 1: It's responsible for managing the system's resources and inner acting
Speaker 1: directly with the hardware. Xn U is particularly interesting because
Speaker 1: it's a hybrid kernel that combines elements of a microkernel
Speaker 1: called MOCK with components from.
Speaker 2: BSDON, another UNAX derivative.
Speaker 1: Okay, I'm losing you a bit microkernel BSD. What are
Speaker 1: we talking about here?
Speaker 2: Think about it this way. MOCK is this tiny, highly
Speaker 2: flexible kernel that was originally designed to be incredibly adaptable. Okay,
Speaker 2: it could even run on top of other kernels.
Speaker 1: Wow.
Speaker 2: Now, BSc, on the other hand, is known for its robustness,
Speaker 2: its stability, and its performance.
Speaker 1: So they kind of took the best of both worlds exactly.
Speaker 1: So X and U is like a hybrid car. Yes,
Speaker 1: it combines like the fuel efficiency of a microkernel with
Speaker 1: the power and reliability of a more traditional kernel.
Speaker 2: That's a really great way to put it. Actually, And
Speaker 2: this hybrid approach that we're talking about, yeah, it allows
Speaker 2: out to really achieve that balance between flexibility and performance,
Speaker 2: got it, which is critical for a modern operating system.
Speaker 1: This is all fascinating stuff, but I'm starting to wonder, like, Yeah,
Speaker 1: why should I, as like a regular user, care about
Speaker 1: all these technical details about kernels and architectures. What's like
Speaker 1: the takeaway for me?
Speaker 2: Well, understanding how the OS works under the hood can
Speaker 2: actually enhance your user experience. They Okay, it helps you
Speaker 2: appreciate why your Apple devices are so responsive, why they
Speaker 2: rarely crash, and why they can handle a wide range
Speaker 2: of tasks.
Speaker 1: Okay.
Speaker 2: It also gives you this deeper understanding of the decisions
Speaker 2: that Apple makes about app management, security, overall system design.
Speaker 1: Interesting. So it's not just about like geeking out over
Speaker 1: the technical specs. It's about understanding the forces you're shaping
Speaker 1: our digital experiences. I like that.
Speaker 2: And speaking of shaping experiences, let's move on to another
Speaker 2: crucial aspect of Apple's OS. Ok and that's the file system.
Speaker 1: The filesystem. Okay.
Speaker 2: Now you might think of this as just storage space, right,
Speaker 2: but it's actually so much more than that. Okay. It's
Speaker 2: this carefully structured system that has a very profound impact
Speaker 2: on how your device functions.
Speaker 1: Gotcha, Okay, I'm intrigued. How does apples approach to file
Speaker 1: systems differ from say, Windows or Android.
Speaker 2: One key difference is how Apple partitions it's filesystems. Okay,
Speaker 2: they separate the system partition from the data partition.
Speaker 1: Wait, so there are separate sections for the operating system
Speaker 1: itself and my personal files? Exactly Why is that important?
Speaker 2: Well, the separation is actually quite clever.
Speaker 1: Okay.
Speaker 2: This is what allows for those very seamless system updates
Speaker 2: that Apple's known for.
Speaker 1: So that's why I can update my iPhone and not
Speaker 1: have to worry about losing all my photos and messages
Speaker 1: exactly because the system is getting updated on one partition
Speaker 1: and my data is safe on the other one.
Speaker 2: Exactly.
Speaker 1: Thought about it that way. That's actually a really elegant solution.
Speaker 2: Yeah, it is. And speaking of elegant solutions, let's talk
Speaker 2: about Apple's discimages. Those dot DMG files.
Speaker 1: Yeah, dot dmg files.
Speaker 2: You encounter them all the time when you're downloading software.
Speaker 1: I usually just like click through them without really giving
Speaker 1: them much thought. Yeah, special about them.
Speaker 2: What's fascinating about them, Yeah, is that dot dmg files
Speaker 2: are not merely archives like dot zip files. They are,
Speaker 2: in essence, mini file.
Speaker 1: System mini filesystems. You mean, like a tiny, self contained
Speaker 1: drive inside.
Speaker 2: Of a file. Precisely, you can mount a dot dmg
Speaker 2: file and explore it just like you would any other
Speaker 2: drive on your system.
Speaker 1: That's pretty cool. But why go through the trouble of
Speaker 1: creating a custom image format like this? Why not just
Speaker 1: use like standard archives.
Speaker 2: That's a good question. It could be about security, okay,
Speaker 2: ensuring that the software hasn't been tampered with. It could
Speaker 2: also be about maintaining that consistent user experience, giving Apple
Speaker 2: more control over how the software is presented and installed.
Speaker 1: So there's more two dot dmg files than meets the eye.
Speaker 1: It's another example of how Apple's design choices, even like
Speaker 1: these seemingly small ones, really reflect their overall philosophy of
Speaker 1: control and user experience.
Speaker 2: Absolutely, and this control becomes even more apparent when we
Speaker 2: look at how Apple manages applications on its platforms yep,
Speaker 2: from installation to uninstallation. Ah.
Speaker 1: App management the gatekeeper of the Apple ecosystem. You could
Speaker 1: say that it's how they maintain that famous walled garden, right, yeah,
Speaker 1: you could say that. But before we delve into the
Speaker 1: walled garden and all its implications, let's trace the evolution
Speaker 1: of app management on Apple platforms. Okay, remember back in
Speaker 1: the early days of Macois, when installing an app was
Speaker 1: as simple as dragging an icon to your applications folder.
Speaker 2: Those were the days, simpler times.
Speaker 1: It was a simpler time, yeah, it was. But as
Speaker 1: the Mac platform grew in popularity and the Internet became
Speaker 1: a more let's say complex and sometimes even like a
Speaker 1: dangerous place. Sure, the need for increased security became very apparent,
Speaker 1: and that's where things like code signing and sandboxing come in.
Speaker 2: Right.
Speaker 1: Okay, time for a quick security lesson. Okay, code signing,
Speaker 1: as I understand it, is like a digital signature that
Speaker 1: verifies the identity of the developer, ensures that you know
Speaker 1: that the software hasn't been campered with. And then sandboxing
Speaker 1: is basically like putting the application in a little walled garden, right,
Speaker 1: restricting its access to system resources and your personal data
Speaker 1: so that prevents malicious or poorly coded apps from causing
Speaker 1: damage or stealing information exactly. So these mechanisms, they're all
Speaker 1: about protecting the user and the system from potential threats.
Speaker 1: It sounds like Apple's approach to security has really evolved
Speaker 1: significantly over the years. But how do these security measures
Speaker 1: affect how apps are installed on macOS today?
Speaker 2: Well, while you can still drag and drop applications onto
Speaker 2: your system, mac Os now actually enforces code signing for
Speaker 2: applications that are downloaded from outside the MacApp Store. Okay,
Speaker 2: so if you try to open up an unsigned application,
Speaker 2: you're going to get a security warning, got it, and
Speaker 2: the system will just prevent it from running unless you
Speaker 2: very specifically override those security settings.
Speaker 1: That makes sense. Better to be safe than sorry, right,
Speaker 1: But what about applications that are downloaded from the MacApp Store?
Speaker 2: Yeah?
Speaker 1: Are they also subject to these security checksutely?
Speaker 2: In fact, Apple takes security even further. Oh wow, with
Speaker 2: those app store applications. Okay, they've got this rigorous vetting
Speaker 2: process that scrutinizes application for both security and quality. Got it,
Speaker 2: and all applications distributed through the MacApp Store are sandboxed
Speaker 2: by default, further limiting their potential impact.
Speaker 1: Interesting. So it sounds like Apple has created this multi
Speaker 1: layered security fortress around macOS applications. But what about uninstallation?
Speaker 1: Is it still as simple as dragging an app.
Speaker 2: To the trash in most cases? Yes? Okay, but it's
Speaker 2: worth noting that applications can install components in various system locations,
Speaker 2: not just within their own application.
Speaker 1: Bundle, So simply deleting the application might not actually remove
Speaker 1: all of its associated files and settings, and that could
Speaker 1: lead to like clutter and wasted disk space.
Speaker 2: You got it.
Speaker 1: So that's why a lot of developers now provide like
Speaker 1: uninstaller scripts or utilities to ensure like a clean and
Speaker 1: complete removal exactly. And of course there's those third party
Speaker 1: uninstaller applications that can help clean up any like lingering remnants.
Speaker 1: So even though macOS allows for some flexibility and how
Speaker 1: you manage applications, it's clear that security is a top priority.
Speaker 1: But what about iOS? How does app management differ on
Speaker 1: Apple's mobile platform?
Speaker 2: Well, iOS was designed from the ground up with a
Speaker 2: much more controlled environment in mind. Oh okay, think about
Speaker 2: it as that walled garden ah we talked about earlier,
Speaker 2: carefully curated, Okay, tightly controlled by Apple.
Speaker 1: Right, the infamous walled garden. Yeah, so no more drag
Speaker 1: and drop freedom on iOS then not really? Yeah.
Speaker 2: While you can technically sideload apps onto iOS devices using
Speaker 2: developer tools and enterprise certificates, for the vast majority of users,
Speaker 2: the app store is the only way to install applications,
Speaker 2: so Apple.
Speaker 1: Has complete control over what apps are allowed on its
Speaker 1: mobile platform.
Speaker 2: Right.
Speaker 1: I can see how some people might see that as
Speaker 1: like a restriction, but it also provides a certain level
Speaker 1: of safety and consistency.
Speaker 2: And this control yeah, actually extends to the uninstallation process too.
Speaker 2: Oh Okay, Uninstalling an app on iOS is incredibly simple.
Speaker 1: Yeah.
Speaker 2: You just tap and hold its icon until it wiggles,
Speaker 2: and then you tap the little X that appears. No
Speaker 2: need to worry about those residual files or settings. Yeah,
Speaker 2: iOS handles all that behind the scenes.
Speaker 1: It sounds pretty seamless and user friendly, but it also
Speaker 1: kind of raises some questions about the trade offs between
Speaker 1: you know, like user freedom and Apple's control over the
Speaker 1: app ecosystem. What are like the implications of this approach
Speaker 1: for both developers and users.
Speaker 2: That's a really big question, yeah, and one that deserves
Speaker 2: a deeper dive. On the one hand, this control allows
Speaker 2: Apple to curate this high quality, secure app ecosystem, which
Speaker 2: benefits users by minimize their exposure to malware and ensuring
Speaker 2: that consistent experience. Now, on the other hand, it can
Speaker 2: limit developer freedoms and sometimes stifle innovation by imposing those
Speaker 2: strict guidelines and fees. Okay, it's a complex issue with
Speaker 2: no easy answers.
Speaker 1: It sounds like there are valid arguments on both sides.
Speaker 1: Maybe we can explore those nuances in a future episode
Speaker 1: that's straight, but for now, I think we need to
Speaker 1: shift gears and dive back down to the lower levels
Speaker 1: of the operating system. We talked about Darwin, the Unix Foundation,
Speaker 1: and xn U hybrid kernel, but I think it's time
Speaker 1: we really explore the microkernel legacy of MOCK right in
Speaker 1: a bit more detail. MOCK the tiny kernel that could.
Speaker 1: I'm ready to learn more about its journey to becoming
Speaker 1: the heart of XNU great.
Speaker 2: To understand Mock's significance, we need to take a little
Speaker 2: trip back in time to the mid nineteen eighties. This
Speaker 2: was a time of just rapid innovation in the world
Speaker 2: of operating systems. At Carnegie Mellon University, there was a
Speaker 2: team of researchers led by Richard Rashid, and the embarked
Speaker 2: on this ambitious project to create a new kind of kernel,
Speaker 2: a microkernel they called mach. Their goal was to.
Speaker 1: Welcome back before we took that little detour into app management,
Speaker 1: we were about to learn about MOCK and its journey
Speaker 1: to the heart of xn U. I'm really curious to
Speaker 1: hear what the researchers at Carnegie Millon were trying to achieve.
Speaker 2: Well back then, operating systems they were typically monolithic, meaning
Speaker 2: that all the core functions were very tightly integrated into
Speaker 2: a single large kernel, and this made them really difficult
Speaker 2: to modify and maintain. Oh okay, So the Mock team
Speaker 2: wanted to break free from this monolithic model by creating
Speaker 2: a smaller, more streamlined kernel that delegated as much functionality
Speaker 2: as possible external servers.
Speaker 1: Gotcha. So instead of one giant brain doing everything, yeah,
Speaker 1: you have this network of like a smaller brains, each
Speaker 1: specializing in a specific task.
Speaker 2: Exactly. In this approach, it's known as like a client
Speaker 2: server model, and it offered several advantages. Okay, like what, Well, First,
Speaker 2: it enhanced flexibility by decoupling kernel functions into these independent servers,
Speaker 2: Developers could modify or replace these servers without affecting the
Speaker 2: stability of the core kernel itself.
Speaker 1: So it's like swapping out parts of a machine without
Speaker 1: having to shut down like the entire operation exactly. Yeah, okay,
Speaker 1: that makes sense. Yeah, but wouldn't that also create potential
Speaker 1: security risks? Like if any server can be replayers, couldn't
Speaker 1: a malicious ones slip in?
Speaker 2: That's a valid concern. Yeah, and security is always a
Speaker 2: consideration of system design. But the Mock team they believed
Speaker 2: that the benefits of nodularity outweighed the risks, especially you know,
Speaker 2: if you had proper security measures place. Plus, remember that
Speaker 2: MOCK at this point was really just a research project,
Speaker 2: so exploring these trade offs was really a big part
Speaker 2: of the process.
Speaker 1: Okay, so flexibility was one advantage. What were some of
Speaker 1: the other benefits of this client server model?
Speaker 2: Another key benefit was portability. Mock was designed to be adaptable,
Speaker 2: capable of running on a variety of hardware platforms. This
Speaker 2: was achieved by isolating that hardware specific code in external servers,
Speaker 2: which allowed that core MOCK kernel to remain relatively platform agnostic.
Speaker 1: So it's like having a universal translator for operating systems.
Speaker 1: It could speak the language of different hardware platforms without
Speaker 1: having to rewrite its core code. Yeah, that's pretty impressive
Speaker 1: for a project from the nineteen eighties.
Speaker 2: It really was. Yeah, it was a groundbreaking approach and
Speaker 2: it laid the foundation for the microkernel based operating system
Speaker 2: that we see today.
Speaker 1: Got it. But how did this innovative kernel make its
Speaker 1: way into the world of Apple. Well, you mentioned earlier
Speaker 1: that Apple's X and U kernel is a hybrid like
Speaker 1: that incorporates Mock. How did that come about?
Speaker 2: Well, as Mock matured, it found its way into a
Speaker 2: number of operating system projects, okay, including next T step.
Speaker 2: This is the OS developed by Steve Jobs company next
Speaker 2: T okay. Yeah, or that branching tree we talked about
Speaker 2: before I do. Next step was one of those branches okay,
Speaker 2: and it had Mock at.
Speaker 1: Its core, got it. So when Apple acquired next T
Speaker 1: in nineteen ninety six, they inherited not only Steve Jobs
Speaker 1: but also his Mock based operating system exactly.
Speaker 2: Yeah. And Apple recognized the potential of Mock's microkernel architecture,
Speaker 2: but they also knew that it needed to be adapted
Speaker 2: to really meet the demands of a commercial operating system.
Speaker 1: Right, Like a research project is one thing, yeah, but
Speaker 1: a real world operating system used by millions of people
Speaker 1: is a whole other ballgame.
Speaker 2: It is, Okay. So they took the mock microkernel from
Speaker 2: next step and combined it with components from BSD, another
Speaker 2: Unix derivative, to create a hybrid kernel XNU hybrid.
Speaker 1: So it's not a pure microkernel like the original MOCK,
Speaker 1: that's right.
Speaker 2: XNU is a blend of Mock's modularity with bsd's proven
Speaker 2: stability and performance.
Speaker 1: Ah.
Speaker 2: Taking the best aspects of both approaching right to create
Speaker 2: this kernel that's both flexible and robust. It's kind of
Speaker 2: like combining the agility of a sports car with the
Speaker 2: reliability of a truck.
Speaker 1: I like that analogy. So, what are some like real
Speaker 1: world examples of how this hybrid approach plays out in
Speaker 1: the Apple ecosystem. How does it affect the performance of
Speaker 1: my iPhone?
Speaker 2: For example, Well, mock's message passing system, which allows different
Speaker 2: parts of the OS to communicate very efficiently. That actually
Speaker 2: contributes to like the responsive TOOS.
Speaker 1: Oh Okay.
Speaker 2: Meanwhile, bsd's focus on stability ensures that your iPhone rarely
Speaker 2: crashes even when you're running multiple applications.
Speaker 1: So it's like a well coordinated team. Each member has
Speaker 1: their strengths, yeah, and they work together seamlessly to deliver
Speaker 1: that smooth user experience exactly. I'm starting to appreciate just
Speaker 1: how much thought and engineering goes into creating an operating system. Yeah,
Speaker 1: that feels so intuitive and effortless to use.
Speaker 2: It is, and it's a testament to the ingenuity of
Speaker 2: the engineers at Apple and to the legacy of researchers
Speaker 2: like Richard Rashid and his team over Carnegie Mellon, who
Speaker 2: paved the way for these microkernel based systems.
Speaker 1: Speaking of letacies, let's go back to the filesystem for
Speaker 1: a moment. Sure, Earlier you mentioned that Apple's approach to
Speaker 1: partitioning the file system is quite clever. Can you elaborate
Speaker 1: on that a little bit?
Speaker 2: Sure, As you may recall, Apple separate it's the system
Speaker 2: partition where the operating system is from the data partition
Speaker 2: where all your personal files and apps are stored. Okay, Yeah,
Speaker 2: Now this separation might seem like a minor detail, Okay,
Speaker 2: but it has some pretty significant implications for both security
Speaker 2: and usability.
Speaker 1: Got it? I remember you mentioned that this is what
Speaker 1: allows for like, yeah, there's really seamless system updates, But
Speaker 1: how exactly does that work?
Speaker 2: Well, Because your personal data is stored on a separate partition,
Speaker 2: the system update process can really focus solely on updating
Speaker 2: those system files without touching your photos, your videos, your documents,
Speaker 2: or your app data. This means you can update your
Speaker 2: device without worrying about losing any of your precious information.
Speaker 1: Ah. That's such a relief. I've definitely had my fair
Speaker 1: share of update nightmares on other platforms where I had
Speaker 1: to back up everything before installing an update, just in
Speaker 1: case something went wrong. Right, It sounds like Apple's approach
Speaker 1: is much more friendly.
Speaker 2: It is. Yeah, and this focus on user experience is
Speaker 2: evident in many aspects of Apple's OS design. Okay, for example,
Speaker 2: let's revisit those dot dmg files we talked about earlier. Okay, Yeah,
Speaker 2: remember how they're essentially mini file systems.
Speaker 1: Yeah, it's like having that tiny, self contained drive within
Speaker 1: a file. Yeah, this is a pretty interesting concept. Well.
Speaker 2: This approach to software distribution has several benefits. First, it
Speaker 2: allows Apple to create a more controlled and consistent installation experience.
Speaker 2: It can package the application, it's resources, any necessary documentation
Speaker 2: within a single, easily manageable unit.
Speaker 1: So it's like a neatly packaged gift box. Yeah, everything
Speaker 1: you need is right there, ready to go exactly. Yeah.
Speaker 2: Okay, I like that. What else? In Second, it enhances security.
Speaker 2: By using a custom image format like dot DMG, Apple
Speaker 2: can implement security measures, help prevent tampering, and ensure that
Speaker 2: the software year installing is legitimate and hasn't been modified
Speaker 2: in any way.
Speaker 1: So it's like another layer of protection for the user.
Speaker 1: It's interesting to see how all these seemingly small design
Speaker 1: choices all contribute to Apple's overall philosophy of creating a
Speaker 1: secure and user friendly ecosystem.
Speaker 2: Absolutely. Yeah, and this philosophy is perhaps most evident in
Speaker 2: how Apple manages applications platform right. Yeah, we touched on
Speaker 2: this earlier. Yeah, but I think it's worth diving a
Speaker 2: little deeper into the implications of Apple's walled garden approach,
Speaker 2: particularly in the context of iOS.
Speaker 1: Okay, let's talk about the waldgarden. As a user, I
Speaker 1: really appreciate like the sense of security and consistency that
Speaker 1: it provides, knowing that you know, every app I download
Speaker 1: from the App Store has been vetted by Apple. But
Speaker 1: I can also see how this approach could be seen
Speaker 1: as like, especially from a developer's perspective.
Speaker 2: You've hit the nail on the head. It is a
Speaker 2: trade off, and there are definitely valid arguments on both sides.
Speaker 2: On the one hand, apples tight control over the app
Speaker 2: ecosystem allows them to create this highly curated experience for users.
Speaker 2: They can set these very strict guidelines for app quality,
Speaker 2: security content, which helps ensure that users have a positive
Speaker 2: experience with every app that they download. This also benefits
Speaker 2: developers who create those high quality apps as they face
Speaker 2: less competition from poorly made or even malicious apps.
Speaker 1: So it's like a well maintained park. You might not
Speaker 1: have the freedom to do whatever you want, but you
Speaker 1: can be sure that it's safe, clean, and enjoyable for everyone.
Speaker 2: That's a great analogy. Yeah, But of course there's a
Speaker 2: flip side to this coin. Of course, Yeah, apples strict
Speaker 2: control can also stifle innovation. Developers have to adhere to
Speaker 2: Apple's guidelines, which can sometimes be seen as arbitrary or
Speaker 2: even restrictive. They also have to pay a commission on
Speaker 2: every app they sell through the App Store, which of
Speaker 2: course cuts into their profits, and they have very limited
Speaker 2: control over how their apps are marketed and distributed.
Speaker 1: So it's a balancing act. Apple wants to create a
Speaker 1: safe and enjoyable experience for users, but they also need
Speaker 1: to provide developers with the freedom and flexibility to innovate.
Speaker 1: It's a tough challenge. There's no easy answer, it really is.
Speaker 2: Yeah, and this debate is likely to continue as the
Speaker 2: app ecosystem evolves and new technologies emerge. But for now,
Speaker 2: it's clear that Apple's walled garden approach has been successful
Speaker 2: in creating a thriving app market that benefits both users
Speaker 2: and developers.
Speaker 1: It's a fascinating topic and one that we could probably
Speaker 1: spend hours discussing. Oh yeah, but for now, I think
Speaker 1: we need to wrap up this deep dive into the
Speaker 1: core of Apple's OS. We've covered a log ground today,
Speaker 1: from the historical roots of Darwin to the architectural complexities
Speaker 1: of mock, the file system, and the ever evolving world
Speaker 1: of app management.
Speaker 2: It's been quite a journey, yeah, exploring those hidden days.
Speaker 2: It really has of these systems that we interact with.
Speaker 1: Every day, and hopefully our listeners have come away with
Speaker 1: a newfound appreciation for the complexity and ingenuity that goes
Speaker 1: into creating those sleek, user friendly devices that we all
Speaker 1: rely on.
Speaker 2: Absolutely Yeah, So the next time you pick up your
Speaker 2: iPhone or sit down at your Mac, just take a
Speaker 2: moment to reflect on that incredible legacy of innovation and
Speaker 2: engineering that made it all possible.
Speaker 1: And remember, we've only scratched the surface we have. There's
Speaker 1: a whole world of knowledge waiting to be explored within
Speaker 1: every Apple device. So stay curious.
Speaker 2: Stay curious.
Speaker 1: Yeah, keep learning, keep learning, and keep diving deep, Keep
Speaker 1: diving deep. Welcome back, to the final part of our
Speaker 1: deep dive into the world of Apple's operating systems. Before
Speaker 1: we got sidetracked by the whole Walled Garden debate. We
Speaker 1: were about to travel back in time to explore the
Speaker 1: origins of mach microkernel that lies at the heart of XNU.
Speaker 2: Right, Yeah, mock. It was born in the mid nineteen
Speaker 2: eighties at Carnegie Mellon University. It was the brainchild of
Speaker 2: Richard Rashid and his team, and they had this vision
Speaker 2: for a new breed of Colonel Yeah, a microkernel designed
Speaker 2: specifically for flexibility and modularity.
Speaker 1: Now, we talked a bit about these concepts earlier, but
Speaker 1: I'm still a little bit fuzzy on the details. Okay,
Speaker 1: what exactly itam microkernel? And how does it differ from
Speaker 1: a traditional monolithic kernel?
Speaker 2: Okay, Well, imagine a large complex organization like a corporation. Now,
Speaker 2: a monolithic kernel is like having a single CEO making
Speaker 2: all the decisions, managing all the departments, controlling all the resources.
Speaker 1: Got it.
Speaker 2: Now, It's efficient in some ways, but it can also
Speaker 2: be very slow and inflexible.
Speaker 1: So one person trying to micromanage everything, I can see
Speaker 1: how that could get pretty messy.
Speaker 2: Exactly. Yeah. Now, a microkernel, on the other hand, is
Speaker 2: like having a smaller, agile executive team that delegates tasks
Speaker 2: to specialized departments. Each department has its own responsibilities and resources,
Speaker 2: and they communicate with each other through well defined channels.
Speaker 1: So instead of like one central authority, you have this
Speaker 1: network of smaller, more specialized unit working together.
Speaker 2: Exactly.
Speaker 1: It sounds like a more decentralized and adaptable.
Speaker 2: Approach precisely, and that was the key insight behind mock.
Speaker 2: By breaking down the kernel into smaller, more manageable components,
Speaker 2: the researchers at Carnegie Mellon they were really aiming to
Speaker 2: create this more flexible, portable, and maintainable operating system.
Speaker 1: This all sounds like very forward thinking for the nineteen eighties.
Speaker 1: It was what were some of the specific challenges that
Speaker 1: they were trying to address with this whole microkernel approach.
Speaker 2: One of the biggest challenges back then was portability. At
Speaker 2: the time, operating systems were often very tightly coupled to
Speaker 2: specific hardware architectures, and this made it extremely difficult and
Speaker 2: time consuming to port an operating system to a new
Speaker 2: type of computer.
Speaker 1: So if you wanted to run the same operating system
Speaker 1: on say like a desktop computer and a laptop, you'd
Speaker 1: practically have to rewrite the entire thing essentially.
Speaker 2: Yeah. Wow, Okay, the Mock team wanted to create this
Speaker 2: kernel that could be very easily adapted to different hardware platforms,
Speaker 2: making it way more versatile and future proof.
Speaker 1: That makes sense. Yeah, but whatn't breaking down the kernel
Speaker 1: into smaller pieces also introduce, you know, sure, new challenges
Speaker 1: like how do you make sure that all these different
Speaker 1: components work together seamlessly?
Speaker 2: That's a great question. Yeah, and it's one of the
Speaker 2: key areas where the Mock team really made significant contributions.
Speaker 2: They actually developed this very sophisticated message passing system that
Speaker 2: allows those different kernel components or servers to communicate with
Speaker 2: each other efficiently and reliably.
Speaker 1: So it's like having this secure and efficient communication network
Speaker 1: within the kernel itself. Each component can basically send messages
Speaker 1: to other components, requesting services or sharing information exactly. That
Speaker 1: seems really clever.
Speaker 2: Yeah. It was a groundbreaking innovation at the time. Wow,
Speaker 2: And it leads to the foundation for those microkernel based
Speaker 2: systems that we still see today.
Speaker 1: So Mark, was this like revolutionary microkernel? Yeah, designed for
Speaker 1: flexibility portability. How did it end up becoming like the
Speaker 1: heart of Apple's operating systems Well.
Speaker 2: As we discussed earlier, when Apple acquired next T in
Speaker 2: nineteen ninety six, they inherited next T STEPH, which of
Speaker 2: course was built on that mock microkernel. And Apple's engineers, Yeah,
Speaker 2: they saw the potential of mach okay, but they also
Speaker 2: recognized that it needed to be adapted to meet the
Speaker 2: demands of a commercial operating system, right, Like.
Speaker 1: A research project is one thing, but a real world
Speaker 1: operating system used by millions of people is a whole
Speaker 1: other ballgame.
Speaker 2: It really is. So Apple's engineers they took that mock
Speaker 2: microkernel and they combined it with components from BSc, another
Speaker 2: Unix derived system known for its stability and performance. The
Speaker 2: result was xn U x U, a hybrid kernel.
Speaker 1: Hybrid kernel that takes advantage.
Speaker 2: Of both the microkernel and monolithic approaches.
Speaker 1: So it's not like a pure microkernel like the original
Speaker 1: moch No, it's.
Speaker 2: More of a hybrid, a blend of different approaches. Does
Speaker 2: that mean it's not as flexible or portable as mock
Speaker 2: was initially designed to be? This is a valid question now.
Speaker 2: While XNU is not a pure microkernel, it retains many
Speaker 2: the benefits of Mock's modularity. For example, that message passing
Speaker 2: system developed for MOCK is still a very core part
Speaker 2: of XNU.
Speaker 1: Wow.
Speaker 2: It allows the different components of the kernel to communicate
Speaker 2: very efficiently.
Speaker 1: So even though it's been adapted and integrated into this
Speaker 1: more complex system, Mock's legacy lives on. It does in
Speaker 1: the heart of Apple's operating systems precisely.
Speaker 2: Yeah, and this blend of approaches, Yeah, it's proven to
Speaker 2: be remarkably successful.
Speaker 1: That's pretty cool.
Speaker 2: XNU provides that foundation for the responsiveness, the stability, the
Speaker 2: security that Apple devices are known for.
Speaker 1: It's amazing to think that, like a research project from
Speaker 1: the nineteen eighties continues to shape the digital experiences of
Speaker 1: millions of people today.
Speaker 2: It's incredible.
Speaker 1: Yeah, it really shows like the enduring power of innovation
Speaker 1: and the importance of building on the work of those
Speaker 1: who came before us.
Speaker 2: Couldn't have said it better myself.
Speaker 1: Well, I think it's time to wrap up our a
Speaker 1: deep dive into the core of Apple z os. We've
Speaker 1: covered a lot of ground today, from the historical roots
Speaker 1: of Darwin to the architectural complexities of MOCK. The file system,
Speaker 1: and the ever evolving world of app management.
Speaker 2: Absolutely yeah, it's been quite a journey. It really has,
Speaker 2: exploring those hidden depths of these systems that we interact
Speaker 2: with every day.
Speaker 1: It really has, and hopefully our listener have come away
Speaker 1: with a newfound appreciation for the complexity and the ingenuity
Speaker 1: that goes into creating those sleek, user friendly devices that
Speaker 1: we all rely.
Speaker 2: On every day. So the next time you pick up
Speaker 2: your iPhone or sit down at your Mac, just take
Speaker 2: a moment to reflect on that incredible legacy of innovation
Speaker 2: and engineering that made it all possible.
Speaker 1: And remember we've only scratched the surface.
Speaker 2: We as a.
Speaker 1: Whole world of knowledge waiting to be explored. There is
Speaker 1: within every Apple device, absolutely so stay curious, stay curious,
Speaker 1: keep learning, cap learning, and keep diving deep.
Speaker 2: Keep diving deep,