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zepto

Android is a real Linux in the same way that iOS is a real BSD Unix.

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No, I don't think that's true. Android is just Linux with an Android userland.

Richard Stallman was quite correct to call it GNU/Linux, as much as I dislike the guy.

iOS is just BSD/Mach with an iOS Userland. Here is the kernel: https://github.com/apple/darwin-xnu

Yes. it's accurate to describe iOS as iOS/Darwin, and macOS as macOS/Darwin. But "BSD" implies a BSD userland to most people, which macOS has but iOS doesn't.

Linux implies a GNU userland to most people which Android does not have.

Alpine Linux is unequivocally a Linux despite not having much to do with GNU in userland.

It has a work-alike of the gnu userland.

Well, that's precisely what Stallman was trying to address, wasn't he? Trying to separate out the Linux kernel from the GNU userland.

Yes, but he had failed before he even started trying to get people to say GNU/Linux instead of Linux.

That’s my point - when people say Linux they generally mean GNU/Linux not Android.

Equally, people are generally not talking about only the kernel, when they say Linux. Usually when someone is talking about only the kernel they say ‘the Linux kernel’.

GNU/Linux usually only gets used by the FSF or during discussions of this kind.

“Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.” [1]

[1] https://en.wikipedia.org/wiki/Linux

It's a long term pattern that keeps playing out to say "Richard Stallman was quite correct <insert topic here>, as much as I dislike the guy."

Maybe we should pay more attention to what he says!

Except that you are only allowed to use these Linux calls,

https://github.com/aosp-mirror/platform_bionic/blob/master/d...

Anything not white listed on the LinuxSE and seccomp configurations, just has as outcome killing the "naughty" app.

The opposite tho. Darwin uses a BSD userland (and a proprietary GUI stack) atop a custom kernel while Android is a Linux kernel with a custom userland (and again a proprietary GUI stack.)

They do both use bash tho ;)

Used to. Macs switched to zsh :-)

What? Android’s kernel is a pretty close derivative of upstream Linux while iOS’ kernel has almost nothing to do with any current BSD distribution.

iOS kernel is Darwin, a current BSD: https://github.com/apple/darwin-xnu

Darwin only half BSD. It uses a Mach kernel and Bash but BSD utilities instead of coreutils. It’s development and administrative utilities along with its init system are custom as well.

Fair enough, but that still means this statement (made by ArgylSound): “iOS’ kernel has almost nothing to do with any current BSD distribution.” is false.

XNU, Darwin's kernel, is Mach + FreeBSD[1].

[1] https://github.com/apple/darwin-xnu

For more background, see https://developer.apple.com/library/archive/documentation/Da...

There it clarifies that it is "mostly" FreeBSD. The Mach being used also differs significantly from CMU Mach and what you might find by looking for Mach3/4 source dumps.

One of the biggest challenges in "converting" NeXTSTEP (MacOS's predecessor) to OS X was both updating software to newer versions and eliminating expensive licenses from AT&T and Adobe.

NeXTSTEP was a "capital U" UNIX with AT&T proprietary code, based on 4.3/4.4BSD (encumbered). Every copy needed a UNIX license and royalties to AT&T.

NeXT was based on Mach2, which had 4.3BSD deeply integrated into the kernel source tree. Device drivers were both native BSD ones along with a "DriverKit" interface that used Mach messages to write userland device drivers.

CMU Mach v3 and v4 cut out all the BSD code and put it into a userland "UX Server", a model incompatible with NeXT. So instead, Apple took the OSF/1 Mach kernel, derived from Mach 2.5, and replaced the BSD subsystem code with 4.4BSD-lite, gradually updating its subsystems with FreeBSD ones.

So TLDR, Darwin/XNU has both a BSD userland and essentially a FreeBSD kernel. When you make a "UNIX-y" syscall from C in MacOS, you're "talking" to a "FreeBSD kernel".

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