> More importantly, a kernel is a platform.

Completely agree with this framing. We will get there by the end of the series.

Yeah no. An operating system kernel doesn't just act as a host for userland processes, it interacts with hardware. Hardware behaves in weird and unexpected ways, can be quite hard to debug, can fail, etc.

This is why Linux is excellent. Users of other operating systems often remind people to update their device drivers. A non-technical Linux responds asking what the heck device drivers are. To the casual user, device drivers become invisible because they work exactly as intended.

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charcircuit 3 days ago | parent [-]

The kernel talks to the device using an API it exposes. Similarly Chrome will talk to the OS using an API it exposes. OS APIs can also behave in weird and unexpected ways, be hard to debug and fail. Chrome protects the content it hosts from this complexity. Interacting with the layer underneath you is part of your job of hosting things on top of you.

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tosti 3 days ago | parent [-]

Those are just drivers to stuff that runs its own cpu and interfaces over some kind of serial port. Printers are a well known example of this. Also intel wireless nics with their firmware blobs.

Not are drivers are like that. For instance, drivers/input/serio/ps2-gpio.c is all about timing the right signals.

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charcircuit 3 days ago | parent [-]

You are missing the point. The kernel is still abstracting over those GPIO timings so programs don't need to know the timings themselves. This is the benefit of using a platform. These low level things get abstracted away from what you have to do.

	▲	tosti 3 days ago \| parent [-]
		Oh, I see. You're piecing together the layers much like a cake. The way I see it, everything is tied together as some kind of flow chart where different elements have different jobs. Linux is quite a small part of the system when compared to Google Chrome. Even if you were to invert the cake, as a whole it still wouldn't make sense to me to see it that way. Hardware tends to have more distinct layering than the lalala-land of software where pretty much anything goes.