Also it's not very interesting either. At simplest, Linux just needs to take a pointer to a beginning of a framebuffer and some metadata, and will write to the framebuffer whenever there's something to update.
edit: Apparently it's a desktop motherboard firmware thing. Ubiquitous but not technically a requirement for POSTing a computer.
Also, in 2000 when Windows crashed you could get a serial debugger. Wonder if they still do that?
It is a unique monstrosity that boots from the video / GPU core instead of one of the ARM cores. It has an arcane undocumented architecture.
https://www.amazon.com/-/he/Developing-32-Bit-Operating-Syst...
physical_address = (segment << 4) + offset
These blog posts really annoy me because I feel like with 20% more effort you could have something worth reading.
<body>
<!-- Femboy Mode Button - Hidden on Mobile -->
<button class="rave-button" id="raveButton" onclick="toggleRaveMode()" title="Femboy Mode" style="display: none;">
<span class="button-text">uwu</span>
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* The Linux Boot Process: From Power Button to Kernel
* The Journey Before main()
* How programs get run: ELF binaries (2015) (lwn.net)
This post skips all the interesting things in the modern firmware dance. Not the least of which is when you call ExitBootServices() you're already in long mode. There's no need for the journey through real and protected.
https://webaim.org/resources/contrastchecker/
(this is the site: https://webaim.org/resources/contrastchecker/?fcolor=D0D0D0&...)
> Hex is base 16
i would argue that someone that understand bases (in the first place), understands what the << operator does (context where base 16 is explained), but doesn't understand what base 16 is, doesn't exist. this is the kind of haphazard approach of this article i'm talking about. even the author's name, 0xkato, is an example of this.
as to the content, i wish it had touched on TPM, PCRs, UEFI secure boot, and ME pre-boot.
i'm forgiving all the actual errors since it is a pretty broad overview.
i'm guessing first-year uni student.
rather amazed a post like this can make it to the #1 spot.
At the same time this doesn't address my biggest open question on the topic - how do we get from the physical push to the reset vector? Somehow that magic works in HW, physics and electronics - how?
There is a well praised post on HN: https://www.nan.fyi/database, built with the framework: https://github.com/nandanmen/NotANumber
pixelbeat__•3h ago
Here are some details: https://www.pixelbeat.org/docs/disk/