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by saagarjha 2886 days ago
> what we have now

x86 processors still boot into real mode…
1 comments
yjftsjthsd-h 2886 days ago
It's my understanding that UEFI actually comes up directly into long mode?

"UEFI firmware performs those same steps, but also prepares a protected mode environment with flat segmentation and for x86-64 CPUs, a long mode environment with identity-mapped paging. The A20 gate is enabled as well."

- https://wiki.osdev.org/UEFI

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dlubarov 2885 days ago
Unfortunately most BIOS services are only available in real mode, so it's often necessary to switch back and forth.
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basementcat 2885 days ago
This inadvertently triggered my A20 gate rage.
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