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Comment by hn_submit

4 hours ago

I've always been downright suspicious of the creation of UEFI. It executes code before the operating system but doesn't really provide a hardware abstraction layer like BIOS does. Most operating system don't use BIOS or any other software layer and configure the hardware themselves. Why is it there then?

And unlike BIOS which is relatively small UEFI is "full-fat" almost the size of an operating system itself. It can even run its own applications.

The 1 million lines of C code comprising UEFI are riddled with bugs and this is just one of them. No doubt LLMs will be able to uncover a lot more of them.

6 comments

hn_submit

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yjftsjthsd-h  2 hours ago

> It executes code before the operating system but doesn't really provide a hardware abstraction layer like BIOS does.

Yes it does? If anything, it provides way more; a .efi program can use firmware services to load files and print text. There's like 80% of a DOS in there.

> Most operating system don't use BIOS or any other software layer and configure the hardware themselves. Why is it there then?

Because we still want enough functionality to load the OS in the first place, which means e.g. nvme drivers, Ethernet drivers (for netboot), keyboard input and some display output (to let a user pick what to load), and of course filesystem drivers because loading an OS/bootloader from a single shared MBR was awful.

  • preisschild  1 hour ago

    they also provide device trees to the kernel on modern arm uefi environments. And in servers they provide an interface for the baseboard management controller to interact with the firmware directly.

mjg59  4 hours ago

> doesn't really provide a hardware abstraction layer like BIOS does

I'm not really sure what this means. UEFI provides a consistent interface to access storage devices, network devices, input devices, and access to a framebuffer. How else would bootloaders work?

imoverclocked  4 hours ago

Well, looking at the mess that is most arm/arm64 SBCs, I understand why it’s nice to have a standard interface that can run (eg) grub. Can UEFI be much smaller? Also yes.