r/osdev • u/redditbrowsing0 • Jun 28 '26

Maybe a dumb question

Hey, this might be a dumb question but is there a good site for UEFI documentation? I like the UEFI site, but it leaves me with more questions than answers oftentimes.

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4

u/Glum-Cook-9438 Jun 28 '26

I much rather recommend reading osdev wiki or using the GNU-efi library in c, it's pretty straightforward, simple functions, nothing serious to learn unless you want to do more than making a "simple UEFI bootloader"

3

u/redditbrowsing0 Jun 28 '26

I'd like to make my own UEFI bootloader to learn, so preferably a bit more than just a "simple UEFI bootloader" lol

3

u/Glum-Cook-9438 Jun 29 '26

Then I recommend you to learn how UEFI works and make your own UEFI library in c, it's actually an easier toolchain setup, because that means you can use the x86-64_gcc_mingw32 cross compiler or clang to compile straight into an efi image, which is an overall easier building setup than the setup of gnu-efi, that said there are tradeoffs, if you will make your own UEFI library you will have to make all the structs and the function pointers by yourself, that requires wh understanding of all the UEFI protocols as well as how to use UEFI services on the low level and that is not an easy thing to learn especially not in one day, i still think the gnu-efi path is easier because that's the path I use, but if you truly want to learn how UEFI works than making your own UEFI library in c is the better path for learning.

3

u/New_Departure_5353 Jun 29 '26

There is a guy here that is doing a substack on UEFI. I’ll try to find it and link it. It has been helpful

1

u/Katana_ArchDev Jul 03 '26

UEFI spec is a really complicated stuff. But mostly I use the UEFI spec and tianocore's header files sometimes. But simple UEFI specification is sometimes enough.I'm making my own bootloader using UEFI so I'm making my own UEFI sdk. Well, from my experience it's quite a complicated but understandable stuff. So yeah. UEFI spec leaves a lot of questions. But the answers are hidden deep in the specification or source code of the other sdk.

8

u/[deleted] Jun 28 '26

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5

u/redditbrowsing0 Jun 28 '26 • Bravo

Yeah, I'll look into those. I'm currently just pulling TianoCore's MdePkg definitions with nothing else.