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Twitter Client for UEFI

github.com

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Re: Twitter Client for UEFI

#51

Post by saghm »

silisili wrote: post #20
ctxc wrote: post #10

Didn't know what UEFI was, so here it is: " UEFI and BIOS are low-level software that starts when you boot your PC before booting your operating system, but UEFI is a more modern solution, supporting larger hard drives, faster boot times, more security features, and—conveniently—graphics and mouse cursors. The UEFI/BIOS loads when your computer starts up, and the BIOS is responsible for waking up your computer’s hard…

Thanks for this. I had a generally good idea about this, but despite seeing the word for many years, never actually knew what POST stood for before this comment. I'm not even sure I knew that it was an acronym...

Yeah, I always assumed it meant "post" as in "after", and it meant "after starting up" or something

Re: Twitter Client for UEFI

#53

Post by dijit »

blibble wrote: post #40
dijit wrote: post #35

Earlier quoted context omitted.

> if you're so inclined: you can remove unneeded modules from your UEFI firmware this is so disingenuous as to be offensive. I'm not saying you're wrong, but the practical options for replacing a UEFI BIOS are vanishingly small. Also: booting over the network is a feature of a smaller ROM on a network card, that ROM usually had a much smaller surface area and had to be explicitly called as a boot option. Given the pe…

> this is so disingenuous as to be offensive. > I'm not saying you're wrong, but the practical options for replacing a UEFI BIOS are vanishingly small. what? you can download a GUI editor, click remove on the modules you don't want and then save it https://www.trishtech.com/2017/12/uefitool-view-and-edit-uef... I've done it

Cool tool, didn’t know it existed but there are so many variations on UEFI bios’s that I can’t help but feel it will not universally work, and it depends a lot on things being compartmentalised.

I also draw your attention to:

> UEFITool is only meant for the advanced users who have all the knowledge needed to modify the UEFI BIOS files. Because of you make any mistake and flash the faulty file to your motherboard, it can turn the motherboard into a dead brick.

Which is more worrying when you look at what is presented (just a bunch of UUIDs). Not exactly usable for average person who wants to minimise the attack surface of their machine.

Given that average people aren’t networking booting, wouldn’t it be wiser to have it enableable? Instead of on by default.

Re: Twitter Client for UEFI

#56

Post by mwcampbell »

bayindirh wrote: post #31
blibble wrote: post #27

Earlier quoted context omitted.

what's the difference between having the code running in ring0 in a ROM vs the code running in ring0 from UEFI?

When a boot ROM fires (it was via INT19 IIRC), the boot ROM runs, terminates and leaves the system. The size is smaller, it's not persistent, and it can't communicate with anything on the OS. When booted from the ROM, it just downloads pxelinux.0 binary in most cases, and transfers control to it, and just vanishes. The UEFI is persistently running at the background, has communication pipes with the OS (some of it is…

> There's also at least one open source sound driver too

Looking on the bright side, that means the firmware can potentially also talk to you if you can't see the screen.

Re: Twitter Client for UEFI

#57

Post by monocasa »

rvz wrote: post #37
shrimp_emoji wrote: post #30

Earlier quoted context omitted.

Quoted post unavailable.

It's because 95% of people do not care or don't like playing around with their computers or accessing the UEFI menu for sys-admin, netbooting, recovery, ransomware development or building their PCs. Apple does the same thing without the spooky UEFI menus on PCs, called 'Internet Recovery' which is still using EFI and is just like how netbooting works; and that 'just works' .

The filevault unlock screen interestingly enough is an EFI application, carefully constructed to look like the normal login screen. It's probably the most used EFI app that normal users interact with.

Re: Twitter Client for UEFI

#58

Post by secondcoming »

p_l wrote: post #6
secondcoming wrote: post #4

TIL: It's possible for UEFI code to access the internet. What could possibly go wrong?

How did you think netbooting support works? UEFI made it quite simpler by making it so that network cards only have to bring a driver in OPROM instead of whole stack as before, and this allowed important improvements into boot process (like HTTPS instead of TFTP)

I thought that was the Intel ME thing. I've actually never used netboot.

Re: Twitter Client for UEFI

#60

Post by Sophira »

WaitWaitWha wrote: post #28

/s Gather around children. Let me tell you a story from long long time ago. Two one eyed giants, Intel and Microsoft got together and decided that they should be in control of your machine, not the other half giants, like AMI, Award,Phoenix, DTK, and even a full giant but nobody cared about her, IBM. So they convinced everyone there was no space on the BIOS any more, and they had to shift much of the code outside ont…

> and finally your very safe and secure OS running.

That's the one running on the Intel Management Engine, right? Or at least Intel would like to believe that's the case.

Jokes aside, I may be missing something. The BIOS came way before UEFI did. What am I missing here?

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