The wonderful world of UEFI [or not].

Member 15078716

I was going to post this as an article since someone might be searching for UEFI information, but it is not about code so I placed it here. If someone would like to make this an article, then that is fine. Thank you. It started out as an answer or comment to https://www.codeproject.com/Questions/316940/Coding-an-OS-for-a-specific-system https://www.codeproject.com/Questions/316940/Coding-an-OS-for-a-specific-system So, now the title is The wonderful world of UEFI [or not]. I know this is an old disucssion, but someone might be searching for UEFI information and how to write a UEFI loader, or write to UEFI, or how to read UEFI, or how to remove UEFI, or how to edit UEFI. Specifically, what this person is asking can be done with the UEFI. UEFI is commonly written and installed by various hardware manufacturers. It is a part of some motherboards: Many times on a UEFI containing chip that is burned into the chip making it changeable only by replacing that chip. Some times it is in changeable memory on the motherboard. The same can be said of UEFI with video cards, and sound cards, and network cards, which include those that come with the system and those that are sold separately via retail. They can be burned into a chip or in memory on those cards. You said,

Quote:

it turns out, that UEFI is 'merely' a layer on top of the BIOS, a pseudo OS, to make OS's more portable.

No that assumption is wrong. It is not a layer on top of BIOS: It is ment to be a replacement to BIOS. I can be attached to older systems BIOS where the BIOS has irrevocable control, but UEFI is meant to be a replacement for BIOS completely. You said,

Quote:

, to make OS's more portable.

That is specifically wrong. UEFI was originally designed to work on, or with, or in extension of, or to contol non-server operating systems, specifically to allow a remote entity to completely control the non-server operating system. Notice that was for a "remote entity", which means that with it anyone that had the login sequence may have (at UEFI's first introduction) been able to use and control and override and change any software part of the operating system and the files on it to furthermore include all of that for the mouse, the keyboard, the monitor, the microphone, the camera, etc. either the same as or similar to if

Nelek

You could post it as a tip

M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.

Ron Anders

It seemed like a bad idea. Viva La Basic Input Output System.

jmaida

excellent subject. I was introduced to UEFI recently with a desktop I acquired a year or so ago, which has a UEFI and BIOS, a tweener, I guess. Did some research but not so much as you have. Thanx. BYW, I power off my desktops by removing power source. Unless their mother batteries are something special they should not be alive to accept instructions without power. Thanx again for raising this topic for discussion.

"A little time, a little trouble, your better day" Badfinger

Richard Andrew x64

Excellent post. Question: Is the UEFI or BIOS only there to initialize the system and check the signature of the OS (plus do all the other things you mentioned,) or does the OS call into the firmware to perform basic tasks?

The difficult we do right away... ...the impossible takes slightly longer.

Member 15078716

I am not quite certain what you mean by that reply. If someone watches the input/output of a system from within that system and thinks to catch the UEFI remote control activity, they might be surprised to note that the UEFI can be an entirely different and fully operational independent operating system, with activity not easily viewable from what a common user thinks is them viewing all. It is not always that way, but under certain circumstances it can be. It looks like beginning with service pack [*] of Winsnos (spelling again) [*] that might have been a future goal: to lock the user from detecting UEFI activity including blocking the user from detecting the UEFI's remote communications. This site should have a dedicated discussion group for UEFI. I do not have enough points at this time to create that.

OriginalGriff

Member 15078716 wrote:

This site should have a dedicated discussion group for UEFI. I do not have enough points at this time to create that.

Only the admins can add or remove forums; you would need to ask them directly: Bugs and Suggestions[^] is the place to do that. I'm not sure they will agree with you though: it's a bit of a "niche subject" that is unlikely to get much traffic on a generic development site like this.

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt AntiTwitter: @DalekDave is now a follower!

Member 15078716

You are welcome.

Member 15078716

The UEFI is there for the same reason that server software has had similar for years. I was a consultant years ago and when I heard a woman (in a different office from where I was working) exclaim something in surprise; I went there and noticed that she had her hands lifted and away from her computer. I looked at the screen and the mouse cursur was moving and there was clicking on items while she did not touch the keyboard or mouse. I told her that it was probably someone in the network administration either new to the capacity of remote control or someone, probably in network adminstration, teasing her. She said that it happened often, but the other people in adjacent offices did not seem to have had that experience. I suggested to her that she go to the admin office and see who was there. That was years ago, way before UEFI. This is nothing new. The lies told about UEFI being just for booting and being just for large file systems and being just for 64 bit seem to be believed by the masses. UEFI on a personal computer is like a very advanced version of the remote control that has been an integral part of business server software. Maybe some of you remember Windows NT-4, which could be made to be hacker proof? Now, the hacker proof part has and is being, at least attempted to become, changed to impossible to stop hackers. I started in card punch input and readers where we punched in a bunch of cards then submitted them to a physical box and hoped that they were run with a result when we came back to that class the next time. I do not even remember which college I was attending at the time. I do not expect that they had remote control back then, but I do remember it later in NT4. It is not for boot loading. It is for remote control, and other things. UEFI is just a program. It can be a complete shadow operating system running all the time if there is sufficient electrical power in the system, all the while being forcefully hidden from the average user. This site should have a publicly readable discussion group just for and dedicated to UEFI: the use of, the programming of, the monitoring of, the intricate analysis of UEFI.