READ THIS! (BIOS and UEFI thoroughly explained...)

[mikewalsh]

Afternoon, gang.

I was having a skim through the gParted website a little bit earlier today:-

https://gparted.org/

.....and came across a link to this detailed, yet very readable, thorough explanation as to how BIOS and UEFI - the two main types of PC 'firmware' - actually work:-

https://www.happyassassin.net/posts/201 ... work-then/

It's well worth a read.....and will - hopefully! - dispel several of the more prominent myths that are floating around the web in general circulation. It's cleared up several misconceptions for me. With any luck, it should for you, too.

(I'm posting it in 'Announcements' because I think it's important enough to be here. It's not highly-technical, because it's aimed AT the average home user.....which covers 95%+ of PC users, worldwide.)

Mike.

[rcrsn51]

Good article. But since 2014, UEFI firmware has become more flexible than the article suggests. It is certainly now possible to have several OS's on the same UEFI system. Many UEFI firmware implementations let you mix-and-match BIOS/UEFI with MBR/GPT. For example, you can easily have a bootable flash drive formatted as MBR that can dual-boot BIOS and UEFI machines.

Unfortunately, the predominant attitude in the Puppy forum has long been "I hate Microsoft. I hate Windows. I hate UEFI. I hate Secure Boot. I hate GRUB2", which has hindered progress. Many forum members still consider BIOS+MBR+Grub4Dos to be the Puppy standard.

[rockedge]

@rcrsn51

Remember the days when booting a computer meant installing a bootstrap loader, written in Assembly, converted to Hexadecimal, converted to Octal, then loaded in to RAM manually using toggle switches and indicator lights? Or a real modern take, the bootstrap loader that makes a paper tape reader work came in ROM, so once the machine was on you only had to toggle in with switches the byte to make the computer listen for a paper tape roll and load that with a Teletype 33.

The days when 8 bits was a monster. These boot methods are secure, how many people do you know that can boot a computer with toggle switches?

[rcrsn51]

@rcrsn51

Remember the days when booting a computer meant installing a bootstrap loader, written in Assembly, converted to Hexadecimal, converted to Octal, then loaded in to RAM manually using toggle switches and indicator lights? Or a real modern take, the bootstrap loader that makes a paper tape reader work came in ROM, so once the machine was on you only had to toggle in with switches the byte to make the computer listen for a paper tape roll and load that with a Teletype 33.

The days when 8 bits was a monster. These boot methods are secure, how many people do you know that can boot a computer with toggle switches?

What's your point, vis-a-vis this article?

[mikewalsh]

@rcrsn51 :-

Unfortunately, the predominant attitude in the Puppy forum has long been "I hate Microsoft. I hate Windows. I hate UEFI. I hate Secure Boot. I hate GRUB2", which has hindered progress. Many forum members still consider BIOS+MBR+Grub4Dos to be the Puppy standard.

This is certainly relevant, I'll grant you.

For myself, I don't so much 'hate' Windows as I was simply glad to get away from it. After nearly 30 years, I was more than ready for a change, and so I made it.

As for GRUB2, hm; it's not a case of 'hate' it; rather, I simply find it cumbersome, and awkward to use. And I'm not keen on its habit of insisting on re-writing itself every time a change is made, though this IS only the way it's designed to work, of course.

I've no problem with Microsoft, or SecureBoot.....or with UEFI. These things exist, they're here to stay, and the best thing we can do is to learn to work with them, rather than constantly moaning about them. SecureBoot, especially, is simply a 'facet' of the UEFI specifications.....and, unlike many people seem to think, is NOT controlled by Microsoft. After all, it was only ever intended to make booting more secure, irrespective of the OS in use; that's the bit many fail to comprehend.

Granted, this overview IS several years old, and from the earlier days of the standard's implementation. But despite that a lot has changed, it still presents the salient points in a clear, easy-to-understand manner. I felt it would be informative, and of use to the community. It's certainly clarified a lot of points for ME.

@rockedge :-

Ooh! You're showing your age, Erik!

Mike.

[rcrsn51]

As for GRUB2, ... I'm not keen on its habit of insisting on re-writing itself every time a change is made, though this IS only the way it's designed to work, of course.

Explain please.

[mikewalsh]

As for GRUB2, ... I'm not keen on its habit of insisting on re-writing itself every time a change is made, though this IS only the way it's designed to work, of course.

Explain please.

I may be wrong, but do you not have to run

Code: Select all

update-grub

.....every time changes are made? And does this not force it to rewrite itself?

(If I'm wrong, I'm willing to be corrected. I'm certain it did this in Ubuntu every time a kernel upgrade was installed.....which with Canonical, is often every few days.)

Mike.

[fredx181]

I may be wrong, but do you not have to run

update-grub

.....every time changes are made? And does this not force it to rewrite itself?

On major distro's often it's recommended to use it that way, but not required.
Grub2 can be used very similar way as grub4dos, just edit manually grub.cfg and boot (only the syntax for grub.cfg is a bit different than menu.lst).

[rcrsn51]

.....every time changes are made? And does this not force it to rewrite itself?

Update-grub is the GRUB2 equivalent of running Grub4Dos Bootloader Config. It generates a new boot menu based on the OS's it detects.

[Clarity]

This thread's contents "makes plain" info that many members refused to want to know. It too easy to hate 'new' things when they come along. But, these 2 items brought to light in this thread have been around in industry and linux for DECADES while some members continue reluctance to want to move and to understand new benefits. UEFI firmware is indepentdent of GRUB2 software, but each has benefits that we can manipulate for our use and benefit.

I HOPE, more members using 64bit PCs will try and understand this information shared by some here for our benefit. Yet, for many, there is an emotional barrier that they hold, which limits any desire to understand, falling back on preconceived notions as a basis for resistance to understanding. (Yes, we all have them)

The following, though, are very good points to note/

On major distro's often it's recommended to use it that way, but not required.

Correct in making this info plain.

Update-grub is the GRUB2 equivalent of running Grub4Dos Bootloader Config. It generates a new boot menu based on the OS's it detects.

Correct in making this info plain.

Thanks for this thread's contribution in the forum.

[mikewalsh]

@rcrsn51 / @fredx181 :-

Uh-huh. Fair enough; because I've not touched GRUB2 since my Ubuntu days - and that's nearly 8 yrs ago - I wasn't really aware that manual editing was possible.....though of course, there's no reason why you couldn't.

I never took much notice in those days; I was still early in my Linux journey, and from what I vaguely recall, 'update-grub' was run by the system as a matter of course during update sessions whenever a kernel upgrade was involved. Totally automatic; no user input was required.....I would guess the entire thing was scripted to ensure ease of operation for all users, regardless of ability.

I believe this was due to the fact that Ubuntu didn't just look for 'vmlinuz' like Puppy does, but the kernel package changed the whole kernel version number with every update, so the GRUB2 boot-script had to re-write itself every time.....or else it would never find it. I never did understand why mainstream distros insisted on specifying the full kernel version number every time, when Puppy gets away with specifying just one word. It avoids the need to re-write the bootloader with every upgrade.

It's always seemed to me that it's unnecessarily generating extra work purely for the sake of it. I'm sorry to say, no amount of explanations of GRUB2's operation will ever really make me like it......no matter how "efficient" it may in fact be.

Just my personal viewpoint, which should in no way appear to discourage others from becoming familiar with it. Since I'm all-Puppy, Grub4DOS works for me, the way I currently implement the boot stanzas. I'm content with it. If it becomes necessary for me to become au-fait with other bootloaders, I shall do so as & when needed.

(*shrug*)

Mike.

[Marv]

Thanks for posting that link Mike, it helped me with my understanding of UEFI. As of now, all of my hardware -and there's a bit of it- has BIOS as the inbuilt firmware. At some point if I outlive my stash of hardware I will have to boot from a box or lappie with UEFI firmware so I try to learn enough now -and stay agnostic- to ease both future hardware selection and that boot process a bit.