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Fedora considers deprecating legacy BIOS

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Re: Fedora considers deprecating legacy BIOS

#151

Post by bitwize »

tremon wrote: post #17
faho wrote: post #12

Earlier quoted context omitted.

What replacement do you propose, then? Especially what replacement do you propose that works with the kind of typical hardware that non-specialty linux distros like Fedora want to support? Intel systems make up a large chunk of the hardware Fedora is used on, and as far as I can tell they're all-in on EFI. So Fedora has to use EFI to be able to boot on Intel systems.

OpenFirmware: https://en.wikipedia.org/wiki/Open_Firmware Many systems get by just fine with a minimal ELF or multiboot loader and a firmware-provided devicetree specification. Dynamic hardware enumeration is performed by every OS anyway, the only hardware that must be initialized is the bootloader/kernel storage. For the x86 platform, this could be implemented via coreboot (libreboot always reads to me as lib-reboot…

But OEMs didn't choose OpenFirmware. They chose UEFI. Therefore, Linux must support UEFI, and that's where developer effort will go.

Re: Fedora considers deprecating legacy BIOS

#152

Post by bitwize »

BeefWellington wrote: post #125

This is a bit of a tone deaf idea to explore right now. If anything, the environment and chip shortage issues should be pushing people to promise extending support for older systems for another decade. That said, while there are loads of systems out there that could still use BIOS, I like to look at the second hand market. There are a lot of Dell R710s for sale on eBay still (700+ listings). These are commonly sugges…

> Contrasting this, some UEFI implementations are horrifically buggy and largely seem designed to only work with Windows.

UEFI specifications are like Web specifications: they're good to wipe your ass with, but on the Web when the rubber meets the road, the only "standard" that matters is "does it work in Chrome" (in the past, IE). Similarly the only standard that a UEFI implementation need comply with is "does it boot Windows".

Re: Fedora considers deprecating legacy BIOS

#153

Post by bitwize »

jeroenhd wrote: post #92
AshamedCaptain wrote: post #64

Earlier quoted context omitted.

They also do this because it is likely that Microsoft will stop signing their bootloaders/kernels with their UEFI CA keys if they allow arbitrary user modules to be loaded (because it would be trivial to abuse those kernels to break Windows' full disk encryption). And if Microsoft stops signing your bootloaders it is an automatic death sentence for your distribution, as you can no longer boot the LiveCD without "scar…

Secure boot allows you to load your own keys. That's the way some Linux distros actually recommend you to set it up: sign your own bootloader, kernel, kernel modules, everything, and tell your motherboard to trust that. It's arguably even more secure than Microsoft's approach because anyone can boot a Windows install disk, but getting a boot drive with your signature on it requires breaking into your system. This cou…

> There's nothing inherently Microsoft related about secure boot,

Microsoft is the root of trust for ~100% of OEM secure boot implementations.

Theoretically, you can implement Secure Boot with an alternative root of trust... but you'd have to get the OEMs on board... to the tune of many millions of dollars. Per OEM.

The only alternative is to get users to install their own keys, which is fiddly and technical.

Therefore, for all intents and purposes, Linux on the desktop is only a thing at all because Microsoft deigns to allow it for the time being.

Re: Fedora considers deprecating legacy BIOS

#154

Post by tenebrisalietum »

userbinator wrote: post #120

Leave things as they are. Code continues to rot. What is this ever-present BS about "rot"!? Why do people think continual changes are even needed? Code should become more stable over time, an ideal that I wish much more software would follow. The way BIOS boot works has basically remained unchanged ever since the first IBM PC, and it's incredibly simple. Linus Torvald's opinion of EFI is worth reading: https://yarchi…

The intersection point between simple and useful is this:

- Firmware understands some sort of minimal filesystem and how to talk to a device containing it.

- Firmware has a configuration store that holds a few variables and a device tree.

- Firmware has the ability to load binary images into RAM from the minimal filesystem above.

- On boot, configuration is checked, the kernel and initrd are binary-loaded into RAM, and the firmware jumps to the kernel with a pointer to the commandline, initrd, and device tree.

U-Boot more or less does this and it's beautiful. The bootloader loads your OS and then gets out of the way. No multistage crap or overengineered firmware interfaces.

Re: Fedora considers deprecating legacy BIOS

#155

Post by dralley »

sounds wrote: post #131
mjg59 wrote: post #25

Earlier quoted context omitted.

- previously, x86 MBR-style partition tables (which were the only thing really supported in Linux) gave you no strong semantic information about what a partition was[1]. GPT may involve GUIDs, but in the grand scheme of things that's a small part of the cost of mounting stuff. - FAT is old, and FAT is well-supported by basically anything, and what features do you want in the partition that contains your bootloader th…

Quoted post unavailable.

Matthew left Red Hat 10 years ago. If you're going to "full disclosure" people, you should probably do a better job with the details.

Re: Fedora considers deprecating legacy BIOS

#156

Post by probably_wrong »

mustache_kimono wrote: post #149
BirAdam wrote: post #99

At a time when the world is producing several hundred million tons of e-waste each year, that this was even entertained is bad. I suppose its fine to make toxic trash mountains in the third world to get rid of a small amount of code bloat?

Anyone who says things like this, should be the ones that have to support the legacy code. They should be sentenced to a 15+ year old computer and to explain to their colleagues how we just can't do anything new, because we need to use GCC 4.7 to build the world because , now used by 20 non-paying users, won't work with anything newer. Fedora is only one, relatively fast moving distro, which gives you their software…

> They should be sentenced to a 15+ year old computer

I bought my computer about 15 years ago, with what at the time was a pretty beefy setup. I still use it for my everyday work because, as it turns out, you don't need much more than 4Gb of RAM to surf the internet.

Due to buggy UEFI support, I cannot reinstall Windows 10 on that PC. If Linux stopped supporting Bios, I'd have to throw it away. But more importantly, this computer has better performance than the computers of many of my relatives in South America.

I wish every developer in the first world had to explain at least once to their nieces that no, Roblox will not work on their Chinese Android tablet with 1Gb of RAM.

Re: Fedora considers deprecating legacy BIOS

#158

Post by kevinoid »

Perhaps this is a good time to ask: I'd like to use UEFI for my qemu+libvirt virtual machines, but I need snapshot support. Since QEMU doesn't support pflash internal snapshots https://gitlab.com/libvirt/libvirt/-/commit/9e2465834f4bff40...> and libvirt can't revert or delete external snapshots https://bugzilla.redhat.com/show_bug.cgi?id=1519002>, I don't see a way to achieve this. The issue was discussed on virt-tools in 2017 https://listman.redhat.com/archives/virt-tools-list/2017-Sep...> and the situation appears to be unchanged. Do others have a workable solution?

Re: Fedora considers deprecating legacy BIOS

#159

Post by asveikau »

chasil wrote: post #90
zozbot234 wrote: post #48

Earlier quoted context omitted.

> previously, x86 MBR-style partition tables (which were the only thing really supported in Linux) gave you no strong semantic information about what a partition was[1] LVM appears to solve this issue as well as the related issue of only supporting a limited number of partitions in BIOS.

I believe that btrfs can be whole-disk and avoid partitions entirely, which would drastically simplify things. The only snag is swap, which I don't believe can be on a subvolume. vgchange is a struggle for me, from the first time I saw it in HP-UX.

> The only snag is swap, which I don't believe can be on a subvolume.

Linux can make swap a regular file, even. It doesn't need to be a partition.

Google result shows: https://wiki.archlinux.org/title/swap#Swap_file

Re: Fedora considers deprecating legacy BIOS

#160

Post by jeffbee »

superkuh wrote: post #108
mjg59 wrote: post #31

My short summary of this: pretty much every x86 client system since 2012 has shipped with working UEFI support (because Microsoft required it for new Windows 8 systems), and from a compatibility perspective Linux works Just Fine with basically all of them. Servers took a little longer (HP, especially, wanted to do things like just add GPT support to their BIOS implementation), but even that's in a good position now.…

You (and they) forget the part where graphics cards play an intimate role in MBR or UEFI boot. And there still innumberable quite functional graphics cards that will never, ever, allow a system to boot under UEFI. GPUs are deeply integrated into the boot up process. This is easy for IBM/Fedora to forget because GPUs probably don't matter much to them. They just take their intel integrated graphics on their workstatio…

I have a UEFI system right here under my desk that provides legacy BIOS services for running option ROMs, video cards, SCSI host bus adapters, network adapters, anything. It even scans out their legacy video outputs in a little window. There's nothing incompatible between UEFI and legacy option ROMs. Perhaps you are thinking of Secure Boot.
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