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No more boot loader: Please use the kernel instead

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Re: No more boot loader: Please use the kernel instead

#261

Post by prmoustache »

aaronmdjones wrote: post #127
medstrom wrote: post #110

Earlier quoted context omitted.

You're talking about something like ZFS, and I get that they can't just compile it in, but a distro can still ship the module, if I'm not mistaken. ...But to load it at boot time it absolutely must be done through an initramfs. Is that right?

> But to load it at boot time it absolutely must be done through an initramfs. Is that right? Yes, because it cannot be part of the kernel image, or it would be illegal (a violation of the GPL license) to distribute that kernel. Therefore, it must be a module, and that module has to live somewhere and be loaded by something. If root is on ZFS, this must therefore live in an initramfs and be loaded by it so that the i…

The distro could automatize the compilation of the kernel with ZFS on the user machine. In that case no license is violated as the kernel image is not distributed with ZFS.

That would probably make updates a lot less slower than having zfs shipped in an initramfs though.

Re: No more boot loader: Please use the kernel instead

#262

Post by tpoacher »

kasabali wrote: post #259
mjg59 wrote: post #116

A lot of the commentary here is based on misunderstandings of the capabilities and constraints of a UEFI environment and what the actual goals of this project are, and I think miss the mark to a large degree. Lennart's written some more explicit criticism at https://lwn.net/Articles/981149/ and I think that's a much more interesting set of concerns.

> completely useless if you care about Measured Boot I stopped reading there. All these engineers who help build and defend this draconian crap should be forced to used only an iPad for the rest of their lives.

Of all the horrible punishments you could have envisioned, you went full-on "I have no mouth and I must scream" there...

Re: No more boot loader: Please use the kernel instead

#263

Post by ale42 »

8n4vidtmkvmk wrote: post #241
Am4TIfIsER0ppos wrote: post #117

Earlier quoted context omitted.

Grub is the same everywhere. Motherboard bios/uefi is not. It isn't F10 for me.

How many computers are you operating though? Maybe you'll have to reboot a couple times until you figure out the proper key but then you'll know it. And if you forget it, you clearly aren't doing this often enough for it to be a problem either

It really depends on users. Personally... ~100? Servers, clients, dual-boot configurations, lost machines with PXE boot, various brands and BIOS versions, some even still boot in legacy mode because their UEFI support is bad (like PXE boot doesn't work as well as it should, and as well as it does in "BIOS" mode). So having GRUB on basically all these machines, I'm very happy.

If I could do the same with something that is as small in terms of footprint, and is as flexible as GRUB is (we also PXE-boot into GRUB loaded from the network, both in BIOS and UEFI mode), then I'm interested.

Re: No more boot loader: Please use the kernel instead

#264

Post by vrighter »

LH9000 wrote: post #141
pavon wrote: post #94

Earlier quoted context omitted.

I was working on my Dad's Dell laptop this weekend, and no matter how quickly I spammed the correct key (F12 in this case) it would miss it and continue to a full boot about 3/4 times. I never figured out if it is just picky about timing, or if it had different types of reboots where some of them entering BIOS wasn't even an option.

I start tapping as soon as the screen blanks, probably twice a second. I find this to be best for all BIOS/UEFI interfaces.

Mine has a large delay between when the keypress is registered and the menu actually shows up. But, the window for pressing the key itself is quite short. Also, if you spam the key too quickly, it will hang indefinitely instead of entering the menu necessitating a hard-reboot. Good times.

Re: No more boot loader: Please use the kernel instead

#265

Post by mjg59 »

kasabali wrote: post #259
mjg59 wrote: post #116

A lot of the commentary here is based on misunderstandings of the capabilities and constraints of a UEFI environment and what the actual goals of this project are, and I think miss the mark to a large degree. Lennart's written some more explicit criticism at https://lwn.net/Articles/981149/ and I think that's a much more interesting set of concerns.

> completely useless if you care about Measured Boot I stopped reading there. All these engineers who help build and defend this draconian crap should be forced to used only an iPad for the rest of their lives.

Measured boot is, in itself, under user control - you can seal whatever secrets you want to any specific state and they'll only be accessible in that situation. This has obvious benefits in terms of being able to (for instance) tie disk encryption keys to a known boot state and so avoid needing to type in a decryption phrase while still preventing anyone from being able to simply modify your boot process to obtain that secret. The largest risk around this is from remote attestation, and that's simply not something where the infrastructure exists for anyone to implement any kind of user restriction (and also it's trivial to circumvent by simply tying any remote attestation to a TPM that's not present at boot time and so can be programmed as necessary - it's just not good at being useful DRM)

Re: No more boot loader: Please use the kernel instead

#266

Post by ale42 »

ziml77 wrote: post #118
alerighi wrote: post #45

It's something you can do since a lot of years. I used to do so 10 years ago, when I've got the first motherboard with UEFI. But is it useful? It saves a minimal time in the boot sequence, but at what cost? The bootloader (being it grub, or something more simple as systemd-boot) is useful to me for a couple of reasons: - it allows to dual-boot with Windows easily: motherboard boot menu is often not easy to access, yo…

Does Windows not ensure that the UEFI boots back into Windows when it does an auto-reboot for updates? There's a UEFI variable called BootNext which Windows already knows how to use since the advanced startup options must be setting it to allow rebooting directly to the UEFI settings. Given that Windows tries to restore open windows to make it look like it didn't even reboot, I'm surprised they wouldn't make sure tha…

No, it doesn't. Even a sysprepped image of Windows (which thus runs Setup to install drivers and finalize the installation) doesn't change the boot order on UEFI machines. I think just the installer does this when you first install Windows.

Re: No more boot loader: Please use the kernel instead

#267

Post by prmoustache »

linsomniac wrote: post #92
ta8645 wrote: post #7

Earlier quoted context omitted.

The Linux kernel does not require an initramfs. You can build a kernel with everything compiled in; with no modules needed at all. Initramfs is used for generic kernels where you don't know beforehand which features will be required. This allows you to avoid wasting RAM on features you don't use. But it is optional.

Is anyone really wanting to get back into the business of building their own kernels? I started using Linux heavily in '92, and I've built a lot of kernels, and am quite happy to not be building them anymore.

kernel compilation is easily automated. I don't want to do that and like the initramfs approach mostly because I like the fact I can take a hard drive out of a computer and boot the system on another one in case of a hardware failure.

That is a lot faster than recovering from a backup.

Re: No more boot loader: Please use the kernel instead

#268

Post by ale42 »

See also this project: https://github.com/zhovner/OneFileLinux

Not a bootloader, but a single-file, very light Linux image that can be loaded directly as an .EFI file. Not useful as an actual OS for daily use, but can have specialized uses (I used it to network boot a whole room of PCs to a Linux showing a slideshow on the framebuffer).

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