[arch-general] [arch-releng] Default Bootloader for AIF

[Dieter Plaetinck]

On Sun, 27 Mar 2011 13:17:02 +0530
"KESHAV P.R." <skodabenz at gmail.com> wrote:

> Hi all,
>          I wanted to share my views on this whole discussion. Many
> people don't know the actual features and problems with individual
> boot-loaders.
> 
> GRUB-Legacy
> 
> - Kinda KISS (actually syslinux is more KISS)
> - Easy to setup and configure
> - Simple config file - text file based
> - Multi-partition support (can load kernels from diff partitions -
> multi-linux systems)
> - Supported by AIF and Archboot
> 
> X Does not support newer filesystems like BTRFS, NILFS2 etc.
> X No GPT and non-MBR partition tables support
> X No LVM, RAID etc.. (I may be wrong here)
> X No jpeg, png images support (not that it matters for arch users -
> mainly for users wanting eye-candy stuff)
> X No partition search support, needs hardcoding partition number in grub.conf
> X Supports only BIOS and MBR systems
> X Upstream deprecated
> X Difficult to maintain patches
> X The only fork of grub-legacy (Fedora's -
> http://git.kernel.org/?p=boot/grub-fedora/grub-fedora.git) (Arch does
> not use this) is also planning to stop development -
> http://fedoraproject.org/wiki/Features/Grub2#Benefit_to_Fedora
> 
> 
> GRUB2 (will be grub according to upstream once released as stable)
> 
> - Modules support
> - Virtually all open source filesystems and few proprietary ones like ntfs, hfs
> - All-in-one bootloader
> - Setting up is actually easy - just lack of docs for that
> - All eye-candy stuff
> - Almost all partitioning systems - you can even use Archlinux in
> Amiga partitioning or Apple Partition Map with grub2
> - loopback support for booting isos
> - Maintained by upstream
> - LVM, RAID and other stuff supported
> - Supports partition searching at runtime (using search command)
> - UUID support (with search)
> - Multiple firmwares support (independent of partitioning scheme) like
> Coreboot, UEFI etc.
> - Scripting support in grub.cfg with env variables etc. , useful for
> some users (for me atleast).
> - Configuration can be edited directly (its a common misconception
> regarding uneditable grub.cfg)
> - Rescue mode
> - Can manually load grub-legacy config file and supports converting
> from grub.conf (or menu.lst) to grub.cfg format - grub-menulst2cfg in
> grub2-common package
> 
> BTRFS support in the works. Its actually completed but there are few
> issues with copyright (with Oracle) and licensing issues (BTRFS is
> GPL2 , GRUB2 is GPL3, both are not GPL2+) so its not there in release
> versions and bzr trunk right now.
> 
> X Not KISS
> X Takes more steps (!=complex) to setup
> X Configuration may be difficult to understand (its basically a shell
> script like language rather than simple text based)
> X Requires dedicated space for embedding core.img (first 32KB in case
> of MBR or BIOS Boot partition in case of GPT)
> X Lack of proper and complete documentation - This is the main reason
> for users abandoning grub2 (it is NOT complex to setup, simply more
> steps)
> X Not yet stable
> 
> The funny thing is grub-legacy is regarded as stable when it was
> actually designated as alpha by upstream (not even beta, it never
> reaches 1.00 version) so I think grub2 can be used in place of
> grub-legacy.
> 
> 
> SYSLINUX
> 
> - KISS
> - Actively maintained
> - GPT, MBR and unpartitioned (whole disk) (not other partitioning systems)
> - Easy to setup
> - Kinda modular (though not to the extent of grub2)
> - LVM (RAID?)
> - png., jpeg etc
> - Simple config file
> - ISO bootloading apart from HDD
> - NO dedicated embedding space
> - Supported by AIF and Archboot
> 
> X No multi-partition multi-OS systems support (loading kernels
> directly) (not chainload)
> X No rescue mode (I had an experience with this -
> http://syslinux.zytor.com/archives/2010-December/015875.html)
> X Few filesystems spported - no reiserfs, xfs etc.
> X No UEFI or other firmware support
> 
> I personally like grub2 (but testing syslinux right now just for fun -
> in GPT, not in MBR). These views are my own and not of the upstream
> devs or arch devs. In any case grub-legacy should be deprecated since
> it is difficult to maintain according to pressh and there is no plan
> to switch to fedora maintained fork since that may also go off once
> fedora implements grub2 in its installer (Anaconda).
> 
> I propose shifting completely to syslinux including automatic
> installer. On a side note, I think it is also useful to have GPT
> partitioning as default now since it is way superior to MBR (see
> logical partitions linked-list info) and supports multiple primary
> partitions. Please free to provide any comments regarding my views and
> finally sorry for such a long mail. We can take this discussion to the
> forum if needed.
> 
> Regards.
> 
> Keshav

Hi Keshav, thanks for this overview.

My notes:
- grub-legacy is tricky to setup (from an aif POV, not from a user POV)
- I accept patches for grub2 if they are reasonably sane/elegant

From your overview, as well as Pierres first thread (and the responses to that), it seems all 3 bootloaders have something about them that makes them more suited for specific use cases, and less so for other cases. So none is clearly superior or inferior then the others, it all depends on the circumstances.

So, for the AIF perspective, I would say "which should be the default?" is an irrelevant question, the important thing is, we support two (and later maybe 3) and the user can choose.

So, maybe this is a question that should be answered by the package maintainers: because the order in which we list bootloader selection (i.e. which is at the top, the "default") will probably steer -to some extent- package usage and bug reports; which bootloader do you feel most comfortable with maintaining?
The answer is very likely syslinux. Allan, Thomas, other maintainers/developers?

Dieter