RedHat Wants to Give Bootloaders the Boot and Replace Them with nmbl

raindog308

RedHat's mission statement is to "reinvent everything in Linux, regardless if it needs reinventing" and to that end, they're working on nmbl ("nimble"), with the goal of ditching GRUB and letting kernels boot directly.

Write Up

davide

With the EFI Boot Stub a regular chroot directory tree can be a bootloader: https://docs.zfsbootmenu.org/en/v2.3.x/

Getting rid of Grub 2 is welcomed from me. I'm still using Grub Legacy on the workstation, because the newer Grub 2 piece of shit is not comprehensible. At all. I cannot read anything out of that clusterfuck of config scripts. The monster who had that clever idea of using dynamically-generated scripts instead of plain config files deserves a spot in Hell next to Poettering.

raindog308

@davide said: because the newer Grub 2 piece of shit is not comprehensible. At all. I cannot read anything out of that clusterfuck of config scripts.The monster who had that clever idea of using dynamically-generated scripts instead of plain config files deserves a spot in Hell next to Poettering.

Who actually configures grub...or even goes into grub...

I've probably installed Linux 200 times over the last year, and maybe 30-40 of that was using the installer. I've never mucked with grub once.

what are you doing that is so hardwareish that you need to fiddle with grub?

lukast__

@raindog308 said:

@davide said: because the newer Grub 2 piece of shit is not comprehensible. At all. I cannot read anything out of that clusterfuck of config scripts.The monster who had that clever idea of using dynamically-generated scripts instead of plain config files deserves a spot in Hell next to Poettering.

Who actually configures grub...or even goes into grub...

I've probably installed Linux 200 times over the last year, and maybe 30-40 of that was using the installer. I've never mucked with grub once.

what are you doing that is so hardwareish that you need to fiddle with grub?

I have previously edited /etc/default/grub to change the kernel cmdline and to remove the 5 second grub menu, both nothing hardwareish, rather booting speed optimizations, but as soon as I have time to finish the kernels make menuconfig, I'll replace grub with https://github.com/wikkyk/mlb which fits in the MBR and simply starts the kernel.

davide

@raindog308:

Setting a console font or a backup kernel requires editing the grub config. Grub Legacy can even automatically boot into a secondary kernel if the primary fails, it uses a sort of watchdog in userspace that registers the successful boot, and reboots into the secondary if the first fails. Grub Legacy can easily boot into runlevel 1 if runlevel 2 fails, or straight to /bin/bash if needed. On the other hand, I have no idea what Grub 2 is, except that it's an incomprehensible clusterfuck.

Exhibit 1:

# cat /boot/grub/menu.lst
default         0
timeout         5
color cyan/blue white/blue

title           6.9.9 amd64 (zfs) - HDD label: "main" (/dev/sd.2)
root            (hd0,1)
kernel          /boot/vmlinuz-6.9.9 root=UUID=b3e7646b-ebf3-4c20-b59f-7436678e21f1 quiet 2
initrd          /boot/initrd.img-6.9.9

title           4.13.2 amd64 - HDD label: "main" (/dev/sd.2)
root            (hd0,1)
kernel          /boot/vmlinuz-4.13.2 root=UUID=b3e7646b-ebf3-4c20-b59f-7436678e21f1 quiet 2
initrd          /boot/initrd.img-4.13.2

That is what Grub Legacy is to me.

Exhibit 2:

That is what Grub 2 is to me.

davide

This discussion was an opportunity to relook into my fucked up bootloader situation. The notebook has an SSD with EXT4, because EXT4 supports the trim command required on SSDs, so Grub Legacy couldn't boot it (it only supports EXT3), and I was unjustly coerced into using Grub 2. But now I just flushed that turd, and married the simple and elegant Syslinux:

# dpkg --get-selections | grep grub
#

she looks beautiful:

and this is her sexy 15-line config file:

# cat /boot/syslinux/syslinux.cfg
DEFAULT menu.c32
TIMEOUT 50
PROMPT 0

LABEL 0
MENU LABEL Debian GNU/Linux, with Linux 5.17.5-5620z-sdcard
KERNEL /boot/vmlinuz-5.17.5-5620z-sdcard
INITRD /boot/initrd.img-5.17.5-5620z-sdcard
APPEND root=/dev/sda1 ro rootflags=noatime,nodiratime,async quiet 2

LABEL 1
MENU LABEL Debian Ext4 ramdisk
KERNEL /boot/vmlinuz-5.17.5-RAM-5620z
INITRD /boot/RAMdebian_ramdiskOK1.img.gz
APPEND root=/dev/sda1 ro rootflags=noatime,nodiratime,async quiet 2

Call me what you want, but fuck grub.

darkimmortal

@davide said:
With the EFI Boot Stub a regular chroot directory tree can be a bootloader: https://docs.zfsbootmenu.org/en/v2.3.x/

Getting rid of Grub 2 is welcomed from me. I'm still using Grub Legacy on the workstation, because the newer Grub 2 piece of shit is not comprehensible. At all. I cannot read anything out of that clusterfuck of config scripts. The monster who had that clever idea of using dynamically-generated scripts instead of plain config files deserves a spot in Hell next to Poettering.

Most of Poettering's creations are good for the same reason you like grub legacy - simple config files rather than arcane layers of scripts

davide

Good, now brush your teeth and go to sleep.

Erisa

@davide said: and this is her sexy 15-line config file:

Comparing this to the grub legacy config you also posted, it seems syslinux can be thought of as the spiritual successor to grub legacy. Didn't know that, will be looking into it next time I muck with boot orders.

jperkins

I'm not opposed to something better but grub2 isnt that hard to customize. modifying /etc/default/grub and update-grub are regular things. tweaking grub and this is something done on every install

sed -i s/MODULES=most/MODULES=dep/ /etc/initramfs-tools/initramfs.conf ;update-initramfs -u

davide

@Erisa said:
it seems syslinux can be thought of as the spiritual successor to grub legacy.

Right, and it works with BIOS/MBR too, which my laptop is stuck with. Upon installation it writes 480 bytes to the disk's MBR and places these files in /boot/syslinux:

ls -lh /boot/syslinux/
total 408K
-r--r--r-- 1 root root 117K Jul 23 21:17 ldlinux.c32
-r--r--r-- 1 root root  58K Jul 23 21:17 ldlinux.sys
-rw-r--r-- 1 root root 166K Jul 23 22:49 libcom32.c32
-rw-r--r-- 1 root root  23K Jul 23 22:49 libutil.c32
-rw-r--r-- 1 root root  26K Jul 23 22:25 menu.c32
-rw-r--r-- 1 root root  446 Jul 23 22:54 syslinux.cfg

it's crazy small in contrast with EFI bootloaders.