On Mon, Apr 3, 2017 at 6:19 PM, Konstantin Olchanski <[log in to unmask]> wrote:


> Hi, you may find it easier to do the work using the SYSLINUX/EXTLINUX
> boot loader.
>
> In my experience, it takes less time to learn how to use syslinux from
> zero, compared to doing anything at all non-standard in grub/grub2.

If I don't use grub, I use lilo on BIOS and systemd-boot on EFI. They
have fewer files and complications under "/boot".


> And with grub2 even having custom order of boot entries is now
> non-standard.
>
> This is addition to all the cases where grub/grub2 just plain does not
> work (gives you a blank screen, or tells you that existing files do
> not exist, or goes to the wrong disk, or in one case corrupted the
> CMOS settings, and etc of course).

grub2's quite flexible, unless you want to change the actual
labels/names of the menu entries.

These are the variables that you can set in "/etc/default/grub"

GRUB_ACTUAL_DEFAULT
GRUB_BACKGROUND
GRUB_BADRAM
GRUB_BUTTON_CMOS_ADDRESS
GRUB_BUTTON_CMOS_CLEAN
GRUB_CMDLINE_GNUMACH
GRUB_CMDLINE_LINUX
GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_XEN_REPLACE
GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT
GRUB_CMDLINE_NETBSD
GRUB_CMDLINE_NETBSD_DEFAULT
GRUB_CMDLINE_XEN
GRUB_CMDLINE_XEN_DEFAULT
GRUB_DEFAULT
GRUB_DEFAULT_BUTTON
GRUB_DEVICE
GRUB_DEVICE_BOOT
GRUB_DEVICE_BOOT_UUID
GRUB_DEVICE_UUID
GRUB_DISABLE_LINUX_UUID
GRUB_DISABLE_OS_PROBER
GRUB_DISABLE_RECOVERY
GRUB_DISABLE_SUBMENU
GRUB_DISTRIBUTOR
GRUB_ENABLE_CRYPTODISK
GRUB_FONT
GRUB_FS
GRUB_GFXMODE
GRUB_GFXPAYLOAD_LINUX
GRUB_HIDDEN_TIMEOUT
GRUB_HIDDEN_TIMEOUT_BUTTON
GRUB_HIDDEN_TIMEOUT_QUIET
GRUB_INIT_TUNE
GRUB_OS_PROBER_SKIP_LIST
GRUB_PRELOAD_MODULES
GRUB_RECORDFAIL_TIMEOUT
GRUB_RECOVERY_TITLE
GRUB_SAVEDEFAULT
GRUB_SERIAL_COMMAND
GRUB_TERMINAL_INPUT
GRUB_TERMINAL_OUTPUT
GRUB_THEME
GRUB_TIMEOUT
GRUB_TIMEOUT_BUTTON
GRUB_TIMEOUT_STYLE
GRUB_TIMEOUT_STYLE_BUTTON
GRUB_VIDEO_BACKEND

I have a Debian testing VM where I've run "chmod -x /etc/grub.d/*" and
created the following "/etc/grub.d/90-grub":

#!/bin/sh

cat <<EOF
# menu
set default=0
set timeout=2

# kernel
insmod gzio

# disk/partition
insmod part_msdos

# filesystem
insmod ext2

# /boot
search --no-floppy --fs-uuid --set=root c6c45a21-9b93-4575-aa11-2011da070d4d

# video
terminal_input console
terminal_output console

menuentry 'stretch' {
linux /kernel root=UUID=5d16e6e7-19d3-4cc1-ad06-394a4d343fcf ro
initrd /ramfs
}

menuentry 'stretch (systemd)' {
linux /kernel root=UUID=5d16e6e7-19d3-4cc1-ad06-394a4d343fcf ro
init=/lib/systemd/systemd
initrd /ramfs
}

menuentry 'stretch (single)' {
linux /kernel root=UUID=5d16e6e7-19d3-4cc1-ad06-394a4d343fcf ro single
initrd /ramfs
}

menuentry 'stretch (runit)' {
linux /kernel root=UUID=5d16e6e7-19d3-4cc1-ad06-394a4d343fcf ro
init=/usr/local/bin/init-runit
initrd /ramfs
}

menuentry 'stretch (script)' {
linux /kernel root=UUID=5d16e6e7-19d3-4cc1-ad06-394a4d343fcf ro
init=/usr/local/bin/init-script
initrd /ramfs
}
EOF