On 12/21/2017 05:13 PM, Felix Miata wrote:
[...] It's not so easy to figure out when POST is over with UEFI. Here, it seems efibootmgr -t provides extra delay beyond what the BIOS defines for you to make a selection from its own boot device selection menu, which requires an F12 keystroke here to see. The timeout after appearance of Grub's menu is supposed to be controlled by /etc/default/grub's GRUB_TIMEOUT=, which shows up here in Stretch's grub.cfg first on line 86, a few lines before "### END /etc/grub.d/00_header ###".
Edited /etc/default/grub to change GRUB_TIMEOUT to 11:
root@BR914:/etc/default# nano grub
Observed "If you change this file, run 'update-grub' afterwards..." :
root@BR914:/etc/default# update-grub
Generating grub configuration file ...
Found background image: /usr/share/images/desktop-base/desktop-grub.png
Found linux image: /boot/vmlinuz-3.16.0-4-amd64
Found initrd image: /boot/initrd.img-3.16.0-4-amd64
Found Debian GNU/Linux (9.3) on /dev/mapper/vol2-root
Found Debian GNU/Linux (buster/sid) on /dev/mapper/vol3-root
done
Looking at /boot/grub/grub.cfg, timeout is mentioned as follows:
if [ "${recordfail}" = 1 ] ; then
set timeout=-1
else
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=menu
set timeout=11
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
set timeout=11
fi
fi
...but there is no effect. The timeout when rebooting is still 3
seconds. I'm no shell expert so I don't know how to interpret the above.