Ubuntu boot fix and time adjustment

? Originally for the WIN10 + Ubuntu dual system, using GRUB2 as a guide, in the reload of the WIN10 (the masterpiece died up to 1803) after the system rewrite the boot, can't find Ubuntu, even the BIOS of the startup items are missing, need to repair.

Reference 50589667

Install an Ubuntu installation USB drive, boot from USB stick, try Ubuntu without installing, enter later try to connect (800 * 600 default resolution Mega hard operation)

Open the terminal, a meal operation

$sudo su--Enter password #add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get  update-- Various OK #apt-get install-y boot-repair && boot-repair--various OK

See the window below, click Recommended Repair, or enter #recommended repair in the terminal,

　　

Repair completed, reboot will be able to select the startup project with GRUB2 interface

? Time synchronization, to the effect that Windows sees the BIOS time as the local time, and Linux as a UTC time (and then the region offset), in the reference answer in Windows fixed, but also in Ubuntu fixed, I used the latter.

Reference: Https://www.zhihu.com/question/46525639?sort=created (multiple methods), https://zhuanlan.zhihu.com/p/24762788 (summed up Ubuntu16 previously modified RcS method and Ubuntu16 after the following method)

$sudo su--Enter password #apt-get--localtime--SYSTOHC

? Boot item adjustment (sequential, default, wait time)

Reference 44353499 (Detailed grub parameter meaning), https://www.ssdax.com/2347.html (Serious modification Reference)

Mainly involved in adjusting file/etc/default/grub and file/etc/grub.d/25_custom, file boot/grub/grub.cfg is made up of file files/etc/default/grub and directories/etc/grub.d/ Files automatically generated, once the update-grub will be refreshed, changed the useless

The main part of the/etc/default/grub was changed to:

grub_default=2# Default startup item number, from0Start, my first2Item is windows#grub_hidden_timeout=1# Hide the countdown on a single system, and do not use Grub_hidden_timeout_quiet when commented out=true# don't know Grub_timeout=0# countdown, less than equals zero infinite wait grub_distributor= ' Lsb_release-i-S2>/dev/NULL||echo Debian ' Grub_cmdline_linux_default="Quiet Splash"Grub_cmdline_linux="Acpi_backlight=vendor"

All boot modules are commented out in/etc/grub.d/25_custom (important Ubuntu,ubuntu Advanced and Windows boot Manager are not defined here)

#!/bin/shexec Tail-N +3$0#menuentry"Windows UEFI Bootmgfw.efi"{#search--fs-uuid--no-floppy--Set=root 36e1-3f21#chainloader (${root})/efi/microsoft/boot/bootmgfw.efi#} #menuentry"Windows Boot UEFI Loader"{#search--fs-uuid--no-floppy--Set=root 36e1-3f21#chainloader (${root})/efi/boot/bkpbootx64.efi#} #menuentry"Efi/ubuntu/mokmanager.efi"{#search--fs-uuid--no-floppy--Set=root 36e1-3f21#chainloader (${root})/efi/ubuntu/mokmanager.efi#} #menuentry"Efi/efi/boot/bkpbootx64.efi"{#search--fs-uuid--no-floppy--Set=root ae416b9e-c4d4-4094-82ee-673b949938db#chainloader (${root})/efi/efi/boot/bkpbootx64.efi#} #menuentry"Efi/efi/ubuntu/mokmanager.efi"{#search--fs-uuid--no-floppy--Set=root ae416b9e-c4d4-4094-82ee-673b949938db#chainloader (${root})/efi/efi/ubuntu/mokmanager.efi#}

Then remember to Update-grub in the terminal. The UPDATE-GRUB2 command actually points to Update-grub, so the input is equivalent.

Ubuntu boot Fix and time adjustment