grub归档 - KB记录与收集站

Grub2多种引导教程

2021年10月9日

手动引导ubuntu的iso镜像文件从而安装ubuntu，grub>代表命令的开始

假设ubuntu镜像在U盘的第一个分区的根目录下即：(hd0,1)/ubuntu-18.04-desktop-amd64.iso

手动引导下可以按TAB键补全命令、目录以及文件名

#查询所有已安装磁盘并打印详细信息
grub>ls -l

 #设置根目录分区
grub>set root=(hd0,1)

#将Ubuntu.iso位置赋值给变量isofile （这里用变量方便下面不用打一长串文件名）
grub>set isofile=/ubuntu-18.04-desktop-amd64.iso

#使用grub2的回放技术，把ubuntu.iso的文件内容，投射（挂载）到loop上。在使用这个命令时，你得考虑你的内存足够的大。(hd0,1)iso镜像文件所在分区
grub>loopback loop (hd0,1)$isofile

#加载内核，其中(loop),是使用了上一句所投射的设备，其访问的是ubuntu.iso文件的内容，boor=casper将目录casper挂载为boot，iso-scan/filename=$isofile 是利用iso-scan来寻找到你的ubuntu.iso文件所在位置并把所找到的iso文件挂到光驱设备
grub>linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile quiet splash

#initrid.lz是一个镜象文件，里面存的是一些内核要加载的重要文件
grub>initrd (loop)/casper/initrd.lz

#根据上面的参数启动系统
grub>boot

手动引导archlinux的iso镜像文件从而安装archlinux，grub>代表命令的开始

假设archlinux镜像在U盘的第一个分区的根目录下即：(hd0,1)/archlinux-2018.07.01-x86_64.iso

grub>set root=(hd0,1)
grub>set isofile=/archlinux-2018.07.01-x86_64.iso
grub>loopback loop (hd0,1)$isofile
 #img_dev=/dev/sda1 镜像文件所在分区设备，如果不清楚所在设备是怎么排序的可以使用img_dev=/dev/disk/by-uuid/分区的UUID 关于UUID可以用"grub>ls -l" 指令查询,或者可以用img_dev=/dev/disk/by-labe/分区卷标 
grub>linux (loop)/arch/boot/x86_64/vmlinuz img_dev=/dev/sda1 img_loop=$isofile earlymodules=loop
grub>initrd (loop)/arch/boot/x86_64/archiso.img
grub>boot

或者

grub>set root=(hd0,1)
grub>set isofile=/arch.iso
grub>loopback loop (hd0,1)$isofile
grub>linux (loop)/arch/boot/x86_64/vmlinuz img_loop=$isofile archisobasedir=arch archisolabel=ARCH_XXXXXX #此处为发布年月
grub>initrd (loop)/arch/boot/x86_64/archiso.img

手动引导Ubuntu

假设ubuntu安装在第一块硬盘的第一个分区即：(hd0,1)

grub>root=(hd0,1)
grub>linux /boot/vmlinuz-xxx
grub>initrd /boot/initrd.img-xxx
grub>boot

XXX是内核版本号

关于linux的通用引导方法其实与上面差不多，就是在“grub>linux /boot/vmlinuz-xxx”这一句加载内核的文件与后面跟的参数有所不同，不同的linux发行版会有不同的参数，有些可以也不加参数启动

手动引导uefi启动模式下的Windows。
winPE也可以用此方法引导

假设windows安装在第一块硬盘的第一个分区即：(hd0,1)

#加载ntfs文件系统
grub>insmod ntfs
grub>set root=(hd0,1)
#grub>chainloader +1 是引导传统bios启动的Windows
#如果不成功则可能是efi文件被替换用换个目录试试如：chainloader/EFI/microsoft/boot/bootmgfw.efi
grub>chainloader /EFI/boot/bootx64.efi
grub>boot

手动引导bios启动模式下的Windows。
winPE也可以用此方法引导

假设windows安装在第一块硬盘的第一个分区即：(hd0,1)

chainloader /bootmgr 命令会报签名错误，即使关闭签名验证也无法启动(chainloader +1也可启动系统但不可启动U盘pe)

grub>set root=(hd0,1)
# /bootmgr 是一个在根目录下的引导文件，bootmgr是在Windows Vista、Windows 7、windows 8/8.1和windows 10中使用的新的启动管理器，就相当于Win NT/Win 2000/Win XP时代的NTLDR。
grub>ntldr /bootmgr
grub>boot

原作者：(3条消息) grub2各种手动命令引导教程（引导Ubuntu及安装镜像，arch Linux及安装镜像，Windows及winPE）_worldy_MCX的博客-CSDN博客

Aliyun, Cloud, Linux

Ubuntu does not display GRUB menu solutions

2021年5月28日

To display the GRUB menu, comment GRUB_HIDDEN_TIMEOUT=0 and GRUB_HIDDEN_TIMEOUT_QUIET=true as shown in the image above

The meaning of the above parameters is explained as follows:

GRUB_DEFAULT=0
The GRUB menu item is enabled by default. The specific GRUB items can be found in /boot/grub/grub.cfg

GRUB_HIDDEN_TIMEOUT=0
This configuration will affect the menu display. If this option is set, the menu is hidden for this time and the boot screen is displayed. The menu will be hidden unless you add a # sign at the beginning of the line. (# GRUB_HIDDEN_TIMEOUT = 0). The first time GRUB 2 is executed, it will look for other operating systems. If no other operating system is detected, the menu is configured to be hidden. If other operating systems are recognized, the menu will display. If an integer is greater than 0, the system will pause according to the number of seconds configured, but no menu will be displayed. 0, the menu will not be displayed and there will be no delay. Users can hold down the Shift key at startup to force the menu to appear. During startup, the SHIFT key status is checked. If the keystroke status is not recognized, there is a short delay to allow the user to display the menu by pressing the Esc key.

GRUB_HIDDEN_TIMEOUT_QUIET=true
True does not display a countdown. The screen will be blank. False The time configured in GRUB_HIDDEN_TIMEOUT. There will be a countdown timer on the blank screen.

GRUB_TIMEOUT=10
This command will comply with the GRUB_HIDDEN_TIMEOUT configuration unless GRUB_HIDDEN_TIMEOUT is commented out (#). If GRUB_HIDDEN_TIMEOUT is enabled,GRUB_TIMEOUT will only be executed once when the menu is displayed. Configuring this value to -1 will cause the menu to remain displayed until the user selects it. The GRUB 2 menu is hidden by default unless other operating systems are detected by the system. If there is no other operating system, this line will be commented out unless the user modifies it. To display the menu on startup each time, uncomment this line and use a value of 1 or greater.

GRUB_CMDLINE_LINUX_DEFAULT=”splash”
This command is used to set the default startup mode of the system, which can be set as character interface or graphical interface with parameters including quite, splash, text

(1) the meaning of quiet: kernel startup to simplify the prompt message (the prompt message when starting the system, adding this command will simplify the prompt message)

(2) The meaning of splash: the character output process of init is replaced by a graphical progress bar at startup

(3) text meaning: set the system after the character interface, from the character interface to enter the graphical interface can use startx