grub制作USB启动盘

一、使用 GParted 分区U盘：

第一个分区 500M , 并且设置标识 boot esp , fat32格式
第二个分区剩余全部，ntfs格式（可以读写大于4G的文件）

终端输入命令fdisk -l 查看结果：

终端输入命令blkid 查看结果：

二、扇区末尾1M空间使用命令 `gdisk` 打上标记 `bios_grub` ,格式化方式——`未格式化`

wmx@wmx-ubuntu:~$ sudo gdisk /dev/sdb                                    <=========== 1步骤
[sudo] wmx 的密码：
GPT fdisk (gdisk) version 1.0.1Partition table scan:MBR: protectiveBSD: not presentAPM: not presentGPT: presentFound valid GPT with protective MBR; using GPT.Command (? for help): n                                                 <=========== 2步骤
Partition number (3-128, default 3):                                  <=========== 3步骤 ,回车
First sector (34-30605278, default = 30603264) or {+-}size{KMGTP}:        <=========== 回车
Last sector (30603264-30605278, default = 30605278) or {+-}size{KMGTP}: <=========== 回车
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): EF02                    <=========== 4步骤
Changed type of partition to 'BIOS boot partition'Command (? for help): p                                                    <=========== 5步骤
Disk /dev/sdb: 30605312 sectors, 14.6 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 961A84D4-79FF-47F1-990A-885ED8AD66AE
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 30605278
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)Number  Start (sector)    End (sector)  Size       Code  Name1            2048         1026047   500.0 MiB   EF00  2         1026048        30603263   14.1 GiB    0700  3        30603264        30605278   1007.5 KiB  EF02  BIOS boot partitionCommand (? for help): w                                                    <=========== 6步骤 Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!Do you want to proceed? (Y/N): y                                      <=========== 7步骤
OK; writing new GUID partition table (GPT) to /dev/sdb.
The operation has completed successfully.

使用GParted查看结果

boot esp 标记支持 EFI 启动
bios_grub 标记支持 BIOS 启动

三、安装grub到U盘

1 挂载U盘分区 /dev/sdb1 到 /mnt:
sudo mount /dev/sdb1 /mnt

2 grub安装到MBR
sudo grub-install --target=i386-pc --recheck --boot-directory=/mnt/boot /dev/sdb

3 grub安装到ESP,特别注意--removable参数，安装到移动设备上一定要用这个参数
sudo grub-install --target x86_64-efi --efi-directory /mnt --boot-directory=/mnt/boot --removable

特别注意:

Ubuntu的grub默认的target是i386-pc，这个target包含在grub-pc这个包，如果你的系统使用BIOS+MBR安装，这个包默认是存在的。x86_64-efi这个target包含在grub-efi这个包，只有你的系统使用UEFI+GPT方式安装这个包才会存在。如果某个target报错，错误信息类似于grub-install: error: /usr/lib/grub/x86_64-efi/modinfo.sh doesn’t exist. Please specify --target or --directory. 这样的话，就需要安装grub-pc或grub-efi之后再试。
安装到ESP要加–removable这个参数这个参数专门针对于可移动设备，一定要加
bios_grub标记的分区如果按照上面的分区过程操作了，增加了这个标记的分区，安装grub的时候会自动识别这个标记的分区并成功安装grub，否则报错:

Installing for i386-pc platform.
grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
grub-install: warning: 无法嵌入。在此次安装中 GRUB 只能通过使用块列表安装。但是块列表是不可信赖的，不推荐使用。.
grub-install：错误： will not proceed with blocklists.

四、添加grub菜单

sudo grub-mkconfig -o /mnt/boot/grub/grub.cfg
然后基于你自己的电脑和U盘修改 /mnt/boot/grub/grub.cfg
如下是我的示例：

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#### BEGIN /etc/grub.d/00_header ###if [ -s $prefix/grubenv ]; thenset have_grubenv=trueload_env
fiif [ "${next_entry}" ] ; thenset default="${next_entry}"set next_entry=save_env next_entryset boot_once=true
elseset default="0"
fiif [ x"${feature_menuentry_id}" = xy ]; thenmenuentry_id_option="--id"
elsemenuentry_id_option=""
fiexport menuentry_id_optionif [ "${prev_saved_entry}" ]; thenset saved_entry="${prev_saved_entry}"save_env saved_entryset prev_saved_entry=save_env prev_saved_entryset boot_once=true
fifunction savedefault {if [ -z "${boot_once}" ]; thensaved_entry="${chosen}"save_env saved_entryfi
}###记录错误
function recordfail {set recordfail=1if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}### 加载显示模块
function load_video {if [ x$feature_all_video_module = xy ]; theninsmod all_videoelseinsmod efi_gopinsmod efi_ugainsmod ieee1275_fbinsmod vbeinsmod vgainsmod video_bochsinsmod video_cirrusfi
}### 查找字体
if [ x$feature_default_font_path = xy ] ; thenfont=unicode
else
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4  7195511a-452c-42f9-82d1-e6806399e90f
elsesearch --no-floppy --fs-uuid --set=root 7195511a-452c-42f9-82d1-e6806399e90f
fifont="/usr/share/grub/unicode.pf2"
fi### 加载字体
if loadfont $font ; thenset gfxmode=autoload_videoinsmod gfxtermset locale_dir=$prefix/localeset lang=zh_CNinsmod gettext
fi### 输出显示
terminal_output gfxterm### 设置超时显示
if [ "${recordfail}" = 1 ] ; thenset timeout=30
elseif [ x$feature_timeout_style = xy ] ; thenset timeout_style=menuset timeout=10# Fallback normal timeout code in case the timeout_style feature is# unavailable.elseset timeout=10fi
fi### END /etc/grub.d/00_header ###### 设置菜单外观
### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
if background_color 44,0,30,0; thenclear
fi
### END /etc/grub.d/05_debian_theme ###### BEGIN /etc/grub.d/10_linux ######设置分辨率
function gfxmode {set gfxpayload="${1}"if [ "${1}" = "keep" ]; thenset vt_handoff=vt.handoff=7elseset vt_handoff=fi
}### 根据配置，导出显示模式
if [ "${recordfail}" != 1 ]; thenif [ -e ${prefix}/gfxblacklist.txt ]; thenif hwmatch ${prefix}/gfxblacklist.txt 3; thenif [ ${match} = 0 ]; thenset linux_gfx_mode=keepelseset linux_gfx_mode=textfielseset linux_gfx_mode=textfielseset linux_gfx_mode=keepfi
elseset linux_gfx_mode=text
fiexport linux_gfx_modemenuentry 'Ubuntu 16.04 boot from usb' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-7195511a-452c-42f9-82d1-e6806399e90f' {### 记录错误recordfail### 加载显示驱动load_video### 配置显示模式gfxmode $linux_gfx_mode###insmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi### 加载文件系统支持insmod part_gptinsmod ext2### 设置 /boot 位置set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1fi### 加载内核 ，指定root(根位置 / )linux    /vmlinuz-4.15.0-50-generic root=UUID=7195511a-452c-42f9-82d1-e6806399e90f ro  quiet splash $vt_handoff### 初始化 RAMinitrd /initrd.img-4.15.0-50-generic
}submenu 'Ubuntu 高级选项' $menuentry_id_option 'gnulinux-advanced-7195511a-452c-42f9-82d1-e6806399e90f' {menuentry 'Ubuntu，Linux 4.15.0-50-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.15.0-50-generic-advanced-7195511a-452c-42f9-82d1-e6806399e90f' {recordfailload_videogfxmode $linux_gfx_modeinsmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fiinsmod part_gptinsmod ext2set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1fiecho    '载入 Linux 4.15.0-50-generic ...'linux /vmlinuz-4.15.0-50-generic root=UUID=7195511a-452c-42f9-82d1-e6806399e90f ro  quiet splash $vt_handoffecho   '载入初始化内存盘...'initrd   /initrd.img-4.15.0-50-generic}menuentry 'Ubuntu, with Linux 4.15.0-50-generic (upstart)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.15.0-50-generic-init-upstart-7195511a-452c-42f9-82d1-e6806399e90f' {recordfailload_videogfxmode $linux_gfx_modeinsmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fiinsmod part_gptinsmod ext2set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1fiecho  '载入 Linux 4.15.0-50-generic ...'linux /vmlinuz-4.15.0-50-generic root=UUID=7195511a-452c-42f9-82d1-e6806399e90f ro  quiet splash $vt_handoff init=/sbin/upstartecho    '载入初始化内存盘...'initrd   /initrd.img-4.15.0-50-generic}menuentry 'Ubuntu, with Linux 4.15.0-50-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.15.0-50-generic-recovery-7195511a-452c-42f9-82d1-e6806399e90f' {recordfailload_videoinsmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fiinsmod part_gptinsmod ext2set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1fiecho   '载入 Linux 4.15.0-50-generic ...'linux /vmlinuz-4.15.0-50-generic root=UUID=7195511a-452c-42f9-82d1-e6806399e90f ro recovery nomodeset echo '载入初始化内存盘...'initrd   /initrd.img-4.15.0-50-generic}}### END /etc/grub.d/10_linux ###### BEGIN /etc/grub.d/20_linux_xen ###### END /etc/grub.d/20_linux_xen ###### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry 'Memory test (memtest86+)' {insmod part_gptinsmod ext2set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1fiknetbsd   /memtest86+.elf
}
menuentry 'Memory test (memtest86+, serial console 115200)' {insmod part_gptinsmod ext2set root='hd0,gpt2'if [ x$feature_platform_search_hint = xy ]; thensearch --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  936d36cb-f60a-4f19-a357-ca02dd506de1elsesearch --no-floppy --fs-uuid --set=root 936d36cb-f60a-4f19-a357-ca02dd506de1filinux16    /memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.###
menuentry "usb ubuntu.iso" {recordfailload_videogfxmode $linux_gfx_modeinsmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fiinsmod part_gptinsmod ext2search --no-floppy --fs-uuid --set=root 14993B1124BAFEAAloopback loop ($root)/ubuntu.isoecho    '载入 vmlinuz ubuntu.iso ...'linux  (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=($root)/ubuntu.iso noeject noprompt quiet splash locale=zh_CN.UTF-8echo  '载入初始化内存盘...'initrd (loop)/casper/initrd.lz
}menuentry "USB Try Ubuntu without installing" {### 记录错误recordfail### 加载显示驱动load_video### 配置显示模式gfxmode $linux_gfx_mode###insmod gzioif [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi### 加载文件系统支持insmod part_gptinsmod ext2search --no-floppy --fs-uuid --set=root 14993B1124BAFEAAset gfxpayload=keeplinux    ($root)/casper/vmlinuz.efi  file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash ---initrd    ($root)/casper/initrd.lz
}###### END /etc/grub.d/40_custom ###### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; thensource ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; thensource $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

五、提取ubuntu16.04lts.iso 镜像到 /dev/sdb2

然后重启电脑，选择U盘启动，大功告成