注：以centos7livecd为例
1. 目录结构
[root@santiagod ~]# tree /mnt /mnt ├── EFI │ └── BOOT │ ├── BOOTX64.efi │ ├── fonts │ │ └── unicode.pf2 │ ├── grub.cfg │ └── grubx64.efi ├── isolinux │ ├── boot.cat │ ├── efiboot.img │ ├── initrd0.img │ ├── isolinux.bin │ ├── isolinux.cfg │ ├── macboot.img │ ├── vesamenu.c32 │ └── vmlinuz0 └── LiveOS └── squashfs.img 5 directories, 13 files
2. legacy/bios: isolinux.cfg
[root@santiagod ~]# cat /mnt/isolinux/isolinux.cfg default vesamenu.c32 timeout 100 menu background menu autoboot Starting CentOS Linux 7 in # second{,s}. Press any key to interrupt. menu clear menu title CentOS Linux 7 menu vshift 8 menu rows 18 menu margin 8 #menu hidden menu helpmsgrow 15 menu tabmsgrow 13 menu color border * #00000000 #00000000 none menu color sel 0 #ffffffff #00000000 none menu color title 0 #ff7ba3d0 #00000000 none menu color tabmsg 0 #ff3a6496 #00000000 none menu color unsel 0 #84b8ffff #00000000 none menu color hotsel 0 #84b8ffff #00000000 none menu color hotkey 0 #ffffffff #00000000 none menu color help 0 #ffffffff #00000000 none menu color scrollbar 0 #ffffffff #ff355594 none menu color timeout 0 #ffffffff #00000000 none menu color timeout_msg 0 #ffffffff #00000000 none menu color cmdmark 0 #84b8ffff #00000000 none menu color cmdline 0 #ffffffff #00000000 none menu tabmsg Press Tab for full configuration options on menu items. menu separator menu separator label linux0 menu label ^Start CentOS Linux 7 Live kernel vmlinuz0 append initrd=initrd0.img root=live:CDLABEL=CentOS-7-livecd-x86_64 rootfstype=auto ro rd.live.image quiet rhgb rd.luks=0 rd.md=0 rd.dm=0 menu default menu separator menu begin ^Troubleshooting menu title Troubleshooting label basic0 menu label Start CentOS Linux 7 Live in ^basic graphics mode. kernel vmlinuz0 append initrd=initrd0.img root=live:CDLABEL=CentOS-7-livecd-x86_64 rootfstype=auto ro rd.live.image quiet rhgb rd.luks=0 rd.md=0 rd.dm=0 nomodeset text help Try this option out if you're having trouble starting. endtext label check0 menu label ^Test this media & start CentOS Linux 7 Live kernel vmlinuz0 append initrd=initrd0.img root=live:CDLABEL=CentOS-7-livecd-x86_64 rootfstype=auto ro rd.live.image quiet rhgb rd.luks=0 rd.md=0 rd.dm=0 rd.live.check menu separator label local menu label Boot from ^local drive localboot 0xffff menu separator label returntomain menu label Return to ^main menu. menu exit menu end
3. uefi/efi:grub.cfg
[root@santiagod ~]# cat /mnt/EFI/BOOT/grub.cfg set default="1" function load_video { insmod efi_gop insmod efi_uga insmod video_bochs insmod video_cirrus insmod all_video } load_video set gfxpayload=keep insmod gzio insmod part_gpt insmod ext2 set timeout=10 ### END /etc/grub.d/00_header ### search --no-floppy --set=root -l 'CentOS-7-livecd-x86_64' ### BEGIN /etc/grub.d/10_linux ### menuentry 'Start CentOS Linux 7 Live' --class fedora --class gnu-linux --class gnu --class os { linuxefi /isolinux/vmlinuz0 root=live:LABEL=CentOS-7-livecd-x86_64 ro rd.live.image quiet rhgb initrdefi /isolinux/initrd0.img } menuentry 'Test this media & start CentOS Linux 7 Live' --class fedora --class gnu-linux --class gnu --class os { linuxefi /isolinux/vmlinuz0 root=live:LABEL=CentOS-7-livecd-x86_64 ro rd.live.image quiet rhgb rd.live.check initrdefi /isolinux/initrd0.img } submenu 'Troubleshooting -->' { menuentry 'Start CentOS Linux 7 Live in basic graphics mode' --class fedora --class gnu-linux --class gnu --class os { linuxefi /isolinux/vmlinuz0 root=live:LABEL=CentOS-7-livecd-x86_64 ro rd.live.image quiet rhgb nomodeset initrdefi /isolinux/initrd0.img } } [root@santiagod ~]#
4. 系统镜像文件：sqashfs.img
[root@santiagod ~]# mount /mnt/LiveOS/squashfs.img livecd/ [root@santiagod ~]# tree livecd/ livecd/ └── LiveOS └── ext3fs.img 1 directory, 1 file [root@santiagod ~]# mount livecd/LiveOS/ext3fs.img /mnt/ [root@santiagod ~]# ls /mnt bin boot dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var