Syslinux (简体中文)
Syslinux是一个优秀的启动加载器集合,可以从硬盘、光盘或通过 PXE 的网络引导启动系统。支持的 文件系统 包括 FAT, ext2, ext3, ext4和非压缩的单设备 Btrfs.
BIOS 系统
启动流程
- 电脑启动时,BIOS 会先加载磁盘开始的 440 字节 MBR 启动代码(
/usr/lib/syslinux/bios/mbr.bin
或/usr/lib/syslinux/bios/gptmbr.bin
) - MBR 寻找活动分区(设置了 boot 标记的 MBR 分区),假设是
/boot
分区。 - 找到这个分区后, MBR 启动代码会执行卷启动记录程序(VBR=volume boot record)。对于 Syslinux 来说,VBR 就是
/boot/syslinux/ldlinux.sys
开始扇区的代码, 由extlinux --install
命令创建。 - VBR 会加载剩余的
ldlinux.sys
。ldlinux.sys
开始扇区是被写死进卷启动记录程序里的。对于 btrfs 来说,因为文件不断移动导致ldlinux.sys
扇区的位置不断变化,而让上面方法失效。从而使得整个syslinux需要被存储在文件系统之外。程序将被存储在卷启动记录程序之后。 -
ldlinux.sys
会接着加载/boot/syslinux/ldlinux.c32
核心模块,这个模块包含因为文件大小限制,无法放入ldlinux.sys
的代码。 - 当 syslinux 完全加载完毕,它将自动查找配置文件,配置文件名是
/boot/syslinux/syslinux.cfg
或/boot/syslinux/extlinux.conf
- 找到之后,将加载整个配置文件,否则,将进入命令行窗口,显示
boot:
提示。
在 BIOS 上安装
安装 软件包 syslinux。如果启动分区是 FAT,需要同时安装 mtools.
- 安装 gptfdisk 之后才能支持 GPT,参考#Automatic install[broken link: invalid section]部分。
- 如果你的启动分区是 FAT,还需要安装 mtools.
相关的软件包安装完成之后,还需要将启动加载器代码写入磁盘的对应扇区位置。有自动脚本和手动安装两种方式。
自动完成安装
syslinux-install_update
是Arch特有的, Syslinux上游不提供/支持。Please direct any bug reports specific to the script to the Arch Bug Tracker and not upstream.
syslinux-install_update脚本将自动安装启动代码(一般是VBR), 复制COM32模块到/boot/syslinux
, 设置启动标识,安装到MBR.可自动根据softraid处理MBR和 GPT磁盘。
2. 确认/boot
是否已经加载
3. 运行脚本syslinux-install_update
,参数使用 -i (安装) -a (设可启动标识) -m (安装到mbr)
/usr/sbin/syslinux-install_update -i -a -m
4. 修改配置文件 /boot/syslinux/syslinux.cfg
手工完成安装
/dev/
)路径之前添加挂载点。您计划安装Syslinux的启动分区必须包含FAT,ext2,ext3,ext4或Btrfs文件系统。您不必把它安装在文件系统的根目录上,比如把磁盘 /dev/sda1
挂在到 /boot
。 举个例子, 可以在syslinux
子目录里安装 Syslinux:
# mkdir /boot/syslinux
如果您希望使用除基本引导提示之外的任何菜单或配置,请把/usr/lib/syslinux/bios/
里的所有.c32
文件复制到 /boot/syslinux/
. Do not symlink them.
# cp /usr/lib/syslinux/bios/*.c32 /boot/syslinux/
安装bootloader. 对 挂载后的,格式是FAT, ext2/3/4, 或者 btrfs 的启动分区使用 extlinux:
# extlinux --install /boot/syslinux
或者, 对于一个卸载的,格式是FAT的启动分区使用syslinux:
# syslinux --directory syslinux --install /dev/sda1
在此之后,继续安装适用于分区表的Syslinux引导代码::
-
mbr.bin
will be installed for an #MBR partition table[broken link: invalid section], or -
gptmbr.bin
will be installed for a #GUID partition table[broken link: invalid section]
as described in the next sections. See Master Boot Record for further general information.
blkid -s PTTYPE -o value /dev/sda
.MBR分区表
需要标识启动分区为激活状态.可用这些工具实现:fdisk, cfdisk, sfdisk, (g)parted.最后结果看起来是这样:
# fdisk -l /dev/sda [...] Device Boot Start End Blocks Id System /dev/sda1 * 2048 104447 51200 83 Linux /dev/sda2 104448 625142447 312519000 83 Linux
安装到主启动卷区:
# dd bs=440 count=1 conv=notrunc if=/usr/lib/syslinux/bios/mbr.bin of=/dev/sda
GUID Partition Table aka GPT
Main article GUID Partition Table
Bit 2 of the attributes for the /boot
partition need to be set.
# sgdisk /dev/sda --attributes=1:set:2
This would toggle the attribute legacy BIOS bootable on partition 1
Verify:
# sgdisk /dev/sda --attributes=1:show 1:2:1 (legacy BIOS bootable)
安装主启动卷区:
# dd bs=440 conv=notrunc count=1 if=/usr/lib/syslinux/bios/gptmbr.bin of=/dev/sda
重启
- 如果此时重启,会有提示,以确认是自动启动还是给出一个启动菜单,此时需要创建一个配置文件。
- 如果你在另外一个跟文件夹(比如:在安装磁盘)通过chroot来安装SYSLINUX:
# syslinux-install_update -i -a -m -c /mnt
UEFI 系统
UEFI Syslinux 的局限性
- UEFI Syslinux application
syslinux.efi
cannot be signed bysbsign
(from sbsigntool) for UEFI Secure Boot. Bug report - https://bugzilla.syslinux.org/show_bug.cgi?id=8
- Using TAB to edit kernel parameters in UEFI Syslinux menu lead to garbaged display (text on top of one-another). Bug report - https://bugzilla.syslinux.org/show_bug.cgi?id=9
- UEFI Syslinux does not support chainloading other EFI applications like
UEFI Shell
orWindows Boot Manager
. Bug report - https://bugzilla.syslinux.org/show_bug.cgi?id=17
- UEFI Syslinux may not boot in some Virtual Machines like QEMU/OVMF or VirtualBox or some VMware products/versions and in some UEFI emulation environments like DUET. A Syslinux contributor has confirmed no such issues present on VMware Workstation 10.0.2 and Syslinux-6.02. Bug reports - https://bugzilla.syslinux.org/show_bug.cgi?id=21 and https://bugzilla.syslinux.org/show_bug.cgi?id=23
- Memdisk is not available for UEFI. Bug report - https://bugzilla.syslinux.org/show_bug.cgi?id=30
安装
- 安装来自official repositories的 syslinux 和 efibootmgr。然后按如下步骤安装 syslinux 到 EFI System Partition (ESP) :
- 复制 syslinux 文件到 ESP (将
$esp
替换为ESP的挂载点, 通常是/boot
):
# mkdir -p $esp/EFI/syslinux # cp -r /usr/lib/syslinux/efi64/* $esp/EFI/syslinux
- Setup boot entry for Syslinux using efibootmgr:
# efibootmgr -c -d /dev/sdX -p Y -l /EFI/syslinux/syslinux.efi -L "Syslinux"
/dev/sdXY
是包含引导程序的分区
- 按照#配置创建或编辑
$esp/EFI/syslinux/syslinux.cfg
#Configuration[broken link: invalid section].
配置
syslinux的配置文件 syslinux.cfg
必须和syslinux放在同一个目录下,在我们的例子中,是 '/boot/syslinux/'
启动器将自动寻找这两个配置文件:syslinux.cfg
(优先) 或者 extlinux.conf
补充:
- Instead of LINUX, the keyword KERNEL can also be used. KERNEL tries to detect the type of the file, while LINUX always expects a Linux kernel.
- TIMEOUT 的值是1/10秒,也就是50代表5秒
示例
比较简单的 Syslinux 配置
这是一个非常简单的配置,有启动提示,并且在5秒后自动启动第一个系统。
配置文件:
PROMPT 1 TIMEOUT 50 DEFAULT arch LABEL arch LINUX ../vmlinuz-linux APPEND root=/dev/sda2 ro INITRD ../initramfs-linux.img LABEL archfallback LINUX ../vmlinuz-linux APPEND root=/dev/sda2 ro INITRD ../initramfs-linux-fallback.img
若不想看到提示,设置PROMPT(显示时间)为0.
文本的启动菜单
把模块menu COM32复制到syslinux目录中,即可使用文本菜单:
# cp /usr/lib/syslinux/menu.c32 /boot/syslinux/
若没有给/boot单独分区,且和/usr同一分区,那么,也可以仅使用一个软链接:
# ln -s /usr/lib/syslinux/menu.c32 /boot/syslinux/
配置:
UI menu.c32 PROMPT 0 MENU TITLE Boot Menu TIMEOUT 50 DEFAULT arch LABEL arch MENU LABEL Arch Linux LINUX ../vmlinuz-linux APPEND root=/dev/sda2 ro INITRD ../initramfs-linux.img LABEL archfallback MENU LABEL Arch Linux Fallback LINUX /vmlinuz-linux APPEND root=/dev/sda2 ro INITRD /initramfs-linux-fallback.img
更多信息可见: http://git.kernel.org/?p=boot/syslinux/syslinux.git;a=blob;f=doc/menu.txt.
图形化的启动菜单
把vesamenu COM32移入到syslinux目录中,可使用图形启动界面:
# cp /usr/lib/syslinux/vesamenu.c32 /boot/syslinux/
若没有给/boot单独分区,且和/usr同一分区,那么,也可以仅使用一个软链接: :
# ln -s /usr/lib/syslinux/vesamenu.c32 /boot/syslinux/
This config uses the same menu design as the Arch Install CD: syslinux.cfg
The background file can be found here: splash.png
Config:
UI vesamenu.c32 DEFAULT arch PROMPT 0 MENU TITLE Boot Menu MENU BACKGROUND splash.png TIMEOUT 50 MENU WIDTH 78 MENU MARGIN 4 MENU ROWS 5 MENU VSHIFT 10 MENU TIMEOUTROW 13 MENU TABMSGROW 11 MENU CMDLINEROW 11 MENU HELPMSGROW 16 MENU HELPMSGENDROW 29 # Refer to http://syslinux.zytor.com/wiki/index.php/Doc/menu MENU COLOR border 30;44 #40ffffff #a0000000 std MENU COLOR title 1;36;44 #9033ccff #a0000000 std MENU COLOR sel 7;37;40 #e0ffffff #20ffffff all MENU COLOR unsel 37;44 #50ffffff #a0000000 std MENU COLOR help 37;40 #c0ffffff #a0000000 std MENU COLOR timeout_msg 37;40 #80ffffff #00000000 std MENU COLOR timeout 1;37;40 #c0ffffff #00000000 std MENU COLOR msg07 37;40 #90ffffff #a0000000 std MENU COLOR tabmsg 31;40 #30ffffff #00000000 std LABEL arch MENU LABEL Arch Linux LINUX ../vmlinuz-linux APPEND root=/dev/sda2 ro INITRD ../initramfs-linux.img LABEL archfallback MENU LABEL Arch Linux Fallback LINUX ../vmlinuz-linux APPEND root=/dev/sda2 ro INITRD ../initramfs-linux-fallback.img
Since Syslinux 3.84 vesamenu.c32 supports the "MENU RESOLUTION $WIDTH $HEIGHT" directive.
To use it, insert "MENU RESOLUTION 1440 900" into your config for a 1440x900 resolution.
The background picture has to have exactly the right resolution however as syslinux will otherwise refuse to load the menu.
Chainloading
If you want to chainload other operating systems (such as Windows) or boot loaders, copy (or symlink) the chain.c32 module to the syslinux folder (for details, see the instructions in the previous section). Then, create a section in the configuration file:
LABEL windows MENU LABEL Windows COM32 chain.c32 APPEND hd0 3
hd0 3 is the third partition on the first BIOS drive - drives are counted from zero, but partitions are counted from one. For more details about chainloading, see [3].
If you have grub2 installed in your boot partition, you can chainload it by using:
LABEL grub2 MENU LABEL Grub2 COM32 chain.c32 append file=../grub/boot.img
This maybe required for booting from iso images.
使用内存测试 memtest
使用下面的 LABEL章节部分,可加载(需要安装软件包:memtest86+,否则不起作用):
LABEL memtest MENU LABEL Memtest86+ LINUX ../memtest86+/memtest.bin
使用硬件探测工具HDT
HDT (Hardware Detection Tool) displays hardware information. Like before, the .c32 file has to be copied or symlinked from /boot/syslinux/.
For pci info either copy or symlink /usr/share/hwdata/pci.ids
to /boot/syslinux/pci.ids
LABEL hdt MENU LABEL Hardware Info COM32 hdt.c32
重启和关闭电源
Use the following sections to reboot or power off your machine.
LABEL reboot MENU LABEL Reboot COM32 reboot.c32 LABEL poweroff MENU LABEL Power Off COMBOOT poweroff.com
常见问题
I have a Syslinux Prompt - Yikes!
You can type in the LABEL name of the entry that you want to boot (as per your syslinux.cfg). If you used the example configs just type
boot: arch
If you get an error that the config file could not be loaded you can pass your needed boot parameters, e.g.:
boot: ../vmlinuz-linux root=/dev/sda2 ro initrd=../initramfs-linux.img
If you don't have access to 'boot:' in ramfs, and therefore temporarily unable to boot kernel again
1) create temp directory, in order to mount your root partition (if it doesn't exist already)
mkdir -p /new_root
2) mount / under /new_root (in case /boot/ is on same partition, otherwise you'll need to mount them both)
mount /dev/sd[a-z][1-9] /new_root
3) use 'vi' and edit syslinux.cfg again to suit your needs and save file;
4) reboot
某些电脑中,会出现没找到默认配置或者界面
Certain motherboard manufacturers have less compatibility for booting from USB devices than others. While an ext4 formatted usb drive may boot on a more recent computer, some computers may hang if the boot partition containing the kernel and initrd are not on a fat16 partition. to prevent an older machine from loading ldlinux and failing to read syslinux.cfg, use cfdisk to create a fat-16 partition (<=2GB) and format with
# pacman -S dosfstools # mkfs.msdos -F 16 /dev/sda1
then install and configure syslinux.
MISSING OPERATING SYSTEM
If you get this message, check if the partition that contains /boot
has the boot flag enabled. If the flag is enabled, then perhaps this partition starts at sector 1 rather than sector 63 or 2048. Check this with fdisk -l. If it starts at sector 1, you can move the partition(s) with gparted from a rescue disk. Or, if you have a separate boot partition, you can back up /boot with
cp -a /boot /boot.bak
and then boot up with the arch install disk. Next, use cfdisk to delete the /boot partition, and recreate it. This time it should begin at the proper sector, 63. Now mount your partitions and chroot into your mounted system, as described in the beginners guide. Restore /boot with the command
cp -a /boot.bak/* /boot
Check if /etc/fstab is correct. Then run
/usr/sbin/syslinux-install_update -iam
and reboot.
Windows boots up! No Syslinux!
Solution: Make sure the partition that contains /boot has the boot flag enabled. Also, make sure the boot flag is not enabled on the windows partition. See the installation section above.
The MBR that comes with syslinux looks for the first active partition that has the boot flag set. The windows partition was likely found first and had the boot flag set. If you wanted you could use the MBR that windows or msdos fdisk provides.
进入子菜单,但干不了任何事
You select a menu entry and it does nothing. It "refreshes" the menu
This usually means that you have an error in your configuration. Hit TAB
to edit your boot parameters. Alternatively, press ESC
and type in the LABEL of your boot entry (Example: arch)
无法删除ldlinux.sys
ldlinux.sys has the immutable attribute set which prevents the file from being deleted or overwritten. This is because the sector location of the file must not change or else syslinux has to be reinstalled. To remove:
chattr -i /boot/syslinux/ldlinux.sys rm /boot/syslinux/ldlinux.sys
更多信息可见
- The Syslinux Project's website.