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Diffstat (limited to 'chapter10/grub.xml')
| -rw-r--r-- | chapter10/grub.xml | 128 |
1 files changed, 100 insertions, 28 deletions
diff --git a/chapter10/grub.xml b/chapter10/grub.xml index 1b2335623..48db73bb0 100644 --- a/chapter10/grub.xml +++ b/chapter10/grub.xml @@ -18,12 +18,23 @@ <note> <para> - If your system has UEFI support and you wish to boot LFS with UEFI, - you should skip the instructions in this page but still learn the + This section assume your system has UEFI support and you wish to boot + LFS with UEFI and GRUB built following the instructions in Chapter 8. + </para> + <para> + If you've installed GRUB for UEFI with optional dependencies following + BLFS, you should skip the instructions in this page but still learn the syntax of <filename>grub.cfg</filename> and the method to specify a partition in the file from this page, and configure GRUB with UEFI - support using the instructions provided in - <ulink url="&blfs-book;postlfs/grub-setup.html">the BLFS page</ulink>. + using the instructions provided in + <ulink url="&blfs-book;postlfs/grub-setup.html">the BLFS page</ulink>, + but replace <parameter>--target=x86_64-efi</parameter> with + <parameter>--target=arm64-efi</parameter> for the ARM64 system. + </para> + <para> + If your system does not support UEFI or you don't want to use it, + you'll need to figure out how to configure the booting process of + the system on your own. </para> </note> @@ -36,18 +47,23 @@ just want to modify your current boot loader, e.g. Grub-Legacy, GRUB2, or LILO.</para></warning> - <para> Ensure that an emergency boot disk is ready to <quote>rescue</quote> + <para>Ensure that an emergency boot disk is ready to <quote>rescue</quote> the computer if the computer becomes unusable (un-bootable). If you do not - already have a boot device, you can create one. In order for the procedure - below to work, you need to jump ahead to BLFS and install - <userinput>xorriso</userinput> from the <ulink - url="&blfs-book;multimedia/libisoburn.html"> - libisoburn</ulink> package.</para> + already have a boot device, you can create one. To create a emergency + boot device for UEFI, consult section <quote>Create an Emergency Boot + Disk</quote> in + <ulink url="&blfs-book;postlfs/grub-setup.html">the BLFS page</ulink>.</para> -<screen role="nodump"><userinput>cd /tmp -grub-mkrescue --output=grub-img.iso -xorriso -as cdrecord -v dev=/dev/cdrw blank=as_needed grub-img.iso</userinput></screen> + </sect2> + + <sect2> + <title>Turn off Secure Boot</title> + <para>LFS does not have the essential packages to support Secure Boot. + To set up the boot process following the instructions in this section, + Secure Boot must be turned off from the configuration interface of the + firmware. Read the documentation provided by the manufacturer of your + system to find out how.</para> </sect2> <sect2> @@ -73,10 +89,31 @@ xorriso -as cdrecord -v dev=/dev/cdrw blank=as_needed grub-img.iso</userinput></ <sect2> <title>Setting Up the Configuration</title> - <para>GRUB works by writing data to the first physical track of the - hard disk. This area is not part of any file system. The programs - there access GRUB modules in the boot partition. The default location - is /boot/grub/.</para> + <para>GRUB works by creating an EFI executable in the EFI System + Partition (ESP). You can find the ESP with:</para> + +<screen role="nodump"><userinput>fdisk -l | grep 'EFI System'</userinput></screen> + + <para>If no ESP exists on your hard drive (for example, you are building + LFS on a fresh new system with a Live CD as the host distro), read + <ulink url="&blfs-book;postlfs/grub-setup.html">the BLFS page</ulink> + for the instruction to create an ESP on your hard drive.</para> + + <para>If the ESP is not mounted at + <filename class="directory">/boot/efi</filename> (in the chroot), + mount it now:</para> + +<screen role="nodump"><userinput>mkdir -pv /boot/efi +mount /boot/efi</userinput></screen> + + <note> + <para>The path to the device node is intentionally omitted in the + command. We expect the entry for mounting the ESP to + <filename class="directory">/boot/efi</filename> is already in + <filename>/etc/fstab</filename>. Add the entry before running the + command if you forgot to create an entry for the ESP in + <xref linkend="ch-bootable-fstab"/>.</para> + </note> <para>The location of the boot partition is a choice of the user that affects the configuration. One recommendation is to have a separate small @@ -101,23 +138,56 @@ xorriso -as cdrecord -v dev=/dev/cdrw blank=as_needed grub-img.iso</userinput></ class="partition">sda2</filename>.</para> <para>Install the GRUB files into <filename - class="directory">/boot/grub</filename> and set up the boot track:</para> + class="directory">/boot/grub</filename> and the GRUB EFI executable into + <filename class="directory">/boot/efi/EFI/BOOT/BOOTAA64.EFI</filename>:</para> <warning> - <para>The following command will overwrite the current boot loader. Do not - run the command if this is not desired, for example, if using a third party - boot manager to manage the Master Boot Record (MBR).</para> + <para>The following command will overwrite + <filename>BOOTAA64.EFI</filename>. Do not run the command if this is + not desired, for example, if it contains a third party boot manager. + You can backup it with <command>cp</command> as it's a regular + file.</para> </warning> -<screen role="nodump"><userinput>grub-install /dev/sda</userinput></screen> +<screen role="nodump"><userinput>grub-install --removable</userinput></screen> <note> - <para>If the system has been booted using UEFI, - <command>grub-install</command> will try to install files for the - <emphasis>x86_64-efi</emphasis> target, but those files - have not been installed in <xref linkend="chapter-building-system"/>. - If this is the case, add <option>--target i386-pc</option> to the - command above.</para> + <para> + <parameter>--removable</parameter> may seem strange here. The UEFI + firmware searches EFI executables for boot loaders in a hardcoded + path, <filename>EFI/BOOT/BOOTAA64.EFI</filename> in the ESP, and other + boot loader paths listed in the EFI variables. We've not installed + the utilities for manipulating EFI variables so we need to install + the EFI executable into the hardcoded path. The hardcoded path is + usually used by removable devices (for example, USB thumb devices) + so the <command>grub-install</command> option for this purpose is + named <parameter>--removable</parameter>. + </para> + <para> + UEFI implementation usually prefers the boot loaders with paths + recorded in an EFI variable, to the boot loader with the hardcoded + search path. You may need to invoke the boot device selection menu + or setting interface of your EFI firmware on next boot to explicitly + select the bootloader. + </para> + <para> + Some UEFI implementation may completely skip the hardcoded path if + there are other boot loaders in the same hard drive with paths + recorded in an EFI variable. Then you need to create an EFI + variable for the newly installed boot loader. Install + <ulink url="&blfs-book;postlfs/efibootmgr.html">efibootmgr</ulink>, + then run the following commands: + +<screen role="nodump"><userinput>mount -v -t efivarfs efivarfs /sys/firmware/efi/efivars +efibootmgr -B -L LFS || true +efibootmgr -c -L LFS -l '\EFI\BOOT\BOOTAA64.EFI' -d /dev/sda +umount /sys/firmware/efi/efivars</userinput></screen> + + Replace <filename>/dev/sda</filename> with the device node of the + hard drive where you are installing GRUB into. For some UEFI + firmwares, <option>-e 3</option> option may be needed for the + <command>efibootmgr -c</command> command. + </para> </note> <!-- This does not seem to be true any more @@ -147,6 +217,8 @@ insmod part_gpt insmod ext2 set root=(hd0,2) +insmod all_video + menuentry "GNU/Linux, Linux &linux-version;-lfs-&version;" { linux /boot/vmlinuz-&linux-version;-lfs-&version; root=/dev/sda2 ro }</literal> |