= Extlinux for CLFS Builds =

== Needed Files ==
Syslinux [[http://www.kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.02.tar.bz2]][[BR]]

Gnu-EFI [[http://sourceforge.net/projects/gnu-efi/files/gnu-efi_3.0u.orig.tar.gz]][[BR]]

Everything below is only needed if you're following the boot method of the build.

NASM [[http://www.nasm.us/pub/nasm/releasebuilds/2.07/nasm-2.07.tar.bz2]][[BR]]

== Changes for Cross-Tools Section ==

This build is only required if you're using the Boot Method of the build.

=== Build Nasm ===

./configure --prefix=/cross-tools &&[[BR]]
make &&[[BR]]
make install[[BR]]

== Changes for Boot Section ==

This build is only required if you're using the Boot Method of the build. 
You can also skip the building of Grub or Lilo.

=== Build GNU-EFI ===

==== IA32/64: ====
EFI_IA_NBITS=64    # 32 or 64 .

make PREFIX=cross-tools efi${EFI_IA_NBITS} &&[[BR]]
make PREFIX=cross-tools efi${EFI_IA_NBITS} install[[BR]]

=== Build Syslinux ===

make CROSS_COMPILE=${CLFS_TARGET}- installer &&[[BR]]
install -m 755 extlinux/extlinux /cross-tools/bin &&[[BR]]
install -d -m 755 /cross-tools/syslinux &&[[BR]]
install -m 644 mbr/mbr.bin /cross-tools/syslinux[[BR]]

=== Configure Extlinux ===

First we erase the current MBR on the disk, next we will install the MBR for Extlinux on
the Primary Boot Drive. I will assume the Primary Boot Drive is /dev/sda.[[BR]]


dd if=/dev/zero of=/dev/sda bs=446 count=1[[BR]]

==== Bootcode ====
BOOTCODE_TYP='gpt' ;    # 'gpt' (for GPT) or empty-string (for MBR).[[BR]]
dd bs=440 conv=notrunc count=1 if=/cross-tools/syslinux/${BOOTCODE_TYP}mbr.bin of=/dev/sda[[BR]]

Second we will install the Extlinux.sys file for bootup. This is the bootloader.[[BR]]
install -d ${CLFS}/boot[[BR]]
extlinux --install ${CLFS}/boot[[BR]]

Now we will create our extlinux.conf file. Change root_device to your root partition of your
Primary Boot Drive.[[BR]]

cat >> ${CLFS}/boot/extlinux.conf << "EOF"[[BR]]
default boot[[BR]]
prompt 0[[BR]]
timeout 10[[BR]]
[[BR]]
label boot[[BR]]
        kernel clfskernel-boot[[BR]]
        append rw root=root_device[[BR]]
EOF[[BR]]

== Changes for Final-System Section ==

=== Build Nasm ===

./configure --prefix=/usr &&[[BR]]
make &&[[BR]]
make install[[BR]]

=== Build GNU-EFI ===

==== IA32/64: ====
EFI_IA_NBITS=64    # 32 or 64 .

make PREFIX=usr efi${EFI_IA_NBITS} &&[[BR]]
make PREFIX=usr efi${EFI_IA_NBITS} install[[BR]]

=== Build Syslinux ===

Now we will build the final version of Syslinux, and we will copy the menu.c32 file
over so that we can have a menu at bootup.

make installer &&[[BR]]
make install &&[[BR]]
cp -ar /usr/share/syslinux/menu.c32 /boot[[BR]]

=== Configure Extlinux ===

First we erase the current MBR on the disk, next we will install the MBR for Extlinux on
the Primary Boot Drive. I will assume that the Primary Boot Drive is /dev/sda. We repeat this
step from above. Reinstalling this ensures that we are using the currently built
version of the file. When Syslinux is cross-compiled, some files are not made and
the pre-made ones are used instead. This reinstall will ensure that we now use the ones we just built.[[BR]]

dd if=/dev/zero of=/dev/sda bs=446 count=1[[BR]]

==== Bootcode ====
BOOTCODE_TYP='gpt' ;    # 'gpt' (for GPT) or empty-string (for MBR).[[BR]]
dd bs=440 conv=notrunc count=1 if=/usr/share/syslinux/${BOOTCODE_TYP}mbr.bin of=/dev/sda[[BR]]

Second we will install the extlinux.sys file for bootup. This is the bootloader.[[BR]]
extlinux --install /boot[[BR]]

Now we will create our extlinux.conf file. Change root_device to your root partition of your
Primary Boot Drive.[[BR]]

cat >> /boot/extlinux.conf << "EOF"[[BR]]
default menu.c32[[BR]]
prompt 0[[BR]]
menu title CLFS Boot Menu[[BR]]
[[BR]]
timeout 60[[BR]]
[[BR]]
label linux[[BR]]
        menu label CLFS Kernel {kernel_version}[[BR]]
        menu default[[BR]]
        kernel clfskernel-{kernel_version}[[BR]]
        append rw root=root_device[[BR]]
[[BR]]
label boot[[BR]]
        menu label CLFS Boot Stage Kernel[[BR]]
        kernel clfskernel-boot[[BR]]
        append rw root=root_device[[BR]]
EOF[[BR]]