This guide describes how to connect serial console to server running Ubuntu 12.04.

Why is my guide special comparing to many others easily available on the WEB?

Well, there are plenty docs if you want to use to configure first standard serial port (COM1/ttyS0),

but I haven't found any guide how to add non-standard RS-232 port on the PCI-Express card.

Not the way, that it would allow you to work with GRUB remotely :-)

I have a small home server running Ubuntu 12.04.

It is running at the attic of my house and I didn't want to go there (especially at winter) each time the server is stuck at the boot stage or due to fsck problems.

The solution seemed to be obvious - RS-232 serial console connected to 1-port terminal server (serial/IP converter).

I have bought old used Lantronix MSS100 to get remote access to serial port:

But the problem was, that there was NO SERIAL PORT on the motherboard of my server.

It is X58 platform (1366 CPU socket) with Sapphire X58 PureBlack MB. It is awesome motherboard. Has a lot of features, over clocking tools, but NO SERIAL PORT.

So, I've bought a cheap no-name PCI-Express card with 2 RS-232 ports:

It has MosChip 9922 chipset.

Here are the things, that I have learned trying (and succeeding) to make things work - to get the Ubuntu console over serial RS-232 connector being able to see the kernel loading/booting process,

and even managing remotely the GRUB2 bootloader.

Let's start.

1. PCI-Express card installation.

The card have been inserted. PC started. Is the card visible to Ubuntu 12.04?

root@mysiaki4:~# dmesg |grep ttyS

[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.5.0-45-generic root=UUID=2cb2b9c0-fb80-4f39-9055-29f88c2288e4 ro console=tty0 console=ttyS4,115200n8

[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.5.0-45-generic root=UUID=2cb2b9c0-fb80-4f39-9055-29f88c2288e4 ro console=tty0 console=ttyS4,115200n8

[ 0.566237] 0000:04:00.0: ttyS4 at I/O 0xb880 (irq = 16) is a ST16650V2

[ 2.597316] console [ttyS4] enabled

[ 2.622031] 0000:04:00.1: ttyS5 at I/O 0xbc00 (irq = 17) is a ST16650V2

Yes! The ports were found as:

ttyS4 - I/O address 0xb880 IRQ16

ttyS5 - I/O address 0xbc00 IRQ17

This has been confirmed also by the 'setserial -g' (install the setserial if needed: apt-get install setserial):

root@mysiaki4:~# setserial -g /dev/ttyS*

/dev/ttyS0, UART: unknown, Port: 0x03f8, IRQ: 4

/dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3

/dev/ttyS2, UART: unknown, Port: 0x03e8, IRQ: 4

/dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3

/dev/ttyS4, UART: 16650V2, Port: 0xb880, IRQ: 16

/dev/ttyS5, UART: 16650V2, Port: 0xbc00, IRQ: 17

And checking the PCI cards instaled for the device id reported by dmesg (04 :00) :

root@mysiaki4:~# lspci |grep 04:00

04:00.0 Serial controller: MosChip Semiconductor Technology Ltd. PCIe 9922 Multi-I/O Controller

04:00.1 Serial controller: MosChip Semiconductor Technology Ltd. PCIe 9922 Multi-I/O Controller

root@mysiaki4:~#

As I wrote earlier there are no serial ports included on the motherboard (I have checked that couple times - no pin-headers, no connectors marked with COMx), but Ubuntu still reports the ttyS0 - ttyS3 (the standard COM1-COM4 RS-232 ports with well defined I/O addresses and interrupts) as present.

This is because in the PnP architecture these first 4 ports are usually assigned/defined by the BIOS at startup. So the Linux's kernel starts numbering the serial ports at PCI/PCI-Express cards counting from ttyS4 up.

2. Configure the Lantronix MSS100 - IP address, serial port speed, etc.

I'm not going to describe detailed steps there, as each terminal server will have different configuration steps.

3. Configure the port ttyS4 to work as serial console in Ubuntu 12.04.

I've created /etc/init/ttyS4.conf file:

# ttyS4 - getty

# This service maintains a getty on ttyS4 from the point the system is

# started until it is shut down again.

start on stopped rc or RUNLEFVEL=[12345]

stop on runlevel [!12345]

respawn

exec /sbin/getty -L 115200 ttyS4 vt102

Tell Ubuntu to start the terminal:

start ttyS4

Success - login prompt has appeared at the serial console.

4. Configure the kernel boot parameters, so the kernel startup messages will be printed to the ttyS4 console

Edit the /etc/default/grub. Add the following to the GRUB_CMDLINE_LINUX:

console=tty0 console=ttyS4,115200n8

tty0 says, that the booting messages will still be printed to the local terminal (monitor connected to the server)

ttyS4 says, that at the same time messages should go to the serial console

At this stage mine /etc/default/grub looked like this:

# If you change this file, run 'update-grub' afterwards to update

# /boot/grub/grub.cfg.

# For full documentation of the options in this file, see:

# info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0

GRUB_TIMEOUT=15

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

GRUB_CMDLINE_LINUX="console=tty0 console=ttyS4,115200n8"

Remember to regenerate /boot/grub/grub.cfg with the new config in /etc/default/grub by executing:

update-grub

Reboot the server and watch the new serial console:

sync;sync;reboot

5. Attempt to configure GRUB 1.99 to use serial port console.

Seeing the kernel boot process is great, but it would be even better to get GRUB menu / commands working over the serial console.

I've found, that to make GRUB2 (v1.99) working with serial console the following parameters need to be added to the /etc/default/grub:

GRUB_TERMINAL="console serial"

GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1"

GRUB_TERMINAL_INPUT="console serial"

GRUB_TERMINAL_OUTPUT="console serial"

unit - this is the serial port number

console - this is the monitor connected to the server

serial - this is the serial port we are going to use for remote GRUB access

The problem is, that the "unit" parameter accepts only values 0 - 3 - for the standard COM1-COM4 ports, with standard I/O addresses.

In theory support for non-standard ports is possible by using '--port" option instead of the "--unit" ad putting the I/O address of the card there.

I have tried this. I have entered to my /etc/default/grub the following:

GRUB_TERMINAL="console serial"

GRUB_SERIAL_COMMAND="serial --port=0xb880 --speed=115200 --word=8 --parity=no --stop=1"

GRUB_TERMINAL_INPUT="console serial"

GRUB_TERMINAL_OUTPUT="console serial"

Then update-grub, and sync;sync;reboot.

The result: server just hunged for good. The GRUB didn’t even show up on the local monitor.

I had to start the system from LiveCD and restore previous /boot/grub/grub.cfg file.

Some people mentioned, that nowadays PCI/PCI-Express cards have often different crystal frequency than the standard RS-232 ports used to be mounted on motherboards sometime ago.

This requires some special changes to the GRUB code to manage different divider values to get proper speeds.

One Guy even managed this for the PCI serial card that he owned and prepared base-clock frequency patch for GRUB . See the email thread and patch listing here:

http://lists.gnu.org/archive/html/grub-devel/2008-11/msg00017.html

Unfortunately it was not mentioned, for which version of GRUB release the patch is, and I couldn’t determine it by myself. Post was quite old (year 2008), so I thought, that maybe the problem has been already solved in newer version of GRUB.

6. Downloading the most recent GRUB version.

I decided to get the most recent GRUB2 developer version and try to apply the patch there.

The most recent version can be obtained via git. At the time I was doing this it was GRUB 2.02~beta2. Here is how I have done this:

apt-get install git

mkdir /install/grub

cd /install/grub

git clone git://git.savannah.gnu.org/grub.git

and when download finished:

cd grub

First I wanted just to compile the GRUB without any modifications, to see if it works.

I have read the INSTALL doc.

I have installed all required packages mentioned there: bison, gettext, binutils, flex, libdevmapper, sdl, libpciaccess, libusb, python, autoconf, automake, qemu, xorriso.

The exact package names were not mentioned in the GRUB INSTALL doc, so each time I have searched for appropriate name like this:

root@mysiaki4:/install/grub2/grub# apt-cache pkgnames |grep libdevmapper

libdevmapper1.02.1

libdevmapper-event1.02.1

libdevmapper-dev

and then installed the executable and headers like this:

apt-get install libdevmapper1.02.1

apt-get install libdevmapper-dev

When all packages have been found/installed I have started the compilation.

7. Prepare the “configure” script.

root@mysiaki4:/install/grub2/grub# ./autogen.sh

Importing unicode...

Importing libgcrypt...

Generating Automake input...

Saving timestamps...

Running autoreconf...

autoreconf: Entering directory `.'

autoreconf: configure.ac: not using Gettext

autoreconf: running: aclocal -I m4

autoreconf: configure.ac: tracing

autoreconf: configure.ac: AM_GNU_GETTEXT is used, but not AM_GNU_GETTEXT_VERSION

autoreconf: configure.ac: not using Libtool

autoreconf: running: /usr/bin/autoconf

autoreconf: running: /usr/bin/autoheader

autoreconf: running: automake --add-missing --copy --no-force

autoreconf: Leaving directory `.'

8. Executing the “configure”.

root@mysiaki4:/install/grub2/grub# ./configure

checking build system type... x86_64-unknown-linux-gnu

checking host system type... x86_64-unknown-linux-gnu

checking target system type... x86_64-unknown-linux-gnu

checking for a BSD-compatible install... /usr/bin/install -c

checking whether build environment is sane... yes

checking for a thread-safe mkdir -p... /bin/mkdir -p

checking for gawk... no

checking for mawk... mawk

checking whether make sets $(MAKE)... yes

checking for cmp... cmp

checking for bison... bison

checking for ranlib... ranlib

checking for gawk... (cached) mawk

checking for style of include used by make... GNU

checking for gcc... gcc

checking whether the C compiler works... yes

checking for C compiler default output file name... a.out

checking for suffix of executables...

checking whether we are cross compiling... no

checking for suffix of object files... o

checking whether we are using the GNU C compiler... yes

checking whether gcc accepts -g... yes

checking for gcc option to accept ISO C89... none needed

checking dependency style of gcc... gcc3

...

config.status: executing depfiles commands

config.status: executing po-directories commands

config.status: creating po/POTFILES

config.status: creating po/Makefile

*******************************************************

GRUB2 will be compiled with following components:

Platform: i386-pc

With devmapper support: Yes

With memory debugging: No

With disk cache statistics: No

With boot time statistics: No

efiemu runtime: Yes

grub-mkfont: Yes

grub-mount: No (need FUSE library)

starfield theme: Yes

With DejaVuSans font from /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf

With libzfs support: No (need zfs library)

Build-time grub-mkfont: Yes

Without unifont

Without liblzma (no support for XZ-compressed mips images) (need lzma library)

*******************************************************

9. Time for compilation.

root@mysiaki4:/install/grub2/grub# make

make all-recursive

make[1]: Entering directory `/install/grub2/grub'

Making all in grub-core/gnulib

make[2]: Entering directory `/install/grub2/grub/grub-core/gnulib'

make all-recursive

make[3]: Entering directory `/install/grub2/grub/grub-core/gnulib'

make[4]: Entering directory `/install/grub2/grub/grub-core/gnulib'

...

make[2]: Entering directory `/install/grub2/grub/po'

make[2]: Leaving directory `/install/grub2/grub/po'

Making all in docs

make[2]: Entering directory `/install/grub2/grub/docs'

restore=: && backupdir=".am$$" && \

am__cwd=`pwd` && CDPATH="${ZSH_VERSION+.}:" && cd . && \

rm -rf $backupdir && mkdir $backupdir && \

if (/bin/true --version) >/dev/null 2>&1; then \

for f in grub.info grub.info-[0-9] grub.info-[0-9][0-9] grub.i[0-9] grub.i[0-9][0-9]; do \

if test -f $f; then mv $f $backupdir; restore=mv; else :; fi; \

done; \

else :; fi && \

cd "$am__cwd"; \

if /bin/true -I . \

-o grub.info grub.texi; \

then \

rc=0; \

CDPATH="${ZSH_VERSION+.}:" && cd .; \

else \

rc=$?; \

CDPATH="${ZSH_VERSION+.}:" && cd . && \

$restore $backupdir/* `echo "./grub.info" | sed 's|[^/]*$||'`; \

fi; \

rm -rf $backupdir; exit $rc

restore=: && backupdir=".am$$" && \

am__cwd=`pwd` && CDPATH="${ZSH_VERSION+.}:" && cd . && \

rm -rf $backupdir && mkdir $backupdir && \

if (/bin/true --version) >/dev/null 2>&1; then \

for f in grub-dev.info grub-dev.info-[0-9] grub-dev.info-[0-9][0-9] grub-dev.i[0-9] grub-dev.i[0-9][0-9]; do \

if test -f $f; then mv $f $backupdir; restore=mv; else :; fi; \

done; \

else :; fi && \

cd "$am__cwd"; \

if /bin/true -I . \

-o grub-dev.info grub-dev.texi; \

then \

rc=0; \

CDPATH="${ZSH_VERSION+.}:" && cd .; \

else \

rc=$?; \

CDPATH="${ZSH_VERSION+.}:" && cd . && \

$restore $backupdir/* `echo "./grub-dev.info" | sed 's|[^/]*$||'`; \

fi; \

rm -rf $backupdir; exit $rc

make[2]: Leaving directory `/install/grub2/grub/docs'

Making all in util/bash-completion.d

make[2]: Entering directory `/install/grub2/grub/util/bash-completion.d'

../../config.status --file=grub:grub-completion.bash.in

config.status: creating grub

make[2]: Leaving directory `/install/grub2/grub/util/bash-completion.d'

make[1]: Leaving directory `/install/grub2/grub'

10. Installation of binary files

root@mysiaki4:/install/grub2/grub#make install

This step copies grub binary files (like grub-install, grub-mkconfig) to /usr/local/sbin and manual files to man directory.

It does not install new GRUB on the HDD.

11. Install the new compiled GRUB to hard drive boot sector

Still being in the /install/grub/grub directory execute the ./grub-install pointing the HDD you want the GRUB to be installed to:

root@mysiaki4:/install/grub/grub# ./grub-install /dev/sda

Installing for i386-pc platform.

Installation finished. No error reported.

12. Update the /boot/grub/grub.cfg based on our settings in the /etc/default/grub so it will match the new GRUB binary.

root@mysiaki4:/install/grub/grub# update-grub

Generating grub configuration file ...

Found linux image: /boot/vmlinuz-3.8.0-29-generic

Found initrd image: /boot/initrd.img-3.8.0-29-generic

Done

13. Restart the server to check if new GRUB is working

root@mysiaki4:/install/grub/grub# sync;sync;reboot

The result:

Ok, so the good thing is, that the GRUB version is 2.02~beta2.

But what happened to the menu? Where is my nice classic looking menu with listed kernel versions, recovery mode and memtest?

14. Check if the PCI-Express card with serial ports is visible to GRUB and could work as GRUB console.

So, when the new GRUB 2.02~beta2 appeared on the VGA screen connected to my server I have pressed the “c” key to get the command-line mode.

                          GNU GRUB version 2.02~beta2

   Minimal BASH-like line editing is supported. For the first word, TAB
   lists possible command completions. Anywhere else TAB lists possible
   device or file completions. ESC at any time exits.

First check – is my PCI-Express card visible to GRUB? I have used the lspci command and searched for the same device id that was mentioned in the dmesg and lspci output, when I was searching for ttyS ports under Ubuntu (point 1 of this doc):

grub> lspci
00:00.0 8086:3405 [0600] Host Bridge
00:01.0 8086:3408 [0604] PCI-PCI Bridge
00:02.0 8086:3409 [0604] PCI-PCI Bridge
...
04:00.0 9710:9922 [0700] Communication controller [PI 02]
04:00.1 9710:9922 [0700] Communication controller [PI 02]
...

ff:06.1 8086:2db1 [0600] Host Bridge
ff:06.2 8086:2db2 [0600] Host Bridge
ff:06.3 8086:2db3 [0600] Host Bridge
grub>

Ok, so the card and 2 serial ports are visible, but what is the I/O port address to use in the serial command?

I’ve found, that lcpci –i gives much more details:

grub> lspci -i
00:00.0 8086:3405 [0600] Host Bridge
00:01.0 8086:3408 [0604] PCI-PCI Bridge
        32-bit memory space 2 at 0x0000000000090900 [non-prefetchable]
        32-bit memory space 3 at 0x000000002000e0d0 [non-prefetchable]
        32-bit memory space 4 at 0x00000000fbe0fbe0 [non-prefetchable]
        IO space 5 at 0x1fff0
00:02.0 8086:3409 [0604] PCI-PCI Bridge
        32-bit memory space 2 at 0x0000000000080800 [non-prefetchable]
        32-bit memory space 3 at 0x00000000200000f0 [non-prefetchable]
        32-bit memory space 4 at 0x00000000fbd0fbd0 [non-prefetchable]
        IO space 5 at 0x1fff0
...

04:00.0 9710:9922 [0700] Communication controller [PI 02]
        IO space 0 at 0xb880
        32-bit memory space 1 at 0x00000000fbcfd000 [non-prefetchable]
        32-bit memory space 5 at 0x00000000fbcfc000 [non-prefetchable]
04:00.1 9710:9922 [0700] Communication controller [PI 02]
        IO space 0 at 0xbc00
        32-bit memory space 1 at 0x00000000fbcff000 [non-prefetchable]
        32-bit memory space 5 at 0x00000000fbcfe000 [non-prefetchable]
grub>

Ok, so the I/O port addresses are the same as reported by dmesg and setsetial commands.

Let’s check what the syntax of the serial command is:

grub> help serial
Usage: serial [OPTIONS...]
Configure serial port.

-u, --unit              Set the serial unit.
-p, --port              Set the serial port address.
-s, --speed             Set the serial port speed.
-w, --word              Set the serial port word length.
-r, --parity            Set the serial port parity.
-t, --stop              Set the serial port stop bits.
-b, --base-clock        Set the base frequency.
-f, --rtscts=on|off     Enable/disable RTS/CTS.
-h, --help              Display this help and exit.
    --usage             Display the usage of this command and exit.
grub>

Wow, so the “base-clock” patch, that I have mentioned at point 4 of this doc seemed to be included in the release 2.02~beta2.

Let’s try to configure first serial port at PCI-Express card:

grub> serial --port=0xb880 --speed=115200
grub>

Looks promising - no errors reported.

To redirect the output of GRUB to serial port we need to use the terminal_output command.

Similarly to be able input keys via remote serial connection, the termina_input command has to be used.

I’ve found, that terminal_output and terminal_input commands without any parameters give some valuable info:

grub> terminal_output
Active output terminals:
console
Available output terminals:
gfxterm serial_portb880 vga_text spkmodem mda_text cbmemc audio
grub>

grub> terminal_input
Active input terminals:
console
Available input terminals:
serial_portb880 at_keyboard
grub>

This is a great hint – so the active input/output is console, but I it mentioned, that something called serial_portb880 is also available.

So it looks, that the command serial --port=0xb880 has created new input / output channel: serial_portb880.

Ok, then let’s try to use it then:

grub> terminal_output console serial_portb880

Guess what. I got the prompt:

grub>

on my serial console output!!!

And after:

grub> terminal_input console serial_portb880

I could also use my remote keyboard J

Nice job. So the only remaining thing is to put the above serial card and input / output commands to the /etc/default/grub, rebuild the /boot/grub/grub.cfg with update-grub and everything should work perfect.

15. Get back the classic GRUB menu and add all the serial console parameters

I have found, that since the version 1.98 the GRUB uses different menu structure (with submenus), but for some reason I had simple menu (without the Advanced options shown above) when GRUB 1.99 was installed – just before installing the 2.02~beta2 version.

Some people wrote, that to restore the old - simple menu structure it is needed to add the following option to the /etc/default/grub:

GRUB_ENABLE_SUBMENU=false

Unfortunately this haven’t work in my case.

Moreover I have noticed, that for some reason the /etc/default/grub file is no longer checked by update-grub at all!

None of the parameters, that I have entered there had any result in the GRUB displayed on the monitor after reboot. Even when I’ve set GRUB_TIMEOUT=30 the GRUB displayed after reboot had default 5 seconds timeout.

This looks as a bug of the 2.02~beta2 version to me.

I had no more time to find the solution for this issue, so instead of reporting the problem to the GNU GRUB2 developers I have decided to write my own /boot/grub/grub.cfg file and to disable the update-grub and grub-mkconfig files, so my manually created grub.cfg will not get overwritten by some automatic patch installation or so.

So here is my final /boot/grub/grub.cfg file with one kernel version:

root@mysiaki4:/etc/default# cat /boot/grub/grub.cfg

# 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 ]; then

set have_grubenv=true

load_env

set default="0"

if [ "${prev_saved_entry}" ]; then

set saved_entry="${prev_saved_entry}"

save_env saved_entry

set prev_saved_entry=

save_env prev_saved_entry

set boot_once=true

function savedefault {

if [ -z "${boot_once}" ]; then

saved_entry="${chosen}"

save_env saved_entry

}

function recordfail {

set recordfail=1

if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi

}

function load_video {

insmod vbe

insmod vga

insmod video_bochs

insmod video_cirrus

}

serial --port=0xb880 --speed=115200

terminal_input console serial

terminal_output console serial

if [ "${recordfail}" = 1 ] ; then

set timeout=-1

else

set timeout=15

play 480 440 1

### END /etc/grub.d/00_header ###

### 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; then

clear

### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###

function gfxmode {

set gfxpayload="${1}"

if [ "${1}" = "keep" ]; then

set vt_handoff=vt.handoff=7

else

set vt_handoff=

}

if [ "${recordfail}" != 1 ]; then

if [ -e ${prefix}/gfxblacklist.txt ]; then

if hwmatch ${prefix}/gfxblacklist.txt 3; then

if [ ${match} = 0 ]; then

set linux_gfx_mode=keep

else

set linux_gfx_mode=text

else

set linux_gfx_mode=text

else

set linux_gfx_mode=keep

else

set linux_gfx_mode=text

export linux_gfx_mode

if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi

menuentry 'Ubuntu, with Linux 3.5.0-45-generic' --class ubuntu --class gnu-linux --class gnu --class os {

### recordfail

gfxmode $linux_gfx_mode

insmod gzio

insmod part_msdos msdos

insmod diskfilter mdraid1x

insmod ext2

set root='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d'

search --no-floppy --fs-uuid --set=root --hint='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d' 2cb2b9c0-fb80-4f39-9055-29f88c2288e4

echo 'Loading Linux 3.5.0-45-generic ...'

linux /boot/vmlinuz-3.5.0-45-generic root=UUID=2cb2b9c0-fb80-4f39-9055-29f88c2288e4 ro console=tty0 console=ttyS4,115200n8

echo 'Loading initial ramdisk ...'

initrd /boot/initrd.img-3.5.0-45-generic

}

menuentry 'Ubuntu, with Linux 3.5.0-45-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {

### recordfail

insmod gzio

insmod part_msdos msdos

insmod diskfilter mdraid1x

insmod ext2

set root='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d'

search --no-floppy --fs-uuid --set=root --hint='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d' 2cb2b9c0-fb80-4f39-9055-29f88c2288e4

echo 'Loading Linux 3.5.0-45-generic (recovery mode) ...'

linux /boot/vmlinuz-3.5.0-45-generic root=UUID=2cb2b9c0-fb80-4f39-9055-29f88c2288e4 ro recovery nomodeset console=tty0 console=ttyS4,115200n8

echo 'Loading initial ramdisk ...'

initrd /boot/initrd.img-3.5.0-45-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+) - only VGA monitor" {

insmod part_msdos msdos

insmod diskfilter mdraid1x

insmod ext2

set root='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d'

search --no-floppy --fs-uuid --set=root --hint='mduuid/f0d7cff3dbc9fc91fa853205ef834a0d' 2cb2b9c0-fb80-4f39-9055-29f88c2288e4

linux16 /boot/memtest86+.bin

}

### 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.

### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###

if [ -f $prefix/custom.cfg ]; then

source $prefix/custom.cfg;

### END /etc/grub.d/41_custom ###

root@mysiaki4:/etc/default#

16. The End

Here is movie showing the final result:

https://www.youtube.com/watch?v=p6mg4p3OSVc

If you have any comments or know how to make GRUB 2.02~beta2 use the /etc/default/grub configuration – please send me email to pklawit(at)gmail(dot)com.

Best Regards,

Piotr