Dell Media Direct button

Dell Media Direct button

[Per Öberg]

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Hi

Some laptops, e.g., from Dell have a special button that they use to
boot a special embedded OS for media only instead of the ordinary OS.

For my Dell XPS1330M I can determine if the Media button was pressed by
first writing 0xf9 to port 0x70 and then testing bit 0x08 of port 0x71.

It would be really nice if such a test could be enabled in grub so that
grub can go directly to a specific menu alternative without showing the
gui if the media button was pressed.

Is this interesting? I'd like to contribute but I don't know where to start.

Regards Per Öberg

-- 
Per Öberg, Ph.D. Student
Address: Division of Vehicular Systems
Department of Electrical Engineering
Linköpings universitet
581 83 Linköping, SWEDEN
Phone: +46 (0)13-28 23 69
e-mail: oberg@isy.liu.se
PGP: http://www.fs.isy.liu.se/~oberg/0x61984A9D.asc


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Re: Dell Media Direct button

[Robert Millan]

On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
> Hi
> 
> Some laptops, e.g., from Dell have a special button that they use to
> boot a special embedded OS for media only instead of the ordinary OS.
> 
> For my Dell XPS1330M I can determine if the Media button was pressed by
> first writing 0xf9 to port 0x70 and then testing bit 0x08 of port 0x71.
> 
> It would be really nice if such a test could be enabled in grub so that
> grub can go directly to a specific menu alternative without showing the
> gui if the media button was pressed.
> 
> Is this interesting? I'd like to contribute but I don't know where to start.

Sounds interesting, but this needs some thought on how to design it.

I suppose what you want is change the 'default' variable.  Perhaps increase
it by 1?  But then, where do you do this?  grub_machine_init is too early as
'default' hasn't been set yet.

Maybe we could have a global 'int default_offset' variable that is initialized
in grub_machine_init and later on used by normal.mod?

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."

Re: Dell Media Direct button

[Vesa Jääskeläinen]

Robert Millan wrote:
> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
>> Hi
>>
>> Some laptops, e.g., from Dell have a special button that they use to
>> boot a special embedded OS for media only instead of the ordinary OS.
>>
>> For my Dell XPS1330M I can determine if the Media button was pressed by
>> first writing 0xf9 to port 0x70 and then testing bit 0x08 of port 0x71.
>>
>> It would be really nice if such a test could be enabled in grub so that
>> grub can go directly to a specific menu alternative without showing the
>> gui if the media button was pressed.
>>
>> Is this interesting? I'd like to contribute but I don't know where to start.
> 
> Sounds interesting, but this needs some thought on how to design it.
> 
> I suppose what you want is change the 'default' variable.  Perhaps increase
> it by 1?  But then, where do you do this?  grub_machine_init is too early as
> 'default' hasn't been set yet.
> 
> Maybe we could have a global 'int default_offset' variable that is initialized
> in grub_machine_init and later on used by normal.mod?

Nah... Do a module to query for it and if it is there then use scripting
to do alternative path within script. Much better and more convenient.
And you can use script to increment default variable if needed :)

Re: Dell Media Direct button

[Colin D Bennett]

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On Wed, 20 Aug 2008 12:12:59 +0200
Robert Millan <rmh@aybabtu.com> wrote:

> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
> > Hi
> > 
> > Some laptops, e.g., from Dell have a special button that they use to
> > boot a special embedded OS for media only instead of the ordinary
> > OS.
> > 
> > For my Dell XPS1330M I can determine if the Media button was
> > pressed by first writing 0xf9 to port 0x70 and then testing bit
> > 0x08 of port 0x71.
> > 
> > It would be really nice if such a test could be enabled in grub so
> > that grub can go directly to a specific menu alternative without
> > showing the gui if the media button was pressed.
> > 
> > Is this interesting? I'd like to contribute but I don't know where
> > to start.
> 
> Sounds interesting, but this needs some thought on how to design it.
> 
> I suppose what you want is change the 'default' variable.  Perhaps
> increase it by 1?  But then, where do you do this?  grub_machine_init
> is too early as 'default' hasn't been set yet.
> 
> Maybe we could have a global 'int default_offset' variable that is
> initialized in grub_machine_init and later on used by normal.mod?

If I pressed the "Media Direct" button, I would also want to have a
timeout of 0, since by pressing the Media Direct button instead of the
power button, I've already indicated which entry I want to boot, and
there is no need to show the menu -- unless, perhaps, we decided to
show a different "media" menu... so hopefully giving all the power to
the grub.cfg script would be enough to make all this possible.

Regards,
Colin

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Re: Dell Media Direct button

[Javier Martín]

2008/8/20 Colin D Bennett <colin@gibibit.com>:
> On Wed, 20 Aug 2008 12:12:59 +0200
> Robert Millan <rmh@aybabtu.com> wrote:
>
>> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
>> > Hi
>> >
>> > Some laptops, e.g., from Dell have a special button that they use to
>> > boot a special embedded OS for media only instead of the ordinary
>> > OS.
>> >
>> > For my Dell XPS1330M I can determine if the Media button was
>> > pressed by first writing 0xf9 to port 0x70 and then testing bit
>> > 0x08 of port 0x71.
>> >
>> > It would be really nice if such a test could be enabled in grub so
>> > that grub can go directly to a specific menu alternative without
>> > showing the gui if the media button was pressed.
>> >
>> > Is this interesting? I'd like to contribute but I don't know where
>> > to start.
>>
>> Sounds interesting, but this needs some thought on how to design it.
>>
>> I suppose what you want is change the 'default' variable.  Perhaps
>> increase it by 1?  But then, where do you do this?  grub_machine_init
>> is too early as 'default' hasn't been set yet.
>>
>> Maybe we could have a global 'int default_offset' variable that is
>> initialized in grub_machine_init and later on used by normal.mod?
>
> If I pressed the "Media Direct" button, I would also want to have a
> timeout of 0, since by pressing the Media Direct button instead of the
> power button, I've already indicated which entry I want to boot, and
> there is no need to show the menu -- unless, perhaps, we decided to
> show a different "media" menu... so hopefully giving all the power to
> the grub.cfg script would be enough to make all this possible.
>
> Regards,
> Colin
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>
>

Well, I own a XPS1330 myself (I'm writing from it now, as I'm taking a
week at the beach in Benidorm ^^). This functionality could be
implemented by a module that used the pre-menu hooks proposed by Bean:
it would check the status before the menu is shown, then act on the
result.

However, all this assumes that pressing that key creates no additional
side effect like the replacement of the MBR by the system firmware,
booting another MBR written in flash memory or something like that: I
thought the choice took place at the "real" MBR, but disassembling it
revealed that it does not use the mentioned I/O ports interface, so
most likely what the system firmware does is set the active flag in
the MediaDirect partition.

I'm ready to check any related patches on the actual hardware _once
I'm back in Madrid_ because here I have no recovery tools.

-Habbit

Re: Dell Media Direct button

[Per Öberg]

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Javier Martín wrote:
> 2008/8/20 Colin D Bennett <colin@gibibit.com>:
>> On Wed, 20 Aug 2008 12:12:59 +0200
>> Robert Millan <rmh@aybabtu.com> wrote:
>>
>>> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
>>>> Hi
>>>>
>>>> Some laptops, e.g., from Dell have a special button that they use to
>>>> boot a special embedded OS for media only instead of the ordinary
>>>> OS.
>>>>
>>>> For my Dell XPS1330M I can determine if the Media button was
>>>> pressed by first writing 0xf9 to port 0x70 and then testing bit
>>>> 0x08 of port 0x71.
>>>>
>>>> It would be really nice if such a test could be enabled in grub so
>>>> that grub can go directly to a specific menu alternative without
>>>> showing the gui if the media button was pressed.
>>>>
>>>> Is this interesting? I'd like to contribute but I don't know where
>>>> to start.
>>> Sounds interesting, but this needs some thought on how to design it.
>>>
>>> I suppose what you want is change the 'default' variable.  Perhaps
>>> increase it by 1?  But then, where do you do this?  grub_machine_init
>>> is too early as 'default' hasn't been set yet.
>>>
>>> Maybe we could have a global 'int default_offset' variable that is
>>> initialized in grub_machine_init and later on used by normal.mod?
>> If I pressed the "Media Direct" button, I would also want to have a
>> timeout of 0, since by pressing the Media Direct button instead of the
>> power button, I've already indicated which entry I want to boot, and
>> there is no need to show the menu -- unless, perhaps, we decided to
>> show a different "media" menu... so hopefully giving all the power to
>> the grub.cfg script would be enough to make all this possible.
>>
>> Regards,
>> Colin
>>
>> _______________________________________________
>> Grub-devel mailing list
>> Grub-devel@gnu.org
>> http://lists.gnu.org/mailman/listinfo/grub-devel
>>
>>
> 
> Well, I own a XPS1330 myself (I'm writing from it now, as I'm taking a
> week at the beach in Benidorm ^^). This functionality could be
> implemented by a module that used the pre-menu hooks proposed by Bean:
> it would check the status before the menu is shown, then act on the
> result.
> 
> However, all this assumes that pressing that key creates no additional
> side effect like the replacement of the MBR by the system firmware,
> booting another MBR written in flash memory or something like that: I
> thought the choice took place at the "real" MBR, but disassembling it
> revealed that it does not use the mentioned I/O ports interface, so
> most likely what the system firmware does is set the active flag in
> the MediaDirect partition.
> 
> I'm ready to check any related patches on the actual hardware _once
> I'm back in Madrid_ because here I have no recovery tools.
> 
> -Habbit
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel

It works for me =)

See how below...

There might be different firmware versions out there and there's been a
lot of fuss about early versions of MD screwing up you partition table.
There has also been suggestions on how to disable it by overwriting your
MBR (http://ubuntuforums.org/showthread.php?t=606345).

There seems to be a number of different versions in the range of 1-3 and
some uses a hidden HPA partion while some "hides" the partition by
changing the partition id. The installation process and the possibility
to upgrade between the different version indicates (not same as proof, i
know) that the firmware does about the same for the different releases
and that it is the MBR that is important since this is what you install
to make it work.

Dan Goodell has a website that describes his findings of how the Dell
MBR works (http://www.goodells.net/dellrestore/hpa-issues.htm). On this
website he indicates that these ports exists. I believe that his
documentation is for MD v1-2 and I have v3.3. He has disassembled the
MBR code and the procedure showed in the part he sent me showed out to
work perfectly when using in my test setup.

--------------------------------------------------------------------------
My setup:
--------------------------------------------------------------------------
Comp: Dell XPS1330M,
Media Direct version: 3.3
Delivered: 2008-07-14
Disk layout:
 - grub legacy on MBR,
 - 100Mb (/dev/sda1, Main grub partiton, config chainloads sda2, sda3 or
sda5)
 - 100Mb  (/dev/sda2, geexbox, with own grub and grub config files in /boot)
 -  30Gb, (/dev/sda3, Kubuntu with own grub and grub config files)
 - Extended partition ~250Gb linux (/dev/sda5, Not using yet but with
test-boot-loader) ,~2Gb swap (/dev/sda6) N

I have a small boot loader written from scratch, which is attached to
the mail, that i dd to /dev/sda5 using "dd if=boot.bin of=/dev/sda5
count=512 bs=1"

If i press the MD button it will show a splash screen and then show grub
main menu, same menu as with ordinary power button (but the graphics
mode is different). I can then choose to chainload /dev/sda5 which
changes the graphics mode and turns the screen red for MD or green for
ordinary power button (or was it the opposite...)

Sometimes when i press the MD button it will hang for a while before
showing me the grub menu, pressing esc will then go directly to grub. I
have not done any statistics of when this happens.

Also, sometimes the first part of bootup will take forever but I am
unsure of why. This might indicate that the firmware is looking for
something on disk (or just that i have triggered some complete POST by
aborting the boot process in some way, the BIOS indicates that this is
possible)

If someone wants to test my boot code please be warned. The MD button
has been known to screw things up and I can't guarantee that that my dd
command is correct. Also, I might have changed something since I tried
it yesterday and I haven't got my computer with me so I cant't test the
version I'm sending. I am, however, very curios if this works for anyone
else so I can't wait till I tested it again...

Regards Per Öberg


[-- Attachment #2: boot.bin --]
[-- Type: application/octet-stream, Size: 512 bytes --]

[-- Attachment #3: boot_loader.asm --]
[-- Type: text/plain, Size: 2468 bytes --]

[org 0x0]       ; Offset zero is desired

jmp START       ; jump to executable code 

; definition of boot sector data for a diskette
        
BS_OEMName      db "MSWIN4.1"    ; 8 characters 
BPB_BytsPerSec  dw 0x0200        ; 512 bytes per sector
BPB_SecPerClus  db 0x01          ; one sector per cluster
BPB_RsvdSecCnt  dw 0x0001        ; one reserved sector
BPB_NumFATs     db 0x02          ; two FATs
BPB_RootEntCnt  dw 0x00E0        ; 224 entries 
BPB_TotSec16    dw 0x0B40        ; 2880 sectors on disk
BPB_Media       db 0xF0          ; media type code
BPB_FATSz16     dw 0x0009        ; 9 sectors in one FAT
BPB_SecPerTrk   dw 0x0012        ; 18 sectors per track
BPB_NumHeads    dw 0x0002        ; 2 heads
BPB_HiddSec     dd 0x00000000    ; no hidden sectors
BPB_TotSec32    dd 0x00000000    ; no FAT32 sectors
BS_DrvNum       db 0x00          ; drive number 0
BS_Reserved1    db 0x00          ; reserved
BS_BootSig      db 0x29          ; extended boot signature
BS_VolID        dd 0x12345678    ; serial number 
BS_VolLab       db "a_nice_disc" ; volume label 
BS_FilSysType   db "FAT12   "    ; file system 


%define MD_Get_MD_Status 0xf9	
%define MD_Write_Port	 0x70
%define MD_Read_Port	 0x71
%define MD_Bit_To_Test   0x08

	
START:				; start of CODE
	cli                     ; disable interrupts 

;; Enable 320x200 graphics mode
	mov 	eax,0x13	
	int 	0x10

;; Check if the button is pressed
	mov 	al,MD_Get_MD_Status
	out 	MD_Write_Port,al
	in 	al,MD_Read_Port
	test 	al,MD_Bit_To_Test
	mov	al,0x0
	out 	MD_Write_Port,al 
	jz 	set_red
	

;; Set green in first palette position
set_green:	
	mov	ax,0
        mov	dx,0x3c8	; Set first palette value
        out	dx,al
        inc	dx		; Palette is at 0x3c9
        mov	al,0x00		; Set red value
        out	dx,al		
        mov	al,0xff		; Set green value
        out	dx,al		
        mov	ax,0x0		; Set blue value
        out	dx,al		
	jmp	hang_here	


;; Set red in first palette position	
set_red:	
	mov	ax,0
        mov	dx,0x3c8	; Set first palette value
        out	dx,al
        inc	dx		; Palette is at 0x3c9
        mov	al,0xff		
        out	dx,al		; Set red value
        mov	al,0x0
        out	dx,al		; Set green value
        mov	ax,0x0
        out	dx,al		; Set blue value
	
	
hang_here:
	jmp hang_here
;; ----------------------
;; Finish up
;; ----------------------
	
times 512-($-$$)-2 db 0 ; make the code exactly 512 bytes
dw 0xAA55               ; the required final two bytes for a boot sector

[-- Attachment #4: Makefile --]
[-- Type: text/plain, Size: 535 bytes --]

# Per Öberg

BINDIR=.
# Build tools
CC=gcc
LD=gcc
NASM=nasm
NFLAGS=-f elf
NFLAGS_BIN = -f bin 
EXTRA_CFLAGS=
#EXTRA_CFLAGS=-g -DDEBUG 
CFLAGS= -m32 -Wall  -std=c89 -pedantic -Wunreachable-code
LFLAGS= -m32 

OBJS = boot_loader.o
TARGETS = 

all:
	nasm  -f bin -o boot.bin boot_loader.asm

#dd:
#	dd if=boot.bin of=/dev/sda5 bs=1 count=512

cleanup:
	find . -name '*.[aos]' -o -name '*~' -type f | xargs rm -f
	find . -name 'semantic.cache' | xargs rm -f

clean: cleanup
	cd $(BINDIR) ; rm -f $(TARGETS)


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email;internet:oberg@isy.liu.se
title:Doktorand (PhD Student)
tel;work:+46 (0)13 - 282369
tel;fax:+46 (0)13 - 282035
tel;home:+46 (0)13 - 212825
tel;cell:+46 (0)70 - 4857936
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url:http://www.fs.isy.liu.se/~oberg/
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Re: Dell Media Direct button

[Stefan Reinauer]

Robert Millan wrote:
> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
>   
>> Hi
>>
>> Some laptops, e.g., from Dell have a special button that they use to
>> boot a special embedded OS for media only instead of the ordinary OS.
>>
>> For my Dell XPS1330M I can determine if the Media button was pressed by
>> first writing 0xf9 to port 0x70 and then testing bit 0x08 of port 0x71.
>>
>> It would be really nice if such a test could be enabled in grub so that
>> grub can go directly to a specific menu alternative without showing the
>> gui if the media button was pressed.
>>
>> Is this interesting? I'd like to contribute but I don't know where to start.
>>     
>
> Sounds interesting, but this needs some thought on how to design it.
>
> I suppose what you want is change the 'default' variable.  Perhaps increase
> it by 1?  But then, where do you do this?  grub_machine_init is too early as
> 'default' hasn't been set yet.
>
> Maybe we could have a global 'int default_offset' variable that is initialized
> in grub_machine_init and later on used by normal.mod?
>
>   

The sequence of writing to port 0x70 / reading from port 0x71 reflects
reading from the computer's "cmos" nvram memory.
bit 7 of 0x70 is reserved for disabling NMIs, so the actual information
is stored in byte 0x79[8] in the cmos.

To allow full flexibility, there should just be a module that allows
reading / writing the cmos values (could also be useful for other
things, such as reading a boot order set by the bios).

Everything else makes more sense in scripting:
- changing "default"
- changing "timeout"
- support for bit operations in the parser
- etc...

-- 
coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br.
      Tel.: +49 761 7668825 • Fax: +49 761 7664613
Email: info@coresystems.de  • http://www.coresystems.de/
Registergericht: Amtsgericht Freiburg • HRB 7656
Geschäftsführer: Stefan Reinauer • Ust-IdNr.: DE245674866

Re: Dell Media Direct button

[Javier Martín]

2008/8/21 Stefan Reinauer <stepan@coresystems.de>:
> Robert Millan wrote:
>> On Wed, Aug 20, 2008 at 10:57:22AM +0200, Per Öberg wrote:
>>
>>> Hi
>>>
>>> Some laptops, e.g., from Dell have a special button that they use to
>>> boot a special embedded OS for media only instead of the ordinary OS.
>>>
>>> For my Dell XPS1330M I can determine if the Media button was pressed by
>>> first writing 0xf9 to port 0x70 and then testing bit 0x08 of port 0x71.
>>>
>>> It would be really nice if such a test could be enabled in grub so that
>>> grub can go directly to a specific menu alternative without showing the
>>> gui if the media button was pressed.
>>>
>>> Is this interesting? I'd like to contribute but I don't know where to start.
>>>
>>
>> Sounds interesting, but this needs some thought on how to design it.
>>
>> I suppose what you want is change the 'default' variable.  Perhaps increase
>> it by 1?  But then, where do you do this?  grub_machine_init is too early as
>> 'default' hasn't been set yet.
>>
>> Maybe we could have a global 'int default_offset' variable that is initialized
>> in grub_machine_init and later on used by normal.mod?
>>
>>
>
> The sequence of writing to port 0x70 / reading from port 0x71 reflects
> reading from the computer's "cmos" nvram memory.
> bit 7 of 0x70 is reserved for disabling NMIs, so the actual information
> is stored in byte 0x79[8] in the cmos.
>
> To allow full flexibility, there should just be a module that allows
> reading / writing the cmos values (could also be useful for other
> things, such as reading a boot order set by the bios).
>
> Everything else makes more sense in scripting:
> - changing "default"
> - changing "timeout"
> - support for bit operations in the parser
> - etc...
>
> --
> coresystems GmbH • Brahmsstr. 16 • D-79104 Freiburg i. Br.
>      Tel.: +49 761 7668825 • Fax: +49 761 7664613
> Email: info@coresystems.de  • http://www.coresystems.de/
> Registergericht: Amtsgericht Freiburg • HRB 7656
> Geschäftsführer: Stefan Reinauer • Ust-IdNr.: DE245674866
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>

So what about a new "nvram" module in i386-pc that creates a variable
$NVRAM hooked to routines getting/setting the live contents of the
cmos memory? Then menu scripts can check its contents, among them the
MediaDirect button.

-Habbit

Re: Dell Media Direct button

[Robert Millan]

On Thu, Aug 21, 2008 at 02:13:05PM +0200, Stefan Reinauer wrote:
> 
> The sequence of writing to port 0x70 / reading from port 0x71 reflects
> reading from the computer's "cmos" nvram memory.
> bit 7 of 0x70 is reserved for disabling NMIs, so the actual information
> is stored in byte 0x79[8] in the cmos.
> 
> To allow full flexibility, there should just be a module that allows
> reading / writing the cmos values (could also be useful for other
> things, such as reading a boot order set by the bios).

Ah, good catch.  For the record, we already have code that accesses cmos,
in the date handling functions recently added by Bean.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."