Dell Venue 8 Pro imaging/eMMC

[Sebastian Roth]

Others seam to have issues with Samsung eMMC disks as well. See here:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1422338
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1471989

But notice the different models, MDGAGC in the first and MCGAFB in the second bug report. Not sure if those were ever solved.

From what I can see in the first screenshots your model is a MBG4GC which I sadly cannot find much about when searching for those error messages. Not sure if this is related: https://dev-nell.com/rpmb-emmc-errors-under-linux.html

I am sorry but I guess this won’t be an easy catch. You/we might need to get in contact with kernel developers. Not 100% sure yet.

Could you please try other live linux systems to see if one of them goes without the errors?

[AsGF2MX]

@Uncle-Frank Perhaps it’s not such a big issue after all:

• My understanding is the RPMB partition is effectively doing what regular desktops do with EEPROM chips - store OEM license keys
• AFAIK Windows does not treat this partition as mountable - it doesn’t show in disk manager (the tablet is out of battery at the moment - will post a pic in a bit)
• Theoretically if I could clone p1-p5 as listed above then I should be all set
• The license or OEM data in the rpmb can remain as is across each unit

So in theory, if we apply Nell’s patch to ignore the rpmb area, we should be able to make this work.

The question is what needs to be done to the initd to get it to work?

@Tom-Elliott

[Wayne Workman]

@AsGF2MX Would it be acceptable for FOG to provide a Windows PE environment via PXE Boot with an installation script for Windows 8.1 for this device to make it automated?

It’s not traditional I know… but what are you going to do? Go pay for a product when FOG can still help you?

I mean… If we created a PXE Option that booted windows PE and just went through a Windows Recovery process, would that be acceptable? It would apply applications and restore settings. I suppose with the FOG Client installed on this device, it’d rename it and join it to the domain later too.

Is this viable - at-least until we can get better support for your device?

[Tom Elliott]

@AsGF2MX from the fog init in debug, what is the output of uname -rm?

[AsGF2MX]

@Tom-Elliott It says 4.2.0 i686

[Sebastian Roth]

Tom pointed me to a discussion here in the forum about a similar issue some time ago. Search for emmc and you’ll find a thread with a user called d4rk3.

Could you please enter a FOG debug session and run the following two commands fdisk -l /dev/mmcblk0 and lsblk /dev/mmcblk0
I guess the output of fdisk will be empty. Would be interesting to see what you get from lsblk.

As far as I can see clonezilla is showing the partitions with fdisk because it is debian based and debian has added the mentioned patch. See here: https://launchpad.net/debian/+source/linux/3.16.7-ckt9-1 (“eMMC: Don’t initialize partitions on RPMB flagged areas”) I downloaded the debian patchset to look through it and it’s got this patch by Nell Hardcastle (https://dev-nell.com/rpmb-emmc-errors-under-linux.html) in it!

@Tom-Elliott Would you mind adding this patch to 4.2? I know you’ve done this for d4rk3 some months ago. Didn’t seam to work for him but I wonder why.

[Tom Elliott]

@Uncle-Frank I’m rebuilding now, should be done in about 5 minutes. I added the patch. Just a note, I don’t have a simple way to patch this to work around the block. I had to manually code the patch, which would only be good on a one-to-one patch of the version as things change quite often between kernel updates.

I, again, won’t know if this works until somebody tests/confirms it as well. Hopefully your suggestion here will be viable and help ALL users out with eMMC SSD Cards.

[Tom Elliott]

Patched mmc drivers and built kernels are now up and running. You can update by choosing the latest kernels in the kernel update list, or by simply rerunning installer if you’re running development versions.

Thank you,

[d4rk3]

I’ll give the kernel a whirl tomorrow at work and report back if anything’s changed.

[AsGF2MX]

@Uncle-Frank @Tom-Elliott the output of fdisk -l /dev/mmc* or lsblk with the same returns no such file or directory. This is even with the newest kernel.

Since we don’t even see the MMC device, I’ve been going through a few things over the weekend and I might have found something. The eMMC device is operating in ACPI mode per windows and also per Clonezilla. The HS200 device sits at ACPI\80860f41:0001 Comparing the dmesg outputs between clonezilla and fog, I don’t see the above address anywhere in the FOG dmesg output.

After a little poking around for Kernel issues with Baytrail, it turns out there is an extra kernel option needed to make Baytrail work in a sane manner: CONFIG_PINCTRL_BAYTRAIL=“y”

When I looked at the kernel options with your name in git, the above is not configured or even defined. Would you be able to set the above to “y” and recompile the 32-bit kernel once more please? If it is already there then something is a miss.

This seems to very specific to Baytrail which the Venue is using. I do not have any info on Cherrytrail. If this works then the patch sets applied earlier should also take out the rpmb issue so it should theoretically be the one kernel that just works!

References:
https://lists.debian.org/debian-kernel/2015/09/msg00023.html
https://bbs.archlinux.org/viewtopic.php?id=193180
https://embedded.communities.intel.com/thread/7507

[Sebastian Roth]

Looking through the links I find they are talking about SD cards not eMMC drives. Maybe I got this wrong?

I wish I had one of those devices here to poke around with it myself to make it work.

[AsGF2MX]

@Uncle-Frank Not all of them but the SD and eMMC controllers are on die so being unable to address them correctly could explain why it doesn’t show. I would think that at least mmc0 would show in FOG but it doesn’t - there is no dev node for the micro sd card - the SD card shown as SDA1 is actually a USB SD card reader.

http://cdn.arstechnica.net/wp-content/uploads/2013/09/Screen-Shot-2013-09-13-at-6.32.07-PM-640x423.jpg

Thoughts?

[Tom Elliott]

I’m adding CONFIG_PINCTRL_BAYTRAIL and other devices to the kernel as we speak, will be about 5-10 minutes.

[Tom Elliott]

Kernels are updated if you would be willing to give them a shot.

[AsGF2MX]

@Tom-Elliott I gave it a shot and no dice. Something is amiss and I keep comparing the Clonezilla boot process and that of FOG. The only thing I do notice is that the boot process of FOG is a whole lot quicker than that of FOG and also the /proc/iomem from clonezilla is a lot longer.

I am wondering if we need to patch the initxz with a /lib/modules/modules.builtin to make this work as I don’t see modules loading and am not sure how to detect if a module compiled in is actually getting used or not.

[Wayne Workman]

@AsGF2MX We need to get @Tom-Elliott a Dell Venue 8 pro he’s had a rough day.

http://www.newegg.com/Product/Product.aspx?Item=N82E16834298232&Tpk=N82E16834298232

[Sebastian Roth]

@AsGF2MX Could you please upload the full dmesg output of FOG and Clonezilla?

You should be able to safe the output on your NFS share. Bootup Clonezilla/FOG in debug mode and then:

mkdir /images
mount -t nfs -o nolock x.x.x.x:/images /images
dmesg > /images/dmesg_fog.txt
umount /images

Where x.x.x.x is the IP address of your FOG server… Don’t copy/paste the files here (way too long) but attach or upload them (http://pastebin.com/).

[AsGF2MX]

@Uncle-Frank Had to disappear for a bit as I got buried for a bit but hopefully I’m not empty handed and I’ve got something.

@Tom-Elliott I took the make file from the SVN and went through a few compiles - started fat - with a lot of suspected options ticked and eventually one set worked.

A little bit of reading on eMMC interfaces and after going through a few posts in various places, I then took a different approach - add a few items and compile then recompile and retry. When I enabled a few extra options more towards the I2C and SPI interfaces, I ended up with one set that worked and my makefile is attached. There is an SPI and I2C bus involved but it took some digging to find the connection and unfortunately I didn’t bookmark the page before my browser crashed out.

I did try to pull the image and although there were a few errors (I don’t have the patch sets applied) but I also do think part of it may have been because the partitions are in fact bitlockered - still trying to figure that part out.

MMCEnabledConfig.32

This post wouldn’t be complete without the pictures and a request:

I am betting if you recompile with the above make and the patches you applied, at least @d4rk3 should be up and running and myself, I am trying to figure out if I can sysprep the unit for the purpose of testing so that fog can read the partitions but I will need a little while for that.

[Wayne Workman]

@AsGF2MX BRAVO!

[Tom Elliott]

I will compare the differences between them and see what I can come up with. This may take a bit though, as you don’t know the differences between what I had and you added directly. Like specifically. So it will be a little bit of a wait, but I hope you can bare it.