Samsung responds to Galaxy S II / Note eMMC bug problem

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NOMIOMI

Senior Member
Nov 4, 2010
1,357
1,287
Abbottabad


If you own a Samsung Galaxy S II or the Galaxy Note and are a regular member of the xda-developers forum, you may already be aware of a bug with some of these devices where erasing the eMMC could hard brick your phone.

This problem would surface if the user tried to flash a custom ROM or kernel that used MMC_CAP_ERASE. Thankfully, developer Chainfire came up with an app that would let you know if your device was shipped with a faulty eMMC.

Apparently, this issue has existed for a long time now and even though it was noticed a couple of months ago and was much talked about in the developer community Samsung did not respond to it, until now.

According to user Daniel Hillenbrand on Google+, Samsung has said that "Patches will be out in form of new official ROMs and also sourcecode releases after testing, which might take some time."

If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected. If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out.

SOURCE
 
Last edited:

RandomPlayer

Senior Member
Nov 30, 2010
71
8
Stupid question but does that mean that we need to wait first Samsung to release something and then rom and kernel makers to implement it in their products? I just flashed slimics rom and now checked that I have brick bug, nice!

Sent from my GT-I9100
 
M

marcellocord

Guest
I don't really think it's Samsung fault. They have spend a lot of time working on those devices, and of course, bugs are all part of the development. I don't think that Samsung is a bad company, but they need at least to figure out the problem and fix in the next device or firmware, so that's enough to me.

edit: well, it's kindda samsung's fault, hehehe.
 
Last edited:

donalgodon

Senior Member
Jan 10, 2010
3,990
699
I have the bug, according to Chainfire's app, but I've never had any problems after many, many flashes.

Am I just lucky?

How likely are those whose eMMC chips are faulty in this way to be bitten by the bug?

I've typically flashed all new leaks of Stock ROMs only. How do we know if are using kernels based on sources where MMC_CAP_ERASE is present?
 
Last edited:

Azurren

Senior Member
Oct 5, 2010
102
29
I have the bug, according to Chainfire's app, but I've never had any problems after many, many flashes.

Am I just lucky?

How likely are those whose eMMC chips are faulty in this way to be bitten by the bug?

I've typically flashed all new leaks of Stock ROMs only.
It's only triggered if using certain kernels (Or, more worrying, some stock GNote builds)
There is a thread listing "bad" kernels and an explanation kicking around on XDA if you want to know more.
In short.. Stick to well known and well tested kernels and you'll never have a problem
 
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donalgodon

Senior Member
Jan 10, 2010
3,990
699
It's only triggered if using certain kernels (Or, more worrying, some stock GNote builds)
There is a thread listing "bad" kernels and an explanation kicking around on XDA if you want to know more.
In short.. Stick to well known and well tested kernels and you'll never have a problem

Does that list get updated?

How do we know if are using kernels based on sources where MMC_CAP_ERASE is present?

I assume that since this is such a potentially serious issue, the MMC_CAP_ERASE issue is something that devs are well aware of. I wasn't aware of it until very recently.

IF I understand correctly, are you saying that the stock kernels no longer have this issue or do they still and can MMC_CAP_ERASE be removed from the kernel?
 

mzone1510

Senior Member
Jan 2, 2011
357
19
Goa\Kuwait
Just curious, what effect does MMC_CAP_ERASE have? I mean what does it actually do? And is not being able to perform it somehow reduces the performance of our emmc chips?
 

AvRS

Senior Member
Dec 21, 2009
4,328
2,574
If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected. If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out.

I normally ignore posts like this but just need to clear something up as you only make things worse for new members who are unaware when you spread false information through a forum like this. Can you please remove or reword what you've said. I'll break it down for you:

If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected - This is fine as people can run that app.

If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out. - So wrong it hurts! Everyone should completely ignore this sentence and actually read the thread of the app which states all currently available kernels based on Update4 sources (so all custom kernels in the dev areas) are safe. It was particular leaks that raised this issue as found in an earlier Siyah beta which was rectified as quick as Gok could do it but to this day people still question devs on their kernels. Please read the thread and add useful guidance only or direct people to the post which states the safe kernels!

And as a last note, please don't post in kernel threads asking if they're safe, simply do a search as it's been asked stupid amounts of times and no more spam is required.

Thanks and happy flashing
 

superleeds27

Senior Member
Jun 21, 2010
5,449
717
Hull
I normally ignore posts like this but just need to clear something up as you only make things worse for new members who are unaware when you spread false information through a forum like this. Can you please remove or reword what you've said. I'll break it down for you:

If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected - This is fine as people can run that app.

If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out. - So wrong it hurts! Everyone should completely ignore this sentence and actually read the thread of the app which states all currently available kernels based on Update4 sources (so all custom kernels in the dev areas) are safe. It was particular leaks that raised this issue as found in an earlier Siyah beta which was rectified as quick as Gok could do it but to this day people still question devs on their kernels. Please read the thread and add useful guidance only or direct people to the post which states the safe kernels!

And as a last note, please don't post in kernel threads asking if they're safe, simply do a search as it's been asked stupid amounts of times and no more spam is required.

Thanks and happy flashing

Im sick of seeing people asking/commenting about this in the Kernel threads, when they have no idea what they are on about!
 

AvRS

Senior Member
Dec 21, 2009
4,328
2,574
Im sick of seeing people asking/commenting about this in the Kernel threads, when they have no idea what they are on about!

Indeed and unfortunately it starts due to threads like these, sorry OP.

Here's some further reading for those who avoid using search so sit down, read and then forget:
It would be beneficial to provide more information on the brick bug to avoid some people getting unnecessarily scared (such as most I9100 users).

This bug requires three things for you to be in danger, and ALL of these conditions must be met for danger:
1) A defective eMMC chip/fwrev that is unable to handle eMMC ERASE commands (command 38) properly. (I'll provide a link with more detail on the nature of the bug later) - This condition is the one Chainfire's new app checks for. By the way, M8G2FA fwrev 0x11 (seen on some Kindle Fires) is also suspected of being defective.
2) A recovery binary that attempts to erase partitions when formatting them. Most ICS recovery binaries fit in this category, most Gingerbread recoveries do not attempt to perform an erase operation so are safe. Note that also, an affected update-binary in a ZIP could be a cause of problems too. (e.g. flashing a firmware that has an ICS update-binary and formats the partition could cause a problem even with a "safe" recovery.) So a kernel can be repacked with a "safe" CWM (such as the most recent CF-Root releases) but it will still only be partially safe.
3) A kernel that allows attempts to erase a partition to actually happen. (as opposed to reporting "not supported" and doing nothing.) - A common way of rendering a kernel safe is to remove MMC_CAP_ERASE from the capability flags in drivers/mmc/mshci.c

As of June 6, 2012, this is what I know as far as kernels that meet condition 3:
  • All GT-I9100 ICS leaks and official releases are SAFE (MMC_CAP_ERASE not present)
  • All kernels based on GT-I9100 ICS Update4 sources are SAFE (MMC_CAP_ERASE not present) - This includes all CM9 nightlies for SGH-I777, GT-I9100, and GT-N7000, all GT-I9100 custom kernels I am aware of, and all SGH-I777 custom kernels I am aware of
  • All GT-N7000 ICS leaks are UNSAFE
  • All GT-N7000 ICS official kernels are UNSAFE
  • All kernels built from the GT-N7000 sources are UNSAFE unless the following condition is met:
  • MMC_CAP_ERASE is removed from the capability flags in drivers/mmc/host/mshci.c - check the kernel features for this. Franco.kernel R3 and later and all Speedmod ICS releases are SAFE due to this.
  • All SHW-M250S/K/L ICS kernels are suspected to be UNSAFE
  • All SHW-M250S/K/L ICS source releases as of this date are UNSAFE (SHW-M250L Update4 was the cause of the SiyahKernel 3.1rc6 incident. Other Siyah releases are SAFE)
  • All SPH-D710 ICS releases as of this date are UNSAFE - Rumor has it that the official OTA may have a fixed kernel, but it is recommended to consider this kernel UNSAFE until source code is released and can be reviewed.
  • The SGH-I777 UCLD3 leak is UNSAFE, as is most likely every other leak for that device. Fortunately nearly everyone is using I9100 Update4-based custom kernels.
  • SGH-I727 and SGH-T989 ICS leaks are UNSAFE - However as these two devices use separate recovery and operational kernels, if you have a Gingerbread recovery/kernel, you should be safe regardless of what you are booting for normal operation.

It's hard to get ALL of the cases and evaluate them, but in general in terms of levels of danger (As of June 6, 2012 - this could change with time):
SPH-D710 users are in the most danger - They have no official ICS releases AND the I9100 Update4 source base can't be used to build a usable kernel for their device without major developer work
GT-N7000 users are second on the list - They are the only ones outside of Korea to receive official ICS updates that trigger the eMMC firmware defect. However, I9100 Update4 sources required only minor work to create "safe" kernels, and developers know the proper procedure for rendering the official N7000 Update3 source drop "safe"
SGH-I777 users are next - I777 leaks proved to be dangerous a month or so ago. However, the SGH-I777 required the least amount of work to be able to use the GT-I9100 Update4 source base, and as a result, with the exception of the leaks themselves, nearly all I777 ICS kernels are based off of safe source code bases.
GT-I9100 users are in the least danger - No leak, official binary release, or source code release for this device has been dangerous. Only one I9100 kernel has ever proven dangerous and that was quickly pulled by its developer.

I am not evaluating the SHW-M250S/K/L in the above list, as while I know their source and binaries are dangerous, the language/culture barrier means we have very little information on how this fiasco is panning out for those users.

UPDATE:
We have at least one confirmed report of this bug occurring with KYL00M fwrev 0x12 on a Samsung Skyrocket (SGH-I727) with their ICS leak kernels
In addition, Samsung Hercules (SGH-T989) has the same fwrev and I've been told that they have observed bricks of this type with their ICS leaks

UPDATE 2:
I've received an email from a contact at Samsung who has indicated they are working on some sort of fix to be deployed to devices with an "UNSAFE" configuration listed above. I have requested that I receive an explicit list of which binary builds contain this fix, as without that I cannot know for sure which builds are fixed and which are not. Fixes are not yet deployed to affected devices.
 

kjgallardog

Member
Jul 13, 2009
13
3
Maracaibo
HELP!

I have bad news (for me, of course) my phone is bricked, I write here because I want my phone back and I find no solution so far for this model, only for the Note and Epic 4G. Anyone have any ideas to solve the problem of brick MMC_CAP_ERASE for i9100? I'm reading from 6am..
if the moderator feels that this post should not go here, is his right of disposal. I just want an answer and a possible solution. thanx
 

ghegpatatas

Member
Sep 29, 2012
44
5
I got the emmc bug too..good thing nothing happened when I flashed my phone. using siyah 4.1.5 kernel
 

vislavskid

Senior Member
Jan 12, 2012
286
64
ruski krstur
I got to emmc bug and o tried all stuff i have jtag-et device 4 times but nothing always same when instaling something my phone freazes. And i have byed new sgs2 and my old phone is just waiting bether times :eek:

Sent from my GT-I9100 using xda app-developers app
 

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  • 6
    Im sick of seeing people asking/commenting about this in the Kernel threads, when they have no idea what they are on about!

    Indeed and unfortunately it starts due to threads like these, sorry OP.

    Here's some further reading for those who avoid using search so sit down, read and then forget:
    It would be beneficial to provide more information on the brick bug to avoid some people getting unnecessarily scared (such as most I9100 users).

    This bug requires three things for you to be in danger, and ALL of these conditions must be met for danger:
    1) A defective eMMC chip/fwrev that is unable to handle eMMC ERASE commands (command 38) properly. (I'll provide a link with more detail on the nature of the bug later) - This condition is the one Chainfire's new app checks for. By the way, M8G2FA fwrev 0x11 (seen on some Kindle Fires) is also suspected of being defective.
    2) A recovery binary that attempts to erase partitions when formatting them. Most ICS recovery binaries fit in this category, most Gingerbread recoveries do not attempt to perform an erase operation so are safe. Note that also, an affected update-binary in a ZIP could be a cause of problems too. (e.g. flashing a firmware that has an ICS update-binary and formats the partition could cause a problem even with a "safe" recovery.) So a kernel can be repacked with a "safe" CWM (such as the most recent CF-Root releases) but it will still only be partially safe.
    3) A kernel that allows attempts to erase a partition to actually happen. (as opposed to reporting "not supported" and doing nothing.) - A common way of rendering a kernel safe is to remove MMC_CAP_ERASE from the capability flags in drivers/mmc/mshci.c

    As of June 6, 2012, this is what I know as far as kernels that meet condition 3:
    • All GT-I9100 ICS leaks and official releases are SAFE (MMC_CAP_ERASE not present)
    • All kernels based on GT-I9100 ICS Update4 sources are SAFE (MMC_CAP_ERASE not present) - This includes all CM9 nightlies for SGH-I777, GT-I9100, and GT-N7000, all GT-I9100 custom kernels I am aware of, and all SGH-I777 custom kernels I am aware of
    • All GT-N7000 ICS leaks are UNSAFE
    • All GT-N7000 ICS official kernels are UNSAFE
    • All kernels built from the GT-N7000 sources are UNSAFE unless the following condition is met:
    • MMC_CAP_ERASE is removed from the capability flags in drivers/mmc/host/mshci.c - check the kernel features for this. Franco.kernel R3 and later and all Speedmod ICS releases are SAFE due to this.
    • All SHW-M250S/K/L ICS kernels are suspected to be UNSAFE
    • All SHW-M250S/K/L ICS source releases as of this date are UNSAFE (SHW-M250L Update4 was the cause of the SiyahKernel 3.1rc6 incident. Other Siyah releases are SAFE)
    • All SPH-D710 ICS releases as of this date are UNSAFE - Rumor has it that the official OTA may have a fixed kernel, but it is recommended to consider this kernel UNSAFE until source code is released and can be reviewed.
    • The SGH-I777 UCLD3 leak is UNSAFE, as is most likely every other leak for that device. Fortunately nearly everyone is using I9100 Update4-based custom kernels.
    • SGH-I727 and SGH-T989 ICS leaks are UNSAFE - However as these two devices use separate recovery and operational kernels, if you have a Gingerbread recovery/kernel, you should be safe regardless of what you are booting for normal operation.

    It's hard to get ALL of the cases and evaluate them, but in general in terms of levels of danger (As of June 6, 2012 - this could change with time):
    SPH-D710 users are in the most danger - They have no official ICS releases AND the I9100 Update4 source base can't be used to build a usable kernel for their device without major developer work
    GT-N7000 users are second on the list - They are the only ones outside of Korea to receive official ICS updates that trigger the eMMC firmware defect. However, I9100 Update4 sources required only minor work to create "safe" kernels, and developers know the proper procedure for rendering the official N7000 Update3 source drop "safe"
    SGH-I777 users are next - I777 leaks proved to be dangerous a month or so ago. However, the SGH-I777 required the least amount of work to be able to use the GT-I9100 Update4 source base, and as a result, with the exception of the leaks themselves, nearly all I777 ICS kernels are based off of safe source code bases.
    GT-I9100 users are in the least danger - No leak, official binary release, or source code release for this device has been dangerous. Only one I9100 kernel has ever proven dangerous and that was quickly pulled by its developer.

    I am not evaluating the SHW-M250S/K/L in the above list, as while I know their source and binaries are dangerous, the language/culture barrier means we have very little information on how this fiasco is panning out for those users.

    UPDATE:
    We have at least one confirmed report of this bug occurring with KYL00M fwrev 0x12 on a Samsung Skyrocket (SGH-I727) with their ICS leak kernels
    In addition, Samsung Hercules (SGH-T989) has the same fwrev and I've been told that they have observed bricks of this type with their ICS leaks

    UPDATE 2:
    I've received an email from a contact at Samsung who has indicated they are working on some sort of fix to be deployed to devices with an "UNSAFE" configuration listed above. I have requested that I receive an explicit list of which binary builds contain this fix, as without that I cannot know for sure which builds are fixed and which are not. Fixes are not yet deployed to affected devices.
    4
    If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected. If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out.

    I normally ignore posts like this but just need to clear something up as you only make things worse for new members who are unaware when you spread false information through a forum like this. Can you please remove or reword what you've said. I'll break it down for you:

    If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected - This is fine as people can run that app.

    If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out. - So wrong it hurts! Everyone should completely ignore this sentence and actually read the thread of the app which states all currently available kernels based on Update4 sources (so all custom kernels in the dev areas) are safe. It was particular leaks that raised this issue as found in an earlier Siyah beta which was rectified as quick as Gok could do it but to this day people still question devs on their kernels. Please read the thread and add useful guidance only or direct people to the post which states the safe kernels!

    And as a last note, please don't post in kernel threads asking if they're safe, simply do a search as it's been asked stupid amounts of times and no more spam is required.

    Thanks and happy flashing
    3


    If you own a Samsung Galaxy S II or the Galaxy Note and are a regular member of the xda-developers forum, you may already be aware of a bug with some of these devices where erasing the eMMC could hard brick your phone.

    This problem would surface if the user tried to flash a custom ROM or kernel that used MMC_CAP_ERASE. Thankfully, developer Chainfire came up with an app that would let you know if your device was shipped with a faulty eMMC.

    Apparently, this issue has existed for a long time now and even though it was noticed a couple of months ago and was much talked about in the developer community Samsung did not respond to it, until now.

    According to user Daniel Hillenbrand on Google+, Samsung has said that "Patches will be out in form of new official ROMs and also sourcecode releases after testing, which might take some time."

    If you have a Galaxy S II or Galaxy Note, just use the Chainfire GotBrickbug app from here and see if the eMMC in your device is affected. If it is, refrain from any kind of ROM flashing (except for CM9 kernels, which are safe to flash) until the patch from Samsung starts rolling out.

    SOURCE
    1
    Atleast give source of info and links ?