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[R&D] Unlock Bootloaders

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alquimista

Senior Member
Mar 20, 2008
218
118
Los Angeles
{Q} aboot.c

That's from aboot_init, decompiled version available http://pastie.org/4339731

That looks like it comes from the aboot.c source here http://pastie.org/4340093
Note: CodeAurora does not endorse anything I am doing. However, I am following the copyright instructions to the letter.​

However, I don't see any of the strings from the target_fastboot_init section. ie:
Code:
	fastboot_register("continue", cmd_continue);
	fastboot_register("reboot", cmd_reboot);
	fastboot_register("reboot-bootloader", cmd_reboot_bootloader);
	fastboot_register("oem unlock", cmd_oem_unlock);
	fastboot_register("oem device-info", cmd_oem_devinfo);
	fastboot_publish("product", TARGET(BOARD));
	fastboot_publish("kernel", "lk");
	fastboot_publish("serialno", sn_buf);

Wouldn't "oem unlock" show up as a string if it were accessible?

Ta,
ALQI

EDIT: Also, what does this mean?
Code:
#define FASTBOOT_MODE   0x77665500
 
Last edited:

Ralekdev

Retired Senior Recognized Developer
Sep 4, 2010
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That looks like it comes from the aboot.c source here http://pastie.org/4340093
Note: CodeAurora does not endorse anything I am doing. However, I am following the copyright instructions to the letter.​

However, I don't see any of the strings from the target_fastboot_init section. ie:
Code:
	fastboot_register("continue", cmd_continue);
	fastboot_register("reboot", cmd_reboot);
	fastboot_register("reboot-bootloader", cmd_reboot_bootloader);
	fastboot_register("oem unlock", cmd_oem_unlock);
	fastboot_register("oem device-info", cmd_oem_devinfo);
	fastboot_publish("product", TARGET(BOARD));
	fastboot_publish("kernel", "lk");
	fastboot_publish("serialno", sn_buf);

Wouldn't "oem unlock" show up as a string if it were accessible?

Ta,
ALQI

EDIT: Also, what does this mean?
Code:
#define FASTBOOT_MODE   0x77665500

The aboot in the SGS3 is heavily based on lk, but also modified in certain areas. One of the places they changed was fastboot, where they replaced it with 2 other boot modes instead (odin and rdx). The normal fastboot stuff is mostly gone.

Setting the restart reason (at 0x2A03F65C) to FASTBOOT_MODE will make the phone boot into fastboot upon reboot even if the key combo isn't pressed. There are a few more possible values in the post from Adam earlier in the thread where he pasted the email I sent him.
 

open1your1eyes0

Senior Member
Dec 13, 2010
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enderblue

Member
May 14, 2010
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Setting the restart reason (at 0x2A03F65C) to FASTBOOT_MODE will make the phone boot into fastboot upon reboot even if the key combo isn't pressed. There are a few more possible values in the post from Adam earlier in the thread where he pasted the email I sent him.

The Params block (mmcblk0p10) doesn't address that high. I pulled that address from the mmcblk0 block and the existing data doesn't seem to suggest a current reboot reason.

What part of the memory is that address referencing?

Thanks,
EnderBlue
 
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Ralekdev

Retired Senior Recognized Developer
Sep 4, 2010
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The Params block (mmcblk0p10) doesn't address that high. I pulled that address from the mmcblk0 block and the existing data doesn't seem to suggest a current reboot reason.

What part of the memory is that address referencing?

Thanks,
EnderBlue

That's not an offset into the mmc, but rather part of the MSM_SHARED_IMEM_BASE region of memory. To write to it aboot does *(int*)0x2A03F65C = restart_reason, but depending on the current environment you may need to do more work to write there. Check arch_reset() in arch/arm/mach-msm/restart.c in the kernel Samsung released for how they do it.
 
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alquimista

Senior Member
Mar 20, 2008
218
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Los Angeles
{i} Qualcomm USB Settings

There is a hidden UI:
Code:
com.sec.android.app.phoneutil/com.sec.android.app.phoneutil.SetPortUartUsbMSM8960

I found it and many others using Logging Checker by TevE. If I long press on that item I get this:
phoneUtils_Uart1sm.png


When I press the big "Qualcomm USB Settings" button I get this:
phoneUtil_Uart2sm.png


From what I've read, and I could be very wrong, this is how to access Qualcomm diagnostics over usb. Unfortunately, I don't know much about what to do from there. I know RNDIS stands for Remote Network Driver Interface Specification. And RMNET is Qualcomm's proprietary version of RNDIS for their phones. I assume DM means Direct Media as in DMA direct media access, but I could be wrong.

I haven't had time to have a go at talking to the device using any of the last three ports or combos of ports. Could we possibly disable Qualcomm Secure boot with this? I've seen instructions on how to do it using Jtag, but I don't have a Jtag set up. The reason I bring it up, is because as I understand it Qualcomm Secure boot checks for any changes to the bootloader. If we could disable it, then cracking the bootloader might be a bit easier.

Ta,
ALQI

EDIT: I'm working on a text list of all the hidden UI's but I haven't had time to put it all together.
 
Last edited:

chadamir

Senior Member
Dec 15, 2010
143
31
Alquimista, QPST will probably not give you the ability to get around the bootloader. DM stands for diagnostic mode. You can read certain info off of the phone and write certain info to the phone with it, but it's a pain in the ass to get working. The builds floating around online are really old, and predate this phone by a long while.
 

alquimista

Senior Member
Mar 20, 2008
218
118
Los Angeles
Alquimista, QPST will probably not give you the ability to get around the bootloader. DM stands for diagnostic mode. You can read certain info off of the phone and write certain info to the phone with it, but it's a pain in the ass to get working. The builds floating around online are really old, and predate this phone by a long while.

Ta very much chadamir.

Well, I wrote a little script for launching IOTHiddenMenu, not that it'll be usefull but learning a bit of SL4A was fun:
Code:
import sys
import types
import android

droid = android.Android()
intent = droid.makeIntent(None,None,None,None,None,"com.android.hiddenmenu","com.android.hiddenmenu.IOTHiddenMenu",0x10100000)
droid.startActivityIntent(intent[1], False)

Its in python so you'd need to download SL4A and install the python interpreter to use it. It a fun little scripting layer though.

There's probably a much much simpler way to do it, but I like overcomplicated toys. ;)

Ta,
ALQI
 
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chadamir

Senior Member
Dec 15, 2010
143
31
You just need to make a shortcut to it using anycut or your launcher under activities. It would be useful if we could get it working under cm10 or aosp generally though. I have yet to figure out how to put the phone into the right usb mode.

Edit: It's clear that these modes can be entered into via cm10 if you look at init.qcom.usb.rc . I'm just not sure how to make a script that won't break something.

Edit 2: Here is the script I used to get it working in cm10 :)

echo 0 > /sys/class/android_usb/android0/enable 0
echo 04E8 > /sys/class/android_usb/android0/idVendor 04E8
echo 685D > /sys/class/android_usb/android0/idProduct 685D
echo smd,bam > /sys/class/android_usb/android0/f_rmnet/transports
echo diag > /sys/class/android_usb/android0/f_diag/clients
echo 1 > /sys/class/android_usb/android0/f_acm/instances
echo rmnet,acm,diag > /sys/class/android_usb/android0/functions
echo 1 > /sys/class/android_usb/android0/enable

use that in gscript lite http://forum.xda-developers.com/showthread.php?t=1785243 Based off of this thread.

Edit 3: Also, so it's clear you can use the mtp scripts in that thread to get back to normal.

Here are some things I found when comparing the nv data in cm10 vs stock. (I didn't go through everything)

Stock: NV item: 10 [NV_PREF_MODE_I],
NV_PREF_MODE_I 0: 00 24 00 00 00 00 00 00 00 00 00 00 00 00 00 00
In cm10 it was 00 04

Stock: NV item: 442 [NV_ROAM_PREF_I], index 0
NV_ROAM_PREF_I 0: 00 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00

In cm10 it was 00 01

I'm not sure if any of those values are static or if they change.

Here is a list of what many of these refer to: http://read.pudn.com/downloads125/sourcecode/windows/comm/529045/CDMA测试工具v2.6.3/Include/NV.h__.htm

I don't know whether or not any of these will help with the RIL or anything else.
 
Last edited:

natalic

Senior Member
Aug 5, 2008
276
37
There are various items that may change due to the RIL. Roaming pref sets Home, Auto, Home A, Home B. The other settings I believe is the settings related to the *#*#4636#*#*...not sure I'd need to check.

I know a lot about CDMA, so if you find something you got questions about, just ask.

They have nothing to do with the bootloader.

You just need to make a shortcut to it using anycut or your launcher under activities. It would be useful if we could get it working under cm10 or aosp generally though. I have yet to figure out how to put the phone into the right usb mode.

Edit: It's clear that these modes can be entered into via cm10 if you look at init.qcom.usb.rc . I'm just not sure how to make a script that won't break something.

Edit 2: Here is the script I used to get it working in cm10 :)

echo 0 > /sys/class/android_usb/android0/enable 0
echo 04E8 > /sys/class/android_usb/android0/idVendor 04E8
echo 685D > /sys/class/android_usb/android0/idProduct 685D
echo smd,bam > /sys/class/android_usb/android0/f_rmnet/transports
echo diag > /sys/class/android_usb/android0/f_diag/clients
echo 1 > /sys/class/android_usb/android0/f_acm/instances
echo rmnet,acm,diag > /sys/class/android_usb/android0/functions
echo 1 > /sys/class/android_usb/android0/enable

use that in gscript lite http://forum.xda-developers.com/showthread.php?t=1785243 Based off of this thread.

Edit 3: Also, so it's clear you can use the mtp scripts in that thread to get back to normal.

Here are some things I found when comparing the nv data in cm10 vs stock. (I didn't go through everything)

Stock: NV item: 10 [NV_PREF_MODE_I],
NV_PREF_MODE_I 0: 00 24 00 00 00 00 00 00 00 00 00 00 00 00 00 00
In cm10 it was 00 04

Stock: NV item: 442 [NV_ROAM_PREF_I], index 0
NV_ROAM_PREF_I 0: 00 ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00

In cm10 it was 00 01

I'm not sure if any of those values are static or if they change.

Here is a list of what many of these refer to: http://read.pudn.com/downloads125/sourcecode/windows/comm/529045/CDMA测试工具v2.6.3/Include/NV.h__.htm

I don't know whether or not any of these will help with the RIL or anything else.
 

E:V:A

Inactive Recognized Developer
Dec 6, 2011
1,449
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-∇ϕ
There is a hidden UI:
... I found it and many others using Logging Checker by TevE. If I long press on that item I get this:...

Great work! What you are seeing (above) is the software controlling the internal micro-USB multiplexer (MUX), which is used to switch between application processor (AP) and baseband processor (BP). It decides whether you are connected with one or the other. However, unlike older SGS1/2, on the SGS3, using the Qualcomm 8960, has integrated the modem functionality (BP) directly on the same "chip" as the AP. (AFIK. Remind you I don't own a SGS3.) Which is far more complicated (hardware wise) although more integrated than before. In addition the SGS3 have several chip based switches and MUXes, which help control UART, MHL, JTAG and Audio over USB connectivity, including classic JIG values.

Thus when you do your "long press" on Qualcomm USB settings, you are determining the protocols allowed over your USB settings, remembering that you can have several layers of communication protocols over one physical USB connection. (Just connect your device to Windows and see what appears in Device Manager...) So basically I think you're just choosing what device drivers should be used (on the PC side) when connecting the phone.

What would be interesting is to see what drivers are used during Odin operation and/or Qualcomm modem tuning/setup operations...

All though very off topic, ultimately we would like to see how to communicate directly with modem by AT command set, using a local shell...
 
Last edited:

xd.bx

Senior Member
May 14, 2011
431
292
Hi,

People might be wondering, could the same unlocking techniques that worked on HTC phones be applied here?

The main difference is that most exploits (unrevoked/alpharevx) relied on the fact that HBOOT itself is not signed until late 2011 and could be reflashed through a software vulnerability in it. In addition, the XTC Clip exploits the vendor's normal mecanism for unlocking, possibly because they extracted an RSA key from the official SIM.

A more likely avenue of research would be to discover a vulnerability in the boot rom (the PBL) thus allowing forever untethered boot, as it could not be patched. However the PBL is a rather simple piece of code as compared to the boot rom that is found on iPhones, thus reducing the likelyhood of finding a vuln (it is also very quite old - 2006 ? and very well conserved between MSM revisions).

I have more faith in finding a vuln in the Samsung bootloaders, they are less studied and implement a crapload of stuff, however keep in mind they can be patched at any point in time.

As for me I don't care much for locked phones anymore, and have stopped buying them since I discovered my WildFire was locked, then unlocked thanks to unrevoked, then relocked by HTC through an update, then fully unlocked by XTC Clip. What a pain.
 

alquimista

Senior Member
Mar 20, 2008
218
118
Los Angeles
Thoughts

Alquimista, QPST will probably not give you the ability to get around the bootloader. DM stands for diagnostic mode. You can read certain info off of the phone and write certain info to the phone with it, but it's a pain in the ass to get working. The builds floating around online are really old, and predate this phone by a long while.

I was thinking about QPST and the old WinCE hacking days. There may be some other tools that can be used, some specific to CDMA, I remember a samsung phone from way back in the day that I was modifying. I'll have to look into some old archives of mine, but it may produce something of use to us. I'll report back on that.

On another topic, is there anyway to disable QUALCOMM SECURE BOOT over USB? I've seen some older instructions for using JTAG on the MSM8660, but I don't have a JTAG set up, and I don't know the correct connections on the SGS3 board to DIY one together or even purchase a USB to JTAG adapter/kit.

Ta,
ALQI
 
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neyenlives

Senior Member
Oct 11, 2010
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I was thinking about QPST and the old WinCE hacking days. There may be some other tools that can be used, some specific to CDMA, I remember a samsung phone from way back in the day that I was modifying. I'll have to look into some old archives of mine, but it may produce something of use to us. I'll report back on that.

On another topic, is there anyway to disable QUALCOMM SECURE BOOT over USB? I've seen some older instructions for using JTAG on the MSM8660, but I don't have a JTAG set up, and I don't know the correct connections on the SGS3 board to DIY one together or even purchase a USB to JTAG adapter/kit.

Ta,
ALQI

I have heard, but do not know, that there may be plans to get one of the developer phones into Adam's hands to extract from. That may provide insight into how to disable Qualcomm Secure Boot no? Anyone care to shed some light on if this is still planned or not? Thanks
 
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AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
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Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
I have heard, but do not know, that there may be plans to get one of the developer phones into Adam's hands to extract from. That may provide insight into how to disable Qualcomm Secure Boot no? Anyone care to shed some light on if this is still planned or not? Thanks

I don't need another device. I want all of the partitions from a developer device and I'd like to work with someone who has one. Remote access via "WirelessADB" and the device set to be in the "DMZ" of a router would be sufficient for all tests I would need to do.

Just as an update, I'm slowly getting back to work. For those who were wondering, I packed up everything and moved. I have my stuff 90% set up. I'm just getting back on it. I'm working on compiling all of the Verizon GS3 exploits into a single CASUAL one-click package. Root, recovery, Busybox, Basic Hacking Tools.

Once I've got a CASUAL package put together I'll go through and read this thread again from start to finish and figure out what needs work... my mind is totally off-topic right now after a move. Time to get back to work. I hope to have some big news at the end of next week.
 

qv775219

Senior Member
Oct 8, 2010
248
538
Dallas
I wanted to assist with finding a place we could exploit. I am working on fully decompiling aboot.mbm. At an early glance looks like I found some interesting lines associated with the hexadecimal locations. I am going to break it down a little more to see what else I can find. :cowboy:




00035A03 88 51 55 41 4C 43 4F 4D 4D 20 53 45 43 55 52 45 êQUALCOMM SECURE
00035A13 42 4F 4F 54 3A 20 45 4E 41 42 4C 45 00 51 55 41 BOOT: ENABLE.QUA
00035A23 4C 43 4F 4D 4D 20 53 45 43 55 52 45 42 4F 4F 54 LCOMM SECUREBOOT
00035A33 3A 20 54 33 32 20 45 4E 41 42 4C 45 00 51 55 41 : T32 ENABLE.QUA
00035A43 4C 43 4F 4D 4D 20 53 45 43 55 52 45 42 4F 4F 54 LCOMM SECUREBOOT
00035A53 3A 20 44 49 53 41 42 4C 45 00 00 00 00 51 55 41 : DISABLE....QUA
00035A63 4C 43 4F 4D 4D 20 53 45 43 55 52 45 42 4F 4F 54 LCOMM SECUREBOOT
00035A73 3A 20 4E 4F 4E 2D 53 45 43 55 52 45 20 42 49 4E : NON-SECURE BIN
00035A83 41 52 59 00 00 51 55 41 4C 43 4F 4D 4D 20 53 45 ARY..QUALCOMM SE
00035A93 43 55 52 45 42 4F 4F 54 3A 20 4E 4F 4E 45 00 00 CUREBOOT: NONE..
 
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  • 561
    Verizon GS3 is now Bootloader UNLOCKED.
    We now have access to an unsecure bootloader. This was leaked by an African-Canadian Sock Monkey.

    Let me make this clear. If Samsung updates your device's bootloaders, using this tool could potentially brick your device. Once you apply this, never accept a factory update without first flashing the Odin Packages in the Original Post of this thread. As a general rule, you want to be the last guy to apply any Samsung update. Run custom.

    As of the date of this posting, this works great on Linux and it should work wonderfully on Mac too. NOTE: this may work on windows, but please, windows users.. learn to use your computer before you ask questions on XDA-Developers. This is one-click on Linux and Mac every darn time. If you're using Windows, I recommend downloading Windows Ubuntu Installer(WUBI) to install Ubuntu from within Windows.

    Download
    http://d-h.st/ypJ


    Instructions:
    1. Open this file
    2. Select Root with DebugFSRoot and Do It
    3. Select Flash Unsecure Aboot and Do It
    4. Use Odin or CWM to flash kernels to your device

    1zqwmlc.png

    To flash from device without the above tool:
    • root your device
    • Download this link to your /sdcard/Downloads/ folder: http://d-h.st/Piq
    • Type this in the terminal emulator
      Code:
      su -c dd if=/sdcard/Downloads/aboot.img of=/dev/block/mmcblk0p5

    This was tested with a Sprint kernel flashed via Odin. Although the Sprint kernel caused the device to have a blank screen due to hardware incompatibility, it's more than enough for a proof-of-concept. Stock bootloaders will not let you flash improper kernels with Odin and will cause the device not to boot. This corrects the problem. I'll leave implementation to other developers. If you feel uncomfortable flashing this on your own, wait for your favorite kernel developer to release something.

    Note to developers: This CASUAL package contains everything you need. A jar can be opened as a zip file. CASUAL format sticks all scripts in the /SCRIPTS/ folder. You can obtain all files needed from within this package, then repackage them into CWM format. In order to avoid a mass brick fest, please apply an assert to your CWM scripts to verify ro.build.version.incremental and do not allow updates past what has been tested. As of the time of this writing I535VRALG7B is safe.

    With the unlock of the GS3, this thread is locked. There will be no victory dancing in here. Move along to General or something. This thread will lie dormant until it is needed again in the future. Ralekdev will be releasing another exploit in the future as soon as this one stops working. Feel free to review what was learned until then.

    P.S. Sorry to those who I have offended by having posts removed. I'm also sorry to those who had their intelligence insulted before I had both of our posts removed. I hope you understand that in 6 months from now when everyone forgets about this thread but needs to catch back up, the information will still be right here in condensed format.
    173
    Rules:
    Do not post in here unless you have something constructive to say. "Thanks", "Hey this is wonderful", and any other comments like that are not wanted. They take up space and make it more difficult to find information. I'm requesting that this thread be heavily moderated. In order to work efficiently, information density must be kept high. We are all guilty of adding in a few off-topic sentances from time-to-time, but this thread is strictly business and I expect the moderators to moderate me as well.

    What is this?
    This is the place where we can research and develop a method to unlock the bootloader of the Verizon Galaxy SIII. Hopefully, this will be development at its finest.


    Why not just buy a developer edition
    GTFO! Not a single person got started developing by buying a developer phone. They started developing because they were unhappy with the features of their device and wanted something better. They wanted something more. This developer phone is a tax on developer innovation. We do not stand for that. We will break the security and we will enable XDA-Developers to do what they do best.

    Until security is broken and available for everyone, this device will get updates last, users will be unhappy because there are no additional features and Samsung violates the spirit of Open Source and copyright laws. Take a look at the bottom line of GPL-Violations.org FAQ located here: http://gpl-violations.org/faq/sourcecode-faq.html


    What are the goals?
    • Attain a bootloader recovery - 75% JTAG (the extra 25% will be for a user-friendly method)
      The Galaxy S3 is bootable from SDCard. In case of emergency this is needed. We need to verify that this works on the Verizon GS3 to bring up Odin. This will set up infrastructure for research.
    • Attain a full stock restoration via Odin or Heimdall - 90%
      For use with Odin3.
      Bootloader - BOOTLOADER_I535VRALF2_618049_REV09_user_low_ship.tar.md5 - 1.97 MB - Thanks nbsdx
      PDA - SCH-I535_VZW_1_20120705143513_fti2qg2lmf.zip
      NEED CSC PACKAGE (MODEM, PARAMS and Other Miscellaneous partitions). This is enough to recover a device though.
      To include bootloaders and recovery to a working and stock condition with the EMMC wiped entirely. Heimdall is a work in progress for this device. This will complete the infrastructure needed for research.
    • Collect information
      This will be the longest and most difficult part of this development. The information provided by Qualcomm is not readily available. Samsung is notoriously secretive about their bootloaders. Mainly we, as a community, will generate information. Please post any relevant datasheets, theory-of-operation, or manuals which you can find.
    • Provide a way to remove security checks from Odin3.] 100% - insecure aboot.img which may break in the future
      By removing security checks from Odin3 on the computer or the Loki daemon on the device we can flash anything through Odin or Heimdall.
    • Provide a way to bypass security checks within bootloaders. 200% we have two exploits, only one has been released.
      This is the ultimate goal. Once we can bypass the security checks, kernels can be flashed giving us the control required to develop


    Initial information
    [BOOTLOADER] Locked bootloader research and news: http://forum.xda-developers.com/showthread.php?t=1756919


    My own research

    SBL1 is the first booting partition. Qualcomm provides the Modem partition so it comes first on the EMMC. SBL1 is the first bootloader and that is specified by Qualcomm standards. Qualcom mmake sthe primitive bootloader and allows their customers (Samsung) to make a Secondary bootloader. Samsung chose to use three secondary bootloaders.

    The following 0p* are located in /dev/block/mmcblk*

    0p1 = modem
    Built by se.infra
    HUDSON_GA_D2_USA-VZW-HARDKEY-PROD-USER
    I take this to mean this Qualcomm modem was built in Hudson Georgia.
    I was not able to find signatures on this block :). This does NOT mean that there are no signatures on this block. The file is 33 megs. The file is unencrypted.
    The modem uses the BLAST Kernerl ver : 02.04.02.02.00 Unfortunately we need someone who speaks French(???) to understand how this works http://blast.darkphpbb.com/faq.php
    Judging by the contents of this file, it is an operating system of it's own including keyboard, mouse and a lot of debugging information. We need to find out more about the BLAST Kernel and this partition.


    Samsung Proprietary partitions SBL1,2,3
    Overall I'm not entirely familiar with this new 3 SBL setup. If someone could help me out, that would be great. This 3 SBL setup looks like they tried to adapt (slopily) their IBL+PBL+SBL setup to the Qualcomm and added overhead.

    op2=sbl1
    This block is signed by Samsung, we will not be able to modify it.
    Some Strings we expect to see on UART are:

    0p3=sbl2
    This block is signed by Samsung, we will not be able to modify it.

    Some of the strings we may see over UART are:
    Code:
    RPM loading is successful.
    cancel RPM loading!
    SBL2, End
    SBL2, Delta
    .sbl2_hw.c
    sbl2_hw_init, Start
    sbl2_hw_init, Delta
    sbl2_hw_init_secondary, Start
    h/w version : %d
    sbl2_hw_init_secondary, Delta
    .SBL2, Start
    scatterload_region & ram_init, Start
    .scatterload_region & ram_init, Delta
    .sbl2_mc.c
    sbl2_retrieve_shared_info_from_sbl1, Start
    .sbl2_retrieve_shared_info_from_sbl1, Delta

    0p4=sbl3
    This block is signed by Samsung, we will not be able to modify it.

    Possibly useful information:
    SVC: R1-R14
    FIQ:R13-R14
    IRQ:R13-R14
    UND:R13-R14
    ABT:R13-R14
    SYS:R13-R14

    This block appears to be a full OS of its own. I'm not sure of its purpose.

    op5= aboot
    This block is signed by Samsung, we will not be able to modify it

    This block contains HTML information. It would appear that it is possible to put the device into a mode where it will provide a webserver which displays state information.

    This block appears to be a complete operating system

    This block contains the Loke Daemon which communicates with Odin3.


    0p6= rpm
    This block is signed by Samsung we will not be able to modify it

    0p7= boot
    This is the kernel. There are several things we can do here... I belive this package itself is not signed, but the zImage itself is... here is the bootimg.cfg file

    Code:
    [email protected]:~/Desktop/VZWGS3$ cat ./bootimg.cfg 
    bootsize = 0xa00000
    pagesize = 0x800
    kerneladdr = 0x80208000
    ramdiskaddr = 0x81500000
    secondaddr = 0x81100000
    tagsaddr = 0x80200100
    name = 
    cmdline = console=null androidboot.hardware=qcom user_debug=31

    It may be possible to use that cmdline variable as an exploit.




    0p8= tzTrust Zone
    0p9= pad
    0p10= param -boot mode parameters - this could be a potential exploitation point.
    0p11= efs -serial numbers
    I've honestly got no clue about most of the following partitions.
    0p12= modemst1
    0p13= modemst2
    0p14= system - Android stuff
    0p15= userdata - App Stuff
    0p16= persist
    0p17= cache - Storage for updates
    0p18= recovery - recovery partition
    0p19= fota
    0p20= backup
    0p21= fsg
    0p22= ssd
    0p23= grow

    External UART log from initial power up:
    Code:
    [1630] AST_POWERON
    [    0.000000] heap->name mm, mb->start c0000000
    [    0.000000] Reserving memory at address ea000000 size: 100000
    [    0.000000] sec_dbg_setup: [email protected]
    [    0.000000] sec_dbg_setup: secdbg_paddr = 0x88d90004
    [    0.000000] sec_dbg_setup: secdbg_size = 0x40000
    [    0.000000] etb_buf_setup: [email protected]
    [    0.000000] etb_buf_setup: secdbg_paddr = 0x8fffb9c0
    [    0.000000] etb_buf_setup: secdbg_size = 0x4000
    [    0.174515] rdev_init_debugfs: Error-Bad Function Input
    [    0.174881] AXI: msm_bus_fabric_init_driver(): msm_bus_fabric_init_driver
    [    0.176957] sec_debug_init: enable=0
    [    0.177475] ec_debug_nit: restrt_reason: 0xdf0085c
    [    .216358] msm8960_iit_cam:292]settingdone!!
    [    0.25006] i2c 2c-14: Inalid 7-bi I2C addrss 0x00
        0.25237] i2c ic-14: Can' create evice at x00
    [   0.252220]i2c i2c-1: Failed o registeri2c clien cmc624 t 0x38 (-6)
    [    .252250] 2c i2c-19:Can't crete deviceat 0x38
        0.25433] rdevinit_debufs: Error-ad Functin Input
        0.25222] max892 19-006: DVS mode disabledbecause VD0 and VI1 do not ave prope control.
    [    0.79536] ms_etm msm_tm: ETM tacing is ot enable beacaussec_debug s not enaled!
    [   0.284449 smd_chanel_probe_orker: alocation tble not iitialized
                                                                      [    0.38766] pm_untime: fil to wak up
    [   0.362032]hdmi_msm dmi_msm.1 externalcommon_stte_create sysfs grup de39e68                                                                   
    [    0362673] Iside writback_drivr_init                                                                                                         
    [   0.36275] Insidewritebackprobe                                                                                                               
    [    1.244803] TZCOM: unable to get bus clk                                                                                                     
    [    1.431680] cm36651_setup_reg: initial proximity value = 3                                                                                   
    [    1.549671] msm_otg msm_otg: request irq succeed for otg_power                                                                               
    [    1.566702] mms_ts 3-0048: [TSP] ISC Ver [0xbb] [0x20] [0x20]                                                                                
    [    1.571341] mms_ts 3-0048: [TSP] fw is latest. Do not update.                                                                                
    [    1.583488] [__s5c73m3_probe:3818] S5C73M3 probe                                                                                             
    [    1.587089] [s5c73m3_sensor_probe_cb:3793] Entered                                                                                           
    [    1.591942] [s5c73m3_i2c_probe:3675] Entered                                                                                                 
    [    1.596123] [s5c73m3_init_client:3381] Entered                                                                                               
    [    1.600579] [s5c73m3_i2c_probe:3695] Exit                                                                                                    
    [    1.604608] [s5c73m3_sensor_probe:3726] Entered                                                                                              
    [    1.609095] [s5c73m3_spi_init:226] Entered                                                                                                   
    [    1.613154] [s5c73m3_spi_probe:191] Entered                                                                                                  
    [    1.617335] [s5c73m3_spi_probe:201] s5c73m3_spi successfully probed                                                                          
    [    1.623561] [s5c73m3_sensor_probe :  3749] Probe_done!!                                                                                      
    [    1.672638] mmc0: No card detect facilities available                                                                                        
    [    1.682984] aat1290a_led_probe : Probe                                                                                                       
    [    1.693850] msm_soc_platform_init                                                                                                            
    [    1.697298] msm_afe_afe_probe                                                                                                                
    [    1.843064] msm_asoc_pcm_new                                                                                                                 
    [    1.849748] msm_asoc_pcm_new                                                                                                                 
    [    2.023134] set_dload_mode <1> ( c00176d4 )                                                                                                  
    [    2.052220] cypress_touchkey 16-0020: Touchkey FW Version: 0x06                                                                              
    [    2.123851] init: /init.qcom.rc: 466: invalid command '/system/bin/log'                                                                      
    [    2.129620] init: /init.qcom.rc: 573: ignored duplicate definition of service 'sdcard'                                                       
    [    2.137402] init: /init.qcom.rc: 586: ignored duplicate definition of service 'ftm_ptt'                                                      
    [    2.145490] init: /init.target.rc: 73: ignored duplicate definition of service 'thermald'                                                    
    [    2.154677] init: could not open /dev/keychord                                                                                               
    [    2.239951] init: Device Encryption status is (0)!!                                                                                          
    [    2.243705] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p15 (ext4):::::                                                               
    [    2.251823] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p15                                                  
    [    2.588921] init: [disk_config] ext_check ->ok                                                                                               
    [    2.611597] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p17 (ext4):::::                                                               
    [    2.617762] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p17                                                  
    [    2.655333] init: [disk_config] ext_check -> ok                                                                                              
    [    2.664947] init: [disk_config] :::: fsck -> /dev/block/mmcblk0p11 (ext4):::::                                                               
    [    2.671081] init: [disk_config] ext_check -> /system/bin/e2fsck -v -y /dev/block/mmcblk0p11                                                  
    [    2.704532] init: [disk_config] ext_check -> ok                                                                                              
    [    3.259056] init: cannot find '/system/etc/install-recovery.sh', disabling 'flash_recovery'                                                  
    [    3.270471] init: cannot find '/system/bin/dmbserver', disabling 'dmb'

    External UART log from battery-pull and reinsert
    Code:
    [1630] AST_POWERON
    [    0.000000] heap->name mm, mb->start c0000000
    [    0.000000] Reserving memory at address ea000000 size: 100000
    [    0.000000] sec_dbg_setup: [email protected]
    [    0.000000] sec_dbg_setup: secdbg_paddr = 0x88d90004
    [    0.000000] sec_dbg_setup: secdbg_size = 0x40000
    [    0.000000] etb_buf_setup: [email protected]
    [    0.000000] etb_buf_setup: secdbg_paddr = 0x8fffb9c0
    [    0.000000] etb_buf_setup: secdbg_size = 0x4000
    [    0.174484] rdev_init_debugfs: Error-Bad Function Input
    [    0.174851] AXI: msm_bus_fabric_init_driver(): msm_bus_fabric_init_driver
    [    0.176926] sec_debug_init: enable=0
    [    0.177445] sc_debug_iit: restat_reason  0xdf0086c
    [    0216206] [sm8960_int_cam:299]setting one!!
    [   0.217915 select_req_plan:ACPU PVS:Nominal
        0.25206] i2c ic-14: Invaid 7-bit 2C addres 0x00
    [   0.25207] i2c i2-14: Can'tcreate deice at 0x0
    [    0252250] 2c i2c-19 Failed t register 2c clientcmc624 at0x38 (-16
    [    0252250] ic i2c-19: an't creae device t 0x38
    [   0.25243] rdev_iit_debugs: Error-Bd Functio Input
    [   0.25292] max895 19-0060:DVS modesdisabled ecause VI0 and VID do not hve propercontrols.
                                                                                               [    0.29536] msmetm msm_em: ETM trcing is nt enable!
    [    0.35797] pm_rntime: fal to wakeupllcation tale not intialized
    [    .362093] dmi_msm hmi_msm.1:external_ommon_stae_create:sysfs grop de39e60                                                                   
    [    0.62734] Inide writeack_driverinit                                                                                                         
    [   0.36285] Inside riteback_robe                                                                                                               
    [    1.244803] TZCOM: unable to get bus clk




    possible exploitations
    Possible entry point MODEM - Someone with a JTAG setup test viability of modifying a single byte on /dev/block/mmcblk0p1
    Possible entry point PARAMS - Samsung stores their boot parameters in PARAMS partition. It may be possible to modify PARAMS for insecure boot
    Possible entry point BOOT - Modify CMDLINE parameter to load information from another location.
    Possible entry point BOOT - We may be able to shove an insecure bootloader into memory, boot into that, and then use the recovery partition as our kernel partition. Bauwks 2nd U-Boot. U-Boot is available for the Exynos 4412, we need to find one for Qualcomm.
    Possible entry point SYSTEM - It may be possible to use a 2nd init hack from this partition to load custom kernels into memory and reboot the kernel.


    Current tasks
    What do all of these partitions do?
    Do we have a SDCard based recovery?
    Where can we find an Odin3 CSC Flash?
    Testing methods above is required
    96
    I have heard, but do not know, that there may be plans to get one of the developer phones into Adam's hands to extract from. That may provide insight into how to disable Qualcomm Secure Boot no? Anyone care to shed some light on if this is still planned or not? Thanks

    I don't need another device. I want all of the partitions from a developer device and I'd like to work with someone who has one. Remote access via "WirelessADB" and the device set to be in the "DMZ" of a router would be sufficient for all tests I would need to do.

    Just as an update, I'm slowly getting back to work. For those who were wondering, I packed up everything and moved. I have my stuff 90% set up. I'm just getting back on it. I'm working on compiling all of the Verizon GS3 exploits into a single CASUAL one-click package. Root, recovery, Busybox, Basic Hacking Tools.

    Once I've got a CASUAL package put together I'll go through and read this thread again from start to finish and figure out what needs work... my mind is totally off-topic right now after a move. Time to get back to work. I hope to have some big news at the end of next week.
    85
    It's been a few days so I wanted to give an update on the signature check on boot.img

    As has been previously guessed, everything important in boot.img is included in the signature check

    page_size is always 0x800 since we're using emmc boot

    hash_size = 0x800 (read the first page with the boot_img_header)
    hash_size += page_size * ((page_size + ramdisk_size - 1) / page_size)
    hash_size += page_size * ((page_size + kernel_size - 1) / page_size)
    hash_size += page_size * ((page_size + second_size - 1) / page_size)

    For the stock boot.img, this should come out to be 0x573000, so the first 0x573000 bytes in boot.img are checked.

    These bytes are then SHA1 hashed and passed to the verification function

    After hash_size bytes is a series of 0x100 byte blocks that will be passed to the verification function (img_sig_data parameter below)

    The verification function uses the following structure

    Code:
    struct sig_ctx_t {
    	int count;
    	int seed[65];
    	int subcheck_seed[64]; // possibly a modulus
    }

    This sig_ctx is located in aboot.img at file offset 0x12642C in VRALF2 and VRALG1 (It'll start with bytes 0x40, 0x00, 0x00, 0x00)

    I've cleaned up the first function a bit from what IDA/Hex-Rays spit out, but the second function I haven't simplified as much

    Code:
    int signature_check_data(sig_ctx_t *sig_ctx, char *img_sig_data, signed int signature_len, char *sha1_of_contents) {
    
    	int* img_ofs_0x100 = (int*)(img_sig_data + 0x100);
    	int* img_ofs_0x200 = (int*)(img_sig_data + 0x200);
    	int* img_ofs_0x300 = (int*)(img_sig_data + 0x300);
    	int* img_ofs_0x400 = (int*)(img_sig_data + 0x400); // Temporary storage
    
    	// Copy 0x0 block to 0x100
    	memcpy(img_ofs_0x100, &img_sig_data[0], signature_len);
    
    	// ofs_0x200 is filled with byte-swapped ints from img_ofs_0x100
    	for (int i = 0; i < sig_ctx->count; i++) {
    		img_ofs_0x200[i] =  htonl(img_ofs_0x100[sig_ctx->count - 1 - i]);
    	}
    
    	// subcheck(sig_block *block, int *output, int *input1, int *input2)
    	// multiplication maybe?
    	signature_subcheck(sig_ctx, img_ofs_0x300, img_ofs_0x200, sig_ctx->subcheck_seed);
    	signature_subcheck(sig_ctx, img_ofs_0x400, img_ofs_0x300, img_ofs_0x300);
    	signature_subcheck(sig_ctx, img_ofs_0x300, img_ofs_0x400, img_ofs_0x200);
    
    	if ( sig_ctx->count )
    	{
    		count_minus_1 = sig_ctx->count - 1;
    		v18 = img_ofs_0x300[sig_ctx->count - 1];
    		v19 = sig_ctx->seed[sig_ctx->count]; // seed[64]
    		// v19 = *(&sig_ctx->count + sig_ctx->count + 1);
    		if ( v18 >= v19 )
    		{
    			if ( v18 == v19 )
    			{
    				for (int i = 0; i < sig_ctx->count; i++) {
    					int v22 = img_ofs_0x300[sig_ctx->count - 1 - i];
    					int v23 = sig_ctx->seed[sig_ctx->count - 1 - i];
    					if (v22 < v23) {
    						goto LABEL_18
    					}
    				}
    			}
    			if ( sig_ctx->count > 0 )
    			{
    				int carry = 0;
    				for (int i = 0; i < sig_ctx->count; i++) {
    					uint64 temp = img_ofs_0x300[i] - (uint64)sig_ctx->seed[i + 1];
    					img_ofs_0x300[i] = img_ofs_0x300[i] - sig_ctx->seed[i + 1] + carry;
    					carry = (int)(temp >> 32); // get high 32 bits
    				}
    			}
    		}
    
    		LABEL_18:
    		// Store the calculation back into img_ofs_0x100
    		for (int i = 0; i < sig_ctx->count; i++) {
    			int val = img_ofs_0x300[sig_ctx->count - 1 - i];
    			char* dest = &img_ofs_0x100[i];
    
    			dest[0] = (val & 0xFF000000) >> 24;
    			dest[1] = ((val & 0x00FF0000) >> 16) & 0xFF;
    			dest[2] = ((val & 0x0000FF00) >> 8) & 0xFF;
    			dest[3] = (val & 0xFF);
    		}
    
    		if (memcmp(img_ofs_0x100, sig_check_compare_result, 236)) // sig_check_compare_result is a char[236] with the first 2 bytes 0x00, 0x01, and the rest 0xFF
    			return 0;
    
    		if (signature_len > 236) {
    			if (memcmp(&img_ofs_0x100[236], sha1_of_contents, signature_len - 236)) // 256-236 = 20
    				return 0;
    
    			// Signature passed
    			return 1;
    		}
    	}
    	return 0;
    }


    Here's the subcheck function, it looks like arbitrary-precision math, possibly mulmod

    Code:
    void __fastcall signature_subcheck(sig_ctx_t *sig_data, int *output, int *input1, int *input2)
    {
      int v5; // [email protected]
      int count; // [email protected]
      unsigned __int64 v7; // [email protected]
      unsigned __int64 v8; // [email protected]
      int inner_index; // [email protected]
      int block1_pos; // [email protected]
      int v11; // [email protected]
      __int64 v12; // [email protected]
      int v13; // [email protected]
      unsigned __int64 v14; // [email protected]
      int v15; // [email protected]
      int v16; // [sp+18h] [bp-48h]@6
      unsigned int v17; // [sp+1Ch] [bp-44h]@6
      int outer_index; // [sp+2Ch] [bp-34h]@5
    
      if ( sig_data->count > 0 )
      {
        v5 = 0;
        do
        {
          output[v5++] = 0;                         // this do while is just memset(output, 0, 4 * sig_data->count)
          count = sig_data->count;
        }
        while ( sig_data->count > v5 );
        if ( count > 0 )
        {
          outer_index = 0;
          do
          {
            v16 = input1[outer_index];
            v7 = (unsigned int)v16 * (unsigned __int64)(unsigned int)*input2 + (unsigned int)*output;// v7 = input1[outer_index] * (uint64)input2[0] + output[0]
            v17 = sig_data->seed[0] * v7;
            v8 = sig_data->seed[1] * (unsigned __int64)v17 + (unsigned int)v7;
            if ( count <= 1 )
            {
              block1_pos = 1;
            }
            else
            {
              inner_index = 0;
              block1_pos = 1;
              do
              {
                v7 = (unsigned int)v16 * (unsigned __int64)(unsigned int)input2[block1_pos]
                   + (unsigned int)output[block1_pos]
                   + HIDWORD(v7);
                v8 = sig_data->seed[inner_index + 2] * (unsigned __int64)v17 + HIDWORD(v8) + (unsigned int)v7;
                ++block1_pos;
                output[inner_index] = v8;
                ++inner_index;
              }
              while ( block1_pos < sig_data->count );
            }
            output[block1_pos - 1] = HIDWORD(v8) + HIDWORD(v7);
            if ( (HIDWORD(v8) + (unsigned __int64)HIDWORD(v7)) >> 32 )
            {
              if ( sig_data->count <= 0 )
                return;
              v11 = 0;
              v12 = 0LL;
              v13 = 0;
              do
              {
                v14 = (unsigned int)output[v11] - (unsigned __int64)sig_data->seed[v11 + 1];
                v15 = output[v11] - sig_data->seed[v11 + 1];
                output[v11] = output[v11] - sig_data->seed[v11 + 1] + v12;
                count = sig_data->count;
                ++v13;
                ++v11;
                v12 = (signed int)((__PAIR__(HIDWORD(v14), v15) + v12) >> 32);
              }
              while ( v13 < sig_data->count );
            }
            else
            {
              count = sig_data->count;
            }
            ++outer_index;
          }
          while ( outer_index < count );
        }
      }
    }


    The goal is to make it so that after all the calculations the 256 byte block located at img_sig_data+0x100 has the contents 0x00, 0x01, 0xFF * 236, and then the sha1 of our boot.img

    I'm in the middle of moving at the moment, so I don't have as much time as I would like to look at this right now, but that should clear up in a few days.

    Also, if there's any interest I can post a guide on how to get the bootloader files loaded into IDA for analysis. Some knowledge of ARM assembly would be required though.

    EDIT:

    In other news, I found what keeps resetting the 16 byte encrypted romtype in param.img. It's libcordon.so, which is from /system/app/SysScope.apk (it'll also be copied to /system/lib/libcordon.so). It's using quite a few checks to see if you've modified your system.

    There's an adb scanner, checking to see if you've changed the ro.secure or ro.debuggable props.

    The root process scanner checks running processes and returns true if any are found running as root that are not one of:
    "debuggerd", "init", "installd", "servicemanager", "vold", "zygote", "netd", "ueventd", "dock_kbd_attach", "pppd", "pppd_runner", "mpdecision", "thermald", "hdmid", "sec_keyboard", "seccmmond", "mfsc", "mfdp"

    There's also a partition check, kernel checker, su scanner, and a file scanning mechanism using data from a sqlite db

    So to completely remove the Samsung custom screen on bootup and 5 second delay you'd need to disable the SysScope.apk, then encrypt and write the 16 bytes yourself using 0xFF000000 as the first int to mark yourself as official
    70
    A gentleman named Lee contacted me via email. He said he has 0 posts so he could not post in here. This post contains his email to me. I am not wrapping it in quotes because quotes are destroyed in future posts. This is literally the best development we've had in this thread.



    ------email from Lee------
    I've been looking at the bootloader in aboot.img the past day or so and wanted to contribute what I know about the param.img partition and how it's used. I've been following the thread at xda, but since my account has 0 posts I can't actually post this in that thread.

    Please note these are a little rough around the edges, just things I jotted down while reverse engineering.

    param.img Structure

    At offset 0 there's an 88 byte structure I've called the header

    struct param_header {
    int status; // need to investigate more. some relationships between this and boot modes. 4 == firmware error int unk_04; // haven't seen this used anywhere int unk_08; // haven't seen this used anywhere int emmc_checksum_attempted; int emmc_checksum_ok; int nvdata_backup; // says whether we have a backup of modemst1 in "fsg" partition and a backup of modemst2 in "backup" partition?
    int unk_18[16]; // haven't seen this used anywhere };

    status (NEEDS WORK):
    1 = ?
    2 = boot_mode 3?
    3 = recovery?
    4 = boot_mode 1 - fastboot. displays "firmware update issue" image
    5 = boot_mode 4?


    at offset 0x900000 there's a structure controlling some debug variables

    struct param_debug {
    int debug_level;
    int unk_04; // 4 in dumps. haven't seen this used anywhere int unk_08; // 0 in dumps. haven't seen this used anywhere int emmc_checksum_attempted; // mirror of param_header.emmc_checksum_attempted
    int emmc_checksum_ok; // mirror of param_header.emmc_checksum_ok };

    About param_debug.debug_level:
    It has 3 possible values, and it changes some flags are passed to the kernel.
    DLOW is the default, but some features like ramdump mode only work on DMID or DHIG

    1. 0x574F4C44 (DLOW) - Low debug setting strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x4f4c");// OL strcat(boot_img_hdr->cmdline, " sec_debug.enable=0"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=0");

    2. 0x44494D44 (DMID) - Mid-level debugging strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x494d");// IM strcat(boot_img_hdr->cmdline, " sec_debug.enable=1"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=0");

    3. 0x47494844 (DHIG) - Full debugging
    strcat(boot_img_hdr->cmdline, " androidboot.debug_level=0x4948");// IH strcat(boot_img_hdr->cmdline, " sec_debug.enable=1"); strcat(boot_img_hdr->cmdline, " sec_debug.enable_user=1"); strcat(boot_img_hdr->cmdline, " slub_debug=FPUZ");

    Check drivers/misc/sec_misc.c for what these values do for the kernel


    At offset 0x9FFC00 (sizeof(param.img) - 0x400 is how the offset is calculated by the BL):
    Here are 16 bytes unique to each device, and they are part of what determines whether or not you have a custom rom.

    It's AES128 encrypted using a key made from the emmc's psn and some static data

    Key generation:
    First, the 4byte psn is expanded to 8 bytes

    char first_half[14];
    snprintf(first_half, 13, "%08x", mmc_get_psn()); memcpy(aes_initial_key, first_half, 8);

    The second half is calculated based on all static data

    char custom_check_index_shuf_table[] = { 1, 3, 2, 4, 5, 1, 0, 4, 4, 5, 4, 0 }; char custom_check_table[] = { 0x40, 0x74, 0x25, 0x61, 0x21, 0x74, 0x70, 0x62, 0x62, 0x24, 0x33, 0x5E }; char romtype_enc_key_buf[32];

    char* custom_check_shuffle_calc(signed int always_199, int count) { int out_index; // [email protected] int last_index; // [email protected] int odd_index; // [email protected] int table_index; // [email protected] char table_value;

    if ( count <= 0 )
    {
    out_index = 0;
    }
    else
    {
    out_index = 0;
    last_index = 0;
    do
    {
    odd_index = always_199 & 1;
    always_199 >>= 1;
    table_index = odd_index + 2 * last_index; table_value = custom_check_table[table_index]; last_index = custom_check_index_shuf_table[table_index];
    romtype_enc_key_buf[out_index++] = table_value; } while ( out_index != count ); } romtype_enc_key_buf[out_index] = 0; return romtype_enc_key_buf; }

    This function is used like this (the parameters are always 199 and 8 in the vzw aboot):
    char* second_half = custom_check_shuffle_calc(199, 8); memcpy(&aes_initial_key[8], second_half, 8);

    Now we have 16 bytes in aes_initial_key, but it's shuffled again with the following function

    char custom_check_final_index_table[] = { 0, 4, 5, 0xD, 3, 8, 0xE, 9, 0xA, 2, 1, 7, 0xB, 6, 0xC, 0xF }; void custom_check_shuffle_final_key(char *iv, char *final) { int v2; // [email protected] int v5; // [email protected]

    v2 = 0;
    do
    {
    final[custom_check_final_index_table[v2]] = iv[v2];
    v2++;
    }
    while ( v2 != 16 );
    v5 = 0;
    do
    {
    final[custom_check_final_index_table[v5]] = iv[v5] ^ final[v5];
    v5++;
    }
    while ( v5 != 16 );
    }

    char aes_final_key[16];
    custom_check_shuffle_final_key(aes_initial_key, aes_final_key);

    This final key should be able to decrypt the 16 bytes

    The first 4 decrypted bytes cast to an int will be 0xFF000000 if you're running an official rom, or 0xEE000000 if you've flashed something custom If it's 0xEE000000 then you will be shown the "Custom" boot screen with the padlock on it, and it also causes a call to mdelay(5000) before actually booting the kernel.
    I've also seen 0xCC000000 mentioned in debug prints, causing it to print the device status as "Scanning" instead of "Official" or "Custom"


    Unfortunately this doesn't seem to help much with the boot.img check, but I've found where that is and am reversing it now.


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    DDI Data
    Here's where the values like the flash count are stored (sometimes this might be called triangle state?) It's stored at 0x3FFE00 on the mmc

    struct ddi_data {
    int magic; // must be 0x12340012
    int custom_flash_count;
    int odin_count;
    int binary_type; // 0 = samsung official, 1 = custom, 2 = "Unknown"
    char model_name[16];
    int rom_type; // this is the first 4 bytes of the decrypted 16 bytes in the param partition. 0xFF000000 = samsung, 0xEE000000 = custom }


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    Reboot Reason

    Values and effects for the reboot reason stored at 0x2A03F65C

    0x12345671 - ?
    0x12345678 - Normal mode


    0x77665500 - FASTBOOT_MODE. displays "downloading" boot image
    0x77665501 - ? seen checked but haven't found it used anywhere
    0x77665502 - RECOVERY_MODE. sets param_header.state to 3
    0x77665503 - sets param_header.state to 4. haven't seen it actually used

    0x77665507 - display the "not authorized" picture

    if ((reason & ~0xF) == 0x77665510) then they're commands for manipulating the nvdata I wouldn't play around with these unless you really know what you're doing All of them reboot the device into the normal mode except 0x77665515

    0x77665511 - copy modemst1 to fsg partition and copy modemst2 to backup partition. sets param_header.nvdata_backup to 1
    0x77665512 - copy fsg to modemst1 and copy backup to modemst2. checks to ensure param_header.nvdata_backup=1 first
    0x77665514 - erase fsg and backup partitions. clears param_header.nvdata_backup
    0x77665515 - same as 0x77665511 but then reboots the device into RECOVERY_MODE


    0x776655EE - RAMDUMP_MODE (only valid if param_debug.debug_level is DMID/DHIG)


    0xABCD4F4C - set param_debug.debug_level to DLOW 0xABCD494D - set param_debug.debug_level to DMID
    0xABCD4948 - set param_debug.debug_level to DHIG

    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    boot_type INCOMPLETE
    1 = fastboot
    2 = ramdump mode
    3 = recovery. resets param_debug
    4 = ?


    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    USB Flags INCOMPLETE

    0xF00 - jig mask
    0x100 - put the device into factory mode
    0x400 - change "console" boot parameter to "console=ttyHSL0,115200,n8%s" where %s is replaced by whatever was originally after "console="

    ----------------------------------------------------------------------------------------------------------------------------------------------------------------

    ODIN

    In addition to the ODIN/LOKE handshake sequence I saw in heimdall, there are 2 more in the S3.
    Send "FPGM" and you should get a response of "OK". It functions exactly as the ODIN/LOKE sequence.
    Send "ROOTING" and it responds with the current DDI data and terminates.

    -Lee