Need Some Info About Samsung Downgrade Via ISP - GSM-Forum

hitech care · 03-20-2020, 20:31

Hi Friend I Am Having A Query About Samsung Downgrade I Need Some Info About Procedures Or Hint For My Case..

Problem :- I Have Samsung J610F J6+ Handset With U5 Binary Actually Phone Have Copy Touch With U5 Binary Touch Not Work Need To Downgrade...

History :- Phone Have All Things Working Some XYZ Technicians From Market Installed U5 Binary But U4 Binary Is Latest Till Now For My Region...After He Flash Volte N Touch Issue Arrive..

What I Try To Solve :- 1st Flashing With OEM N FRP OFF With U4 Binary Gets Fail With Error Phone Having U5...Not Even Combination Allow To Flash U4...U5 Combination Not Available For Now...

Now With ISP I Try To Full Flash Using Write By Vendor Handset Dead...Then I Again Write Backup (Which I Was Taken Before) Handset On Then I Write Only System To Change My Binary To U4 (Easy JTAG Show U4 Build In Info) But In Download Mode Still Showing U5 (Flashing Again Fail Via Download Mode) So I Try Erase Whole Chip N Flash With U4 File N Write Security...Now Again On DLOAD..

So I Wanna Know Few Things About This..What If I Erase N Write Factory File Only Not Security Sector Can I Repair Security Later Using Backup EFS Or Dump Or Anything Else...

2n How Can I Change Download Mode Binary Status As In Earlier Android Ver When U Write System It Allow To Flash...Phone Having Android 9.0...

3rd Can We Extract Cert Data From Dump For This Phone....

Any Guidance Or Help Will Be Appreciated...

layder · 03-21-2020, 11:42

Samsung device can't start with old boots (U5->U4, etc)

hitech care · 03-21-2020, 11:54

Quote:

Originally Posted by layder

Samsung device can't start with old boots (U5->U4, etc)

What If I Erase Whole Chip N Write U4 Then Also It Won't Boot....?

ghr · 03-21-2020, 14:49

only phone can boot up with lateat binaray if u used any old binaray the no

:confuse d:

layder · 03-22-2020, 10:35

Quote:

Originally Posted by hitech care

What If I Erase Whole Chip N Write U4 Then Also It Won't Boot....?

protection at CPU
erase can't help you

MiRoOo · 03-24-2020, 12:27

As sir layder said, protection lies in CPU not only in eMMC.
There're some areas in SoC that has OTP specification which means it works like a Fuse and these areas are responsible for software images verification, specifically SBL (XBL).
For example, Xiaomi Redmi Note 5 (whyred) with Qualcomm CPU.
Antirollback (ARB) protection that prevents us from Downgrade, stored inside CPU in a specific area called QFPROM.
If device has ARB 3 that means not only eMMC knows about but also CPU.
And so, erasing eMMC and reprogramming it with a lower ARB won't help at all as CPU will always want ARB 3 firmware in order to boot.
The idea here is to access QFPROM and overwrite it's data or erase it and this is actually.... Impossible!.

for more information, read here and here

br, mshib0

hardnsoft67 · 03-26-2020, 15:01

Untick repartition option while flashing be careful.downgrade will work

hardnsoft67 · 03-26-2020, 15:04

first flash u4 combination by isp.be careful to untick repartition.if u dont untick phone will be dead.not need to erase chip

after flash .put phone in download mode and flash u4 combination by odin thats it.

yuresh · 03-27-2020, 15:07

Quote:

Originally Posted by hardnsoft67

first flash u4 combination by isp.be careful to untick repartition.if u dont untick phone will be dead.not need to erase chip

after flash .put phone in download mode and flash u4 combination by odin thats it.

This solution has been researched?

03-20-2020, 20:31	#1 (permalink)
hitech care No Life Poster Join Date: Nov 2012 Location: Ek India Happy Wala.. :-) Posts: 2,828 Member: 1834832 Status: Offline Thanks Meter: 1,450	Need Some Info About Samsung Downgrade Via ISP Hi Friend I Am Having A Query About Samsung Downgrade I Need Some Info About Procedures Or Hint For My Case.. Problem :- I Have Samsung J610F J6+ Handset With U5 Binary Actually Phone Have Copy Touch With U5 Binary Touch Not Work Need To Downgrade... History :- Phone Have All Things Working Some XYZ Technicians From Market Installed U5 Binary But U4 Binary Is Latest Till Now For My Region...After He Flash Volte N Touch Issue Arrive.. What I Try To Solve :- 1st Flashing With OEM N FRP OFF With U4 Binary Gets Fail With Error Phone Having U5...Not Even Combination Allow To Flash U4...U5 Combination Not Available For Now... Now With ISP I Try To Full Flash Using Write By Vendor Handset Dead...Then I Again Write Backup (Which I Was Taken Before) Handset On Then I Write Only System To Change My Binary To U4 (Easy JTAG Show U4 Build In Info) But In Download Mode Still Showing U5 (Flashing Again Fail Via Download Mode) So I Try Erase Whole Chip N Flash With U4 File N Write Security...Now Again On DLOAD.. So I Wanna Know Few Things About This..What If I Erase N Write Factory File Only Not Security Sector Can I Repair Security Later Using Backup EFS Or Dump Or Anything Else... 2n How Can I Change Download Mode Binary Status As In Earlier Android Ver When U Write System It Allow To Flash...Phone Having Android 9.0... 3rd Can We Extract Cert Data From Dump For This Phone.... Any Guidance Or Help Will Be Appreciated...

03-21-2020, 14:49	#4 (permalink)
ghr No Life Poster Join Date: Apr 2010 Location: chishtian Posts: 1,335 Member: 1282787 Status: Offline Sonork: 100.1673491 Thanks Meter: 307	only phone can boot up with lateat binaray if u used any old binaray the no:confuse d:

03-21-2020, 11:42	#2 (permalink)
layder Product Supporter Join Date: Jun 2002 Location: Belarus Age: 47 Posts: 3,187 Member: 13148 Status: Offline Thanks Meter: 2,948	Samsung device can't start with old boots (U5->U4, etc)

03-24-2020, 12:27	#6 (permalink)
MiRoOo No Life Poster Join Date: Sep 2007 Location: Gizah/Egypt Age: 33 Posts: 660 Member: 594436 Status: Offline Sonork: 100.1657777 Thanks Meter: 952	As sir layder said, protection lies in CPU not only in eMMC. There're some areas in SoC that has OTP specification which means it works like a Fuse and these areas are responsible for software images verification, specifically SBL (XBL). For example, Xiaomi Redmi Note 5 (whyred) with Qualcomm CPU. Antirollback (ARB) protection that prevents us from Downgrade, stored inside CPU in a specific area called QFPROM. If device has ARB 3 that means not only eMMC knows about but also CPU. And so, erasing eMMC and reprogramming it with a lower ARB won't help at all as CPU will always want ARB 3 firmware in order to boot. The idea here is to access QFPROM and overwrite it's data or erase it and this is actually.... Impossible!. for more information, read here and here br, mshib0

03-26-2020, 15:01	#7 (permalink)
hardnsoft67 Freak Poster Join Date: Nov 2015 Posts: 228 Member: 2489055 Status: Offline Thanks Meter: 71	Untick repartition option while flashing be careful.downgrade will work

03-26-2020, 15:04	#8 (permalink)
hardnsoft67 Freak Poster Join Date: Nov 2015 Posts: 228 Member: 2489055 Status: Offline Thanks Meter: 71	first flash u4 combination by isp.be careful to untick repartition.if u dont untick phone will be dead.not need to erase chip after flash .put phone in download mode and flash u4 combination by odin thats it.