Develop Bugs

Roto Backup! UPDATED Dec 5 2010

I've been trying to recreate a flashable firmware based on the stock TMobile flash dumps and I have complete success.
Heres how to save your current firmware. It will be saved with all apps and settings except for whats on /sdcard.
I recommend reseting to defaults using "Settings->Privacy->Factory data reset" if you want to give these files to someone else to build a flashable rom for you. That will delete all your personal information.
Note: I just backed up a completely setup AT&T Tab, with tons of apps and customizations and restored it to my stock T-Mobile Tab, perfectly! Every app works, home screen is setup perfect, everything!
Effectively this is equivalent to a nandroid backup.
I'll call it "Roto Backup"!
Code:
mkdir backup
cd backup
adb shell su -c "dd if=/dev/block/bml1 of=/sdcard/boot.bin bs=4096"
adb shell su -c "dd if=/dev/block/bml2 of=/sdcard/pit.pit bs=4096"
adb shell su -c "dd if=/dev/block/stl3 of=/sdcard/efs.rfs bs=4096"
adb shell su -c "dd if=/dev/block/bml4 of=/sdcard/Sbl.bin bs=4096"
adb shell su -c "dd if=/dev/block/stl6 of=/sdcard/param.lfs bs=4096"
adb shell su -c "dd if=/dev/block/bml7 of=/sdcard/zImage bs=4096"
adb shell su -c "dd if=/dev/block/stl9 of=/sdcard/factoryfs.rfs bs=4096"
adb shell su -c "dd if=/dev/block/stl10 of=/sdcard/dbdata.rfs bs=4096"
adb shell su -c "dd if=/dev/block/stl11 of=/sdcard/cache.rfs bs=4096"
adb shell su -c "dd if=/dev/block/bml12 of=/sdcard/modem.bin bs=4096"
adb shell su -c "tar -czvf /sdcard/data.tar.gz /data"
adb pull /sdcard/param.lfs .
adb pull /sdcard/zImage .
adb pull /sdcard/factoryfs.rfs .
adb pull /sdcard/dbdata.rfs .
adb pull /sdcard/cache.rfs .
adb pull /sdcard/modem.bin .
adb pull /sdcard/efs.rfs .
adb pull /sdcard/boot.bin .
adb pull /sdcard/Sbl.bin .
adb pull /sdcard/pit.pit .
adb pull /sdcard/data.tar.gz .
Note you will be prompted for superuser permissions on the Tabs LCD on every dd command.
If you don't have the tar command on your tab, install Busybox Installer from the market.
I just paste the above commands into my command shell window and when im done all the files are siting in my current (backup) directory.
Roto Restore:
First flash the data back:
Code:
adb push data.tar.gz /sdcard/data.tar.gz
adb shell su -c "tar -zxvf /sdcard/data.tar.gz"
adb reboot download
Now flash the dumps with Heimdall:
Code:
heimdall flash --kernel zImage --factoryfs factoryfs.rfs --modem modem.bin --cache cache.rfs --dbdata dbdata.rfs --param param.lfs
Of course you could tar the files right n the Tab and flash via Odin if you really want to:
Code:
adb shell
cd /sdcard
tar -cf mybackup.tar cache.rfs dbdata.rfs factoryfs.rfs modem.bin param.lfs zImage
exit
adb pull /sdcard/mybackup.tar .

Nice
This interesting work, im curious though, what is your ultimate goal?
You want a Tmo firmware dump? to what end?

alias_neo said:
This interesting work, im curious though, what is your ultimate goal?
You want a Tmo firmware dump? to what end?
Click to expand...
Click to collapse
The Tmo dump/restore is a test. I want a solid backup/restore and custom rom creation solution.

Fair enough. But is the custom recovery being developed (and progressing nicely) not a solid enough solution?

I won't know till its functional.

rotohammer said:
I won't know till its functional.
Click to expand...
Click to collapse
Do you not have other android devices? I know of none where it doesn't function. So there is no reason i wouldn't wait a little longer for this to be ported.

alias_neo said:
Do you not have other android devices? I know of none where it doesn't function. So there is no reason i wouldn't wait a little longer for this to be ported.
Click to expand...
Click to collapse
A nandroid backup of my rom isn't something I can post publicly on the net. Regardless, I need to create full custom roms that can be flashed using Odin and Heimdall.

rotohammer said:
A nandroid backup of my rom isn't something I can post publicly on the net. Regardless, I need to create full custom roms that can be flashed using Odin and Heimdall.
Click to expand...
Click to collapse
Exactly, you post update.zips and then people use clockwork to flash the full ROM. On device recovery is much better than Odin method and more accessible to noobs that have an aneurism when they see the Odin iterface.
As for dumping your ROM to customise, well, yes, either this way using dd or decrypt the Odin flash files.

Now we're talking:
http://forum.xda-developers.com/showthread.php?t=850995

It sounds like this guy is new to android and iz trying to reinvent the wheel
Sent from my SGH-T849 using XDA App

miketaylor00 said:
It sounds like this guy is new to android and iz trying to reinvent the wheel
Sent from my SGH-T849 using XDA App
Click to expand...
Click to collapse
No, it sounds like he's trying to do exactly what he says he's doing, and that is to recreate the base TMo firmware from DD dumps!
Why? So that if necessary he could return to complete stock if he wished, and because there is no stock TMo image available.
A Nandroid backup doesn't cut the mustard in this case.
Remember guys - just because you don't see a need for something, it doesn't mean that that need doesn't exist for others!
Regards,
Dave
P.S. If you'd read any of Rotohammers posts in these forums, and looked back over previous activity in other sections, you'd know that he's not new to Android at all!

foxmeister said:
No, it sounds like he's trying to do exactly what he says he's doing, and that is to recreate the base TMo firmware from DD dumps!
Why? So that if necessary he could return to complete stock if he wished, and because there is no stock TMo image available.
A Nandroid backup doesn't cut the mustard in this case.
Remember guys - just because you don't see a need for something, it doesn't mean that that need doesn't exist for others!
Regards,
Dave
P.S. If you'd read any of Rotohammers posts in these forums, and looked back over previous activity in other sections, you'd know that he's not new to Android at all!
Click to expand...
Click to collapse
I forgot entirely that the Tab some people have might be carrier customised, mines a generic one so I can flash any of the generic dumps to put it back to "stock".
So yes, a Tmo stock firmware is useful for you guys.

miketaylor00 said:
It sounds like this guy is new to android and iz trying to reinvent the wheel
Click to expand...
Click to collapse
Yes, I am new to Android but I don't enjoy reinventing the wheel.
Perhaps you can point me to the code that I'm re-inventing that you are obviously familiar with?
Thanks in advance!

rotohammer: I've been looking for the ways to dump the firmware like you are suggesting for the AT&T version, mainly because the only available dump is an older version that stock. So far all I've found is this from another post by you:
I would like to get various Vibrant radio dumps if someone would be so kind to do so. The command from adb shell is:
Code:
dd if=/dev/block/bml12 of=/sdcard/bml12.dump bs=4096
Lets discuss what we've tried in this thread.
Click to expand...
Click to collapse
The instructions seem straightforward enough for anyone who has used dd before. How were you able to ascertain the location of this (and other) pieces of the firmware? (Interested to know prior to trying to enable voice on my Tab by swapping modems and reflashing. I'm familiar with Samsung devices since I have a Captivate, but not too reassured that the newest firmware available to restore to is older than launch date.)

The instructions seem straightforward enough for anyone who has used dd before. How were you able to ascertain the location of this (and other) pieces of the firmware? (Interested to know prior to trying to enable voice on my Tab by swapping modems and reflashing. I'm familiar with Samsung devices since I have a Captivate, but not too reassured that the newest firmware available to restore to is older than launch date.)
Click to expand...
Click to collapse
The Tab follows the flash layout of other previous Samsung phones, so just google them, the info is out there. I stare at hexdumps to identify/prove what each partition contains, no big deal.
I feel that once some more official firmware is released all the need for reconstruction of dumps will eliminated.

Figured I'd chime in here from my experience, since I've gone through it with the Epic 4G....
The .rfs files and .lfs files won't restore with redbend... and don't touch bml1 and bml4... that's the boot.bin and sbl.bin... screwing with those can lead to brick...
Current roms for the Epic 4g use update-script or updater-script (different formats, updater-script requires update-binary. The scripts get flashed with clockworkmod... first, system is formatted, then the system files copied over, then permissions given to the files. The kernel is flashed using redbend, along with modem (ours require updater-scripts and a modem_delta file if not using odin).
I browse .rfs system images by first creating a /mnt folder on the sd card. With busybox, use the following command:
Code:
Busybox mount /sdcard/factoryfs.rfs /sdcard/mnt
[/card]
I've gotten the factoryfs.rfs from the stock tars...
Maybe this is reinventing the wheel, but maybe it'll help.
Sent from my SPH-D700 using Tapatalk

rotohammer said:
The Tab follows the flash layout of other previous Samsung phones, so just google them, the info is out there. I stare at hexdumps to identify/prove what each partition contains, no big deal.
I feel that once some more official firmware is released all the need for reconstruction of dumps will eliminated.
Click to expand...
Click to collapse
Gotcha. Thanks. So, for restores, do you use redbend_ua or does a simple reversal of the dd command work? (admittedly this is an area where I haven't quite dug into yet)

maniac3389 said:
Gotcha. Thanks. So, for restores, do you use redbend_ua or does a simple reversal of the dd command work? (admittedly this is an area where I haven't quite dug into yet)
Click to expand...
Click to collapse
You must use redbend_ua, Odin or Heimdall (theres others too). You can't write to these partitions with dd alone, although there is an app that allows you to use dd too.

DRockstar said:
Figured I'd chime in here from my experience, since I've gone through it with the Epic 4G....
The .rfs files and .lfs files won't restore with redbend... and don't touch bml1 and bml4... that's the boot.bin and sbl.bin... screwing with those can lead to brick...
Current roms for the Epic 4g use update-script or updater-script (different formats, updater-script requires update-binary. The scripts get flashed with clockworkmod... first, system is formatted, then the system files copied over, then permissions given to the files. The kernel is flashed using redbend, along with modem (ours require updater-scripts and a modem_delta file if not using odin).
I browse .rfs system images by first creating a /mnt folder on the sd card. With busybox, use the following command:
Code:
Busybox mount /sdcard/factoryfs.rfs /sdcard/mnt
[/card]
I've gotten the factoryfs.rfs from the stock tars...
Maybe this is reinventing the wheel, but maybe it'll help.
Sent from my SPH-D700 using Tapatalk[/QUOTE]
I'll give that a look, don't know why it didn't dawn on me to give a look at the ROMs for my Captivate again. I've looked inside an update.zip file before, but didn't really delve into the script inside.
As for the actual dumping of the images, when dumping the .rfs files, what's the difference between using, say, /dev/block/stl9 versus /dev/block/bml9? Will one work and not the other?
What I'd like to be able to do is dump a current stock AT&T ROM since the one posted is older (and possibly an engineering ROM from what I recall reading.)
My current resources are:
[URL="http://forum.xda-developers.com/wiki/index.php?title=Samsung_Galaxy_S_Series#Partitions"]http://forum.xda-developers.com/wiki/index.php?title=Samsung_Galaxy_S_Series#Partitions[/URL]
[URL="http://forum.xda-developers.com/showthread.php?t=794425&page=2"]http://forum.xda-developers.com/showthread.php?t=794425&page=2[/URL]
[URL="http://androidforums.com/behold-2-all-things-root/54424-creating-custom-roms-backups-odin.html"]http://androidforums.com/behold-2-all-things-root/54424-creating-custom-roms-backups-odin.html[/URL]
Click to expand...
Click to collapse

rotohammer said:
Why the failure?
Probably because the file systems were still mounted at the time the dumps were made, the zImage partition and the modem partition are not mounted at runtime.
Click to expand...
Click to collapse
Here is a thought, although I may be completely off base:
I noticed that you can access the ADB shell if you boot into stock recovery, perhaps you can mount the SD and dump a few more RFS images?

[Q] i747M no download/recovery after JTAG solution

For some reason the I747M.DLL does not work correctly and Im pretty sure about this. If you use the I747M.DLL you will not have Download Mode. I know how to fix this but need SBL1.MBN specifically from Claro PR Unit and Im 100% Sure this one will work in any other USA/Canada Versions. Then for the others SBL2,SBL3,TZ,RPL & ABOOT they are on the stock I747MUMBLL1. Some one can try to make debrick.img from a working I747M rooted with this instructions and also make a backup of .PIT cuz are not the same.
This is the Most Important a Backup of a Good/Working Unit SBL1.MBN, Phone has to be rooted to extract it.
su
dd if=/dev/block/mmcblk0p2 of=/sdcard/sbl1 bs=4096
This is the Second Most Important a Backup of a Good/Working Unit OUT.PIT file, Phone has to be rooted to extract it.
su
dd if=/dev/block/mmcblk0 of=/sdcard/out.pit bs=8 count=481 skip=2176
This is for make a Recovery SDC Card:
su
dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1M count=128
I already see a lot of Extremely Problems with the I747M Units that is why Im posting this to try between us and fix this situation. The I747M.DLL Is not working as expected. I already have 2 units that show the Qualcomm Hub and dont have Download nor Recovery Menu Available. Yes the units are completly full bricked so for me was useless to make a backup of first 128MBs I need a backup from an Actual Working I747M from Claro PR.
BRs,
Luis Daniel
anyone who can help?
i need the one of 4.4.2

SM-T320 Hard Brick Recovery

Could someone run
Code:
dd if=/dev/block/mmcblk0 of=/sdcard/unbrick.img bs=512 count=524288
and upload it? Flashing unbrick in a 'raw' fashion will allow you to hard brick most Qualcomm devices. Unfortunately I lost my backup and I can't boot my device. This file will allow me to recover. Thanks!

I can
Will it safe to run and guide me how to run it ??? Dont know where it goes............ I also have my stock recovery file saved by flashify https://drive.google.com/file/d/0B3i0YJU831QXTHctYWphX2Y0aE0/view?usp=sharing

vincowoo said:
Will it safe to run and guide me how to run it ??? Dont know where it goes............ I also have my stock recovery file saved by flashify https://drive.google.com/file/d/0B3i0YJU831QXTHctYWphX2Y0aE0/view?usp=sharing
Click to expand...
Click to collapse
I messed up, here's the correct command
Code:
dd if=/dev/block/mmcblk0 of=/sdcard/unbrick.img bs=512 count=524288
Thank you very much!

Still not found .... run the command without error ... dont know where required file goes ... checked the root of both external and internal sd...

vincowoo said:
Still not found .... run the command without error ... dont know where required file goes ... checked the root of both external and internal sd...
Click to expand...
Click to collapse
Make sure you're running as root, from adb shell or terminal emulator. Try this one instead
Code:
dd if=/dev/block/mmcblk0 of=/storage/extSdCard/unbrick.img bs=512 count=31250
That command should have created 'unbrick.img' on your external SD card. I am extremely thankful for you doing this. My device is bricked and sitting in QHSUSB_BULK mode. You may want to save this file in case you ever need it! Thanks again, it is very much appreciated!

It is my pleasure. this forum helped me many times m trying to return something.That command completed successfully i am uploading it ?
https://docs.google.com/file/d/0B3i0YJU831QXUmViWGMyMGE1eHM/edit?usp=docslist_api

NEED 'mmcblk0.img' file

Can anybody give me 'mmcblk0.img' file for htc 10(2ps6500/2ps6500). if the phone is rooted and busybox installed it can be extracted using adb command.
To view partition tables :
adb shell su -c ls -al /dev/block/
After running this you can see this partition mmcblk0 in starting and make sure that the partition is available.
First you have to backup your file.
To backup into internal memory run this command:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/sdcard0/fulldump.img
or
To backup into external memory runthis command:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/sdcard1/fulldump.img
the file is supposed to be in GBs, so copy the file in pc, make a zip/winrar archive and upload it.
It would be a great help for me as I'm stuck with a bricked device. Thanks in advance

Capturing it now. I'm on the October 2017 unlocked firmware/ROM (RUU_PERFUME_WL_N70_SENSE80GP_VZW_MR_NA_Gen_Unlock_2.51.617.21). The command I needed to use was
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/emulated/0/fulldump.img
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=sdcard/fulldump.img
might've worked, too. I'll let you know when it's uploaded.
Edit: Filled up the 19 GB free space on internal. Let me try to external SD.
Likewise, the command for external SD on this device is:
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/ext_sd/fulldump.img
Yikes, 29GB but done. And hopefully it will compress a ton in order to upload somewhere. I'll 7-Zip it with maximum settings and see how well it compresses before I figure out where to upload it to. I don't know if I'd be able to upload something that large anywhere - I could ask AFH if it would be cool, even if it's just temporary. Guess we could always try a torrent if you're familiar with downloading torrents. I'll let you know how it compresses. It'll take at least a couple of hours to compress. Right now it's averaging 28% so it'll be less than 10 GB, I think, which is still huge.

roirraW "edor" ehT said:
Capturing it now. I'm on the October 2017 unlocked firmware/ROM (RUU_PERFUME_WL_N70_SENSE80GP_VZW_MR_NA_Gen_Unlock_2.51.617.21). The command I needed to use was
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/emulated/0/fulldump.img
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=sdcard/fulldump.img
might've worked, too. I'll let you know when it's uploaded.
Edit: Filled up the 19 GB free space on internal. Let me try to external SD.
Likewise, the command for external SD on this device is:
Code:
adb shell su -c dd if=/dev/block/mmcblk0 of=storage/ext_sd/fulldump.img
Yikes, 29GB but done. And hopefully it will compress a ton in order to upload somewhere. I'll 7-Zip it with maximum settings and see how well it compresses before I figure out where to upload it to. I don't know if I'd be able to upload something that large anywhere - I could ask AFH if it would be cool, even if it's just temporary. Guess we could always try a torrent if you're familiar with downloading torrents. I'll let you know how it compresses. It'll take at least a couple of hours to compress. Right now it's averaging 28% so it'll be less than 10 GB, I think, which is still huge.
Click to expand...
Click to collapse
You do realize this will give ALL of the info from every partition on your phone, correct? Including IMEI, serial#, and any and all data you have on it?

xunholyx said:
You do realize this will give ALL of the info from every partition on your phone, correct? Including IMEI, serial#, and any and all data you have on it?
Click to expand...
Click to collapse
No, I sure didn't. Thank you! I wondered but in my searches I didn't find that information. Well, forget that, then. [emoji16]
I had even considered, if I was prepared to RUU my 10 (the Pixel is my primary) (but I'm not), to only then capture it after.
Thank you very much!

Thanks for responding, I didn't know that will give all that partition details. I am new to xda. Thanks again.

anam_1285 said:
Thanks for responding, I didn't know that will give all that partition details. I am new to xda. Thanks again.
Click to expand...
Click to collapse
I hope you find another way to recover your phone. Is it out of the uh oh protection/warranty period?

roirraW "edor" ehT said:
I hope you find another way to recover your phone. Is it out of the uh oh protection/warranty period?
Click to expand...
Click to collapse
No it's not, hopefully they will fix it. Thanks anyways.

roirraW "edor" ehT said:
No, I sure didn't. Thank you! I wondered but in my searches I didn't find that information. Well, forget that, then. [emoji16]
I had even considered, if I was prepared to RUU my 10 (the Pixel is my primary) (but I'm not), to only then capture it after.
Thank you very much!
Click to expand...
Click to collapse
Can you provide any possible upload link for MMCBLK0.img of HTC 10, I accidentally delete the dump

Hello, is ther a way to send the mmcblk0 to pc? with adb shell su -c dd if=/dev/block/mmcblk0

Question little help

Hello fellas
i just unlocked my poco f3 and i have a habit with xiaomi devices to take backup of my EFS and persist partitions
i already done with persist partition but i cannot do for efs using this command >>
dd if=/dev/block/mmcblk0p10 of=/sdcard/modemst1.bin bs=512
dd if=/dev/block/mmcblk0p11 of=/sdcard/modemst2.bin bs=512
always end no such a directory
advice needed
thanks in advance

I haven't heard anyone talk of backing up the EFS partition. Are you sure it still exists?

Robert314 said:
I haven't heard anyone talk of backing up the EFS partition. Are you sure it still exists?
Click to expand...
Click to collapse
AS I Know EFS partition is important because it has the imei so good to back it up
i thought it can be back it up via termux but i cannot so i did via twrp and save the img in my PC in case something went wrong
be safe better than regretting

Antidote03 said:
AS I Know EFS partition is important because it has the imei so good to back it up
i thought it can be back it up via termux but i cannot so i did via twrp and save the img in my PC in case something went wrong
be safe better than regretting
Click to expand...
Click to collapse
Cheers dude, backing up EFS is something i always do too, you just reminded me on my poco!!

Antidote03 said:
Hello fellas
i just unlocked my poco f3 and i have a habit with xiaomi devices to take backup of my EFS and persist partitions
i already done with persist partition but i cannot do for efs using this command >>
dd if=/dev/block/mmcblk0p10 of=/sdcard/modemst1.bin bs=512
dd if=/dev/block/mmcblk0p11 of=/sdcard/modemst2.bin bs=512
always end no such a directory
advice needed
thanks in advance
Click to expand...
Click to collapse
Antidote03 said:
AS I Know EFS partition is important because it has the imei so good to back it up
i thought it can be back it up via termux but i cannot so i did via twrp and save the img in my PC in case something went wrong
be safe better than regretting
Click to expand...
Click to collapse
Hi,
I'm also used to backup EFS and persist partitions, via terminal emulator. I got my F3 and am waiting to unlock BL. But I don't know much about these A/B partitions...
You said you already backed up your persist partition, but may I ask how exactly ?
=> after grant su rights : dd if=/dev/block/[what-name ??]/persist of=/sdcard/persist.img
So could you please tell me what I dont know about this device ([what-name?]) ?
And about the EFS backup, what's the command prompt ? Usually, I did so :
=> dd if=/dev/block/[sdf1 ??] of=/sdcard/modemst1.bin bs=512
dd if=/dev/block/[sdf2 ??] of=/sdcard/modemst2.bin bs=512
But it seems it doesn't work... So you say you did it trough recovery, how please, only backup EFS partition ? Are the actual TWRP working to restore it, not sure someone already tried ??
Thanks very much !

néonaloj said:
Hi,
I'm also used to backup EFS and persist partitions, via terminal emulator. I got my F3 and am waiting to unlock BL. But I don't know much about these A/B partitions...
You said you already backed up your persist partition, but may I ask how exactly ?
=> after grant su rights : dd if=/dev/block/[what-name ??]/persist of=/sdcard/persist.img
So could you please tell me what I dont know about this device ([what-name?]) ?
And about the EFS backup, what's the command prompt ? Usually, I did so :
=> dd if=/dev/block/[sdf1 ??] of=/sdcard/modemst1.bin bs=512
dd if=/dev/block/[sdf2 ??] of=/sdcard/modemst2.bin bs=512
But it seems it doesn't work... So you say you did it trough recovery, how please, only backup EFS partition ? Are the actual TWRP working to restore it, not sure someone already tried ??
Thanks very much !
Click to expand...
Click to collapse
i used these
Backup E.F.S. and modem partitions for Android devices
How to backup, restore E.F.S. and modem? **This guide should work for any android device that manufactured in recent years.** E.F.S. is a crucial partition for Android devices as well as persist partition, which it stores all the important data for I.M.E.I. and I.M.S.I. numbers, W.I.F.I. and...
telegra.ph
https://www . youtube . com/watch?v=NQSAeZO7DaE&ab_channel=munchy
https://www . youtube . com/watch?v=rfAry7YpuCc&ab_channel=munchy
Do not forget remove the space in youtube links

Don't think youtube video's are banned from XDA, here's the links...
First one
And here for the second video from above (post 6)

Hi
Thanks to both of you @Antidote03 and @reg66 !!
I do know this guy's videos, wich are often great indeed.
But.. I like to know what I'm doing, so downloading his script is not my goal.. What I'd like to know is what are the exact command lines to get these backups on my side, using fastboot commands.
As I mentioned I do have what I think is some parts of the commands, but it lacks some info. To show them again :
- persist backup :
"dd if=/dev/block/[what-name ??]/persist of=/sdcard/persist.img"
but what should I replace as [what-name?] ??
- EFS backup :
"dd if=/dev/block/[sdf1 ??] of=/sdcard/modemst1.bin bs=512"
"dd if=/dev/block/[sdf2 ??] of=/sdcard/modemst2.bin bs=512"
In this case, the video shows more to be written that the part I'm wondering what I'd need for this device... (between .../block/..??../[sdf1-2 ??]/...)
Many thanks to all who could help me out !!