Hi i'd like to unyaffs a cg39 file from a sbf
ajust it a little, and pack it back to do a nandroid restore (system.img)
how do i repack my /system dump to system.img
i've read that i need to use mkyaffs2image to back it into a system.img
(and do the md5sum)
where can i get mkyaffs2image.exe for windows ?
or is there an other way to make system.img files on a windows machine ?
(or do i have to use linux for (de)packing ??)
kind regards, Collen
Hi,
As you probably know, ext4 image can be extracted from system.sin but cannot be mounted. When trying to mount it, it fails with :
[ 1476.821582] EXT4-fs (loop0): bad geometry: block count 262144 exceeds size of device (144631 blocks)
I open this thread just to share what I did around the issue and maybe have some helpful quotes about it
Here is what I did (under linux)
# First create an zero filled file. Size is system partition size (262144 blocks of 4096 each)
dd if=/dev/zero of=/home/xperia/virtualfs bs=4096 count=262144
# Attach file to loopback
sudo losetup /dev/loop0 /home/xperia/virtualfs
# Format it with same features as system partition on phone
sudo mkfs.ext4 -O has_journal,^ext_attr,^dir_index,^flex_bg,^huge_file,resize_inode,filetype,extent,sparse_super,large_file,^uninit_bg,^dir_nlink,^extra_isize -v /dev/loop0
# Write extracted system.sin.ext4 extracted image to loopback
sudo dd if=system.sin.ext4 of=/dev/loop0
# Mount filesystem
sudo mount /dev/loop0 /mnt
It can be mounted and I can have folder structure but I can't work with files. Editing default.prop gives me a non readable file.
But we can go a step ahead as we can now mount the image.
Still some issues have to be worked out.
The poit is, why we cant mount system.img on ICS but we can on GB?
maybe someone can contact with sony t oask
im extracting the .sin to .img like always but its impossible to mount.. what are you using to extract the .sin to a .ext4?
BTW, thanks for the info, i've been trying to modify system.img since ICS appeared.
EDIT: of, ext4 can be extracte with flashtool ~.~
maybe we need to read something from system.partinfo
Yakandu said:
The poit is, why we cant mount system.img on ICS but we can on GB?
maybe someone can contact with sony t oask
im extracting the .sin to .img like always but its impossible to mount.. what are you using to extract the .sin to a .ext4?
BTW, thanks for the info, i've been trying to modify system.img since ICS appeared.
EDIT: of, ext4 can be extracte with flashtool ~.~
maybe we need to read something from system.partinfo
Click to expand...
Click to collapse
Yes Flashtool can extract image from system.sin.
partinfo is partition information used by loader in flashmode to identify where to flash image on phone. (Something like start nand address of system partition)
so, any ideas why ext4 cant be mounted? maybe its encrypted or something..
Sorry for double post, i found a solution
Flash the system through a .ftf with flashtools
Flash a custom kernel with recovery (or the nozomi recovery)
Backup nandroid
We get a system.ext4.tar ··· move it to your developement folder
Create a folder (mkdir system)
Enter nautilus with root acces
Extract system files to the created folder
Modify whatever you want
Make a flashable system.img with: "./mkuserimg.sh -s /system ./system.img ext4 ./temp 1024M"
AND ITS WORKING!
Yakandu said:
Sorry for double post, i found a solution
Flash the system through a .ftf with flashtools
Flash a custom kernel with recovery (or the nozomi recovery)
Backup nandroid
We get a system.ext4.tar ··· move it to your developement folder
Create a folder (mkdir system)
Enter nautilus with root acces
Extract system files to the created folder
Modify whatever you want
Make a flashable system.img with: "./mkuserimg.sh -s /system ./system.img ext4 ./temp 1024M"
AND ITS WORKING!
Click to expand...
Click to collapse
This solution is already known
But my goal is to be able to mod a system partition without having to flash it before. And more, understand why extracted system image cannot be mounted and how to work this out
oh, ok xD
i didnt know that solution, its new for me
Yakandu said:
Sorry for double post, i found a solution
Flash the system through a .ftf with flashtools
Flash a custom kernel with recovery (or the nozomi recovery)
Backup nandroid
We get a system.ext4.tar ··· move it to your developement folder
Create a folder (mkdir system)
Enter nautilus with root acces
Extract system files to the created folder
Modify whatever you want
Make a flashable system.img with: "./mkuserimg.sh -s /system ./system.img ext4 ./temp 1024M"
AND ITS WORKING!
Click to expand...
Click to collapse
Have you already tried flashing this img on your device? I have already tried this solution twice but didn't succeed (@Spectre51 that's why I haven't replied your PM yet). system.img was succesfully created but I got boot loop when I flashed it on my device.
Hi Androxyde,
I figured it out, basically we have to dig further in sin format as new ext4 sins skips part of the file. See my thread for more details.
PS: Thanks for flashtool, it's a great tool!
LeTama
letama said:
Hi Androxyde,
I figured it out, basically we have to dig further in sin format as new ext4 sins skips part of the file. See my thread for more details.
PS: Thanks for flashtool, it's a great tool!
LeTama
Click to expand...
Click to collapse
:good:
I would like to looking for the Stock rom.zip for Tab SM-805 LTE. but can't
please share me if you have or the link for downloading
Thanks so much!
No such thing. Stock firmware comes in a tar package.
samsung-updates.com or sammobile
crownvn said:
I would like to looking for the Stock rom.zip for Tab SM-805 LTE. but can't
please share me if you have or the link for downloading
Thanks so much!
Click to expand...
Click to collapse
You need to download the whole firmware package (which is a .tar archive), extract it, and get system.img
After that, you need to use (on a either linux OS or cygwin/VM with linux) simg2img to unpack the raw partition found in system.img
Code:
simg2img system.img system.raw
Next, you need to mount that raw partition to a premade folder
Code:
mkdir system_unpacked
sudo mount -t ext4 -o loop system.raw system_unpacked
You now have your stock rom unpacked. Pack the files found in system_unpacked in a .zip, add a propper META-INF with a propper updater script and that's all
P.S. Google is your friend in all this process!
P.P.S. if your tablet is already rooted, you can use flashfire on it to directly flash the system.img (as @ashyx mentioned in his great rooting guide)
All in all, good luck! Cheers!:good:
Has anyone been able to repack system.img using these tools? I've tried a couple variations of of parameters for mkuserimg, but everytime it gets stuck on the boot animation.
simg2img ./system.img system.raw
sudo mount -t ext4 -o loop system.raw ./mount/system/
sudo mkuserimg.sh -s mount/system/ system_new.img ext4 /system 3221028864
I've also tried
sudo mkuserimg.sh -s mount/system/ system_new.img ext4 /system 3195826176
Neither one works. The first one gets the file size of the .raw files to match, but the number of blocks (per tune2fs) differ. The second one gets the number of blocks to match, but not the .raw file sizes.
The base system.img I have flashes without any problems.
Appreciate any help!
Did you disabled the encryption in the boot.img ? It might be getting stuck since the signatures don't match. Have a look at the boot.img used to root. The fstab entries are relaxed. I think there is another change from stock.
gee one said:
Did you disabled the encryption in the boot.img ? It might be getting stuck since the signatures don't match. Have a look at the boot.img used to root. The fstab entries are relaxed. I think there is another change from stock.
Click to expand...
Click to collapse
Definitely using a boot.img with encryption disabled. Using this one: http://forum.xda-developers.com/apps/supersu/wip-android-6-0-marshmellow-t3219344
I've tried running both stock system.img through the repack process and a AOSP built system.img and both images stop working once run through mkuserimg
Maybe I'll give the ElementalX kernel a try.
After extracting the ramdisk from the stock boot image of OSS5.0 / Android O 8.0 for Oneplus3, I noticed that fstab.qcom file is no longer there in the ramdisk. Until OSS4.5.1 / Android N 7.1 this file was present and could be edited to set the flag for data partition to encryptable and to also remove the verity flag ...both of which I found to be very useful.
Appreciate if someone can please help me understand what has changed in the Android O 8.0 and what would be the method to achieve the above?
Looking at https://forum.xda-developers.com/oneplus-3t/how-to/disable-dm-verity-force-encryption-op3t-t3688748 and https://forum.xda-developers.com/attachment.php?attachmentid=4302571&d=1507993390, it appears that the fstab.qcom file has moved to /system/vendor/etc/fstab.qcom in Oreo in keeping with Android O / 8.0 specifications. Changing that file means modifying the system partition, which I don't mind as I like to modify the hosts file as the barest minimum change even in my daily use device. But still wondering if the same can be achieved by Magisk and how. Appreciate if someone can help me understand this.
Today's learning:
1. Android O kernel specifications include early mounting of some partitions and Oneplus 3 specifies the system partition in its device tree blobs (dtb).
2. These dtb are part of (...appended to) the real kernel image and not on a separate partition / blob.
3. There are 13 dtb appended to Oneplus 3 kernel and each of them has an entry relevant to fstab which mounts system with the verify flag.
4. Again, in keeping with Android O specifications, fstab.qcom (...now located in the /vendor/etc/ directory) does not include a line for the system partition (...commented out) as mounting the system partition is already taken care of through the dtb in the kernel.
5. That means system modifications cannot be done until the dtb are cleaned of verify flag .... or perhaps the whole of the code mounting the system partition in dtb is deleted and then fstab.qcom is restored in the ramdisk.
Haven't yet tried this and it will be helpful if someone more knowledgeable can confirm that these are the steps to be done to modify the system partition.
@rk2612 great findings and write up!
Just saw your post at magisk beta thread. I'm facing same problem on xperia device with Oreo, and I think we need to change the flag as you stated there.
I've already tried flashing magisk, but dm-verity is still being triggered and phone falls in a bootloop after it reboots.
I'd like to try this method out on my xperia, but I don't know how to convert dtb into dts, and vice versa. Any help on this would be great! Thanks in advance!!
serajr said:
@rk2612...
I've already tried flashing magisk, but dm-verity is still being triggered and phone falls in a bootloop after it reboots.
I'd like to try this method out on my xperia, but I don't know how to convert dtb into dts, and vice versa. ...
Click to expand...
Click to collapse
Have you tried patching with Magisk Beta v1456? That seems to take care of the verity flag in the dtb of OnePlus 3.
On Ubuntu, you can install dtc (device tree compiler ...Refer http://manpages.ubuntu.com/manpages/xenial/man1/dtc.1.html ) to handle conversion from dtb to dts or vice versa.
rk2612 said:
Have you tried patching with Magisk Beta v1456? That seems to take care of the verity flag in the dtb of OnePlus 3.
On Ubuntu, you can install dtc (device tree compiler ...Refer http://manpages.ubuntu.com/manpages/xenial/man1/dtc.1.html ) to handle conversion from dtb to dts or vice versa.
Click to expand...
Click to collapse
Thank you bro!
Yes, I had, latest beta v1456!
Gonna try it out and report back here later!!
serajr said:
...
I'd like to try this method out on my xperia, ....
Click to expand...
Click to collapse
serajr said:
Thank you bro!
Yes, I had, latest beta v1456!
Gonna try it out and report back here later!!
Click to expand...
Click to collapse
According to https://github.com/topjohnwu/Magisk/blob/master/scripts/boot_patch.sh (...line 93 onwards) Sony devices may not be handled well by Magisk.
rk2612 said:
According to https://github.com/topjohnwu/Magisk/blob/master/scripts/boot_patch.sh (...line 93 onwards) Sony devices may not be handled well by Magisk.
Click to expand...
Click to collapse
Bro, this is an known issue for all xperia users. Always before we flash magisk (os SuperSU), we do need to convert xperia stock kernel (elf format) to boot.img (aosp format), and fastboot it!
And for the records, this is exactly what I've found with dtc:
Code:
firmware {
android {
compatible = "android,firmware";
fstab {
compatible = "android,fstab";
vendor {
compatible = "android,vendor";
dev = "/dev/block/platform/soc/7464900.sdhci/by-name/vendor";
type = "ext4";
mnt_flags = "ro,barrier=1,discard";
fsmgr_flags = "wait";
status = "disabled";
};
system {
compatible = "android,system";
dev = "/dev/block/platform/soc/7464900.sdhci/by-name/system";
type = "ext4";
mnt_flags = "ro,barrier=1,discard";
fsmgr_flags = "wait[B][COLOR="Red"],verify[/COLOR][/B]";
status = "ok";
};
};
};
};
Removed ,verify and conveted back to dtb. Gonna test it out (report you back later)!
Thank you!
i have a one plus 5T and i dont see an DTB files in the boot.img
can someone post a walk through on how to do this manually without magisk or supersu?
i know i can modify the fstab in system/vendor/etc
but what are the dtb files exactly? and where are they located / how are they extracted?
virtyx said:
i have a one plus 5T and i dont see an DTB files in the boot.img
can someone post a walk through on how to do this manually without magisk or supersu?
i know i can modify the fstab in system/vendor/etc
but what are the dtb files exactly? and where are they located / how are they extracted?
Click to expand...
Click to collapse
DTB are Device Tree Blobs / Binary and not files. These are appended to the kernel in the boot.img.
On Ubuntu, you can install dtc (device tree compiler ...Refer http://manpages.ubuntu.com/manpages/...an1/dtc.1.html ) to handle conversion from dtb to dts or vice versa.
You can also hex edit the boot.img and delete the text ",verify" at each instance it is found. Or use Linux command line to do that if you're familiar with that.
Sorry, don't have the spare time right now to write a detailed walk through. Maybe this weekend.
rk2612 said:
DTB are Device Tree Blobs / Binary and not files. These are appended to the kernel in the boot.img.
On Ubuntu, you can install dtc (device tree compiler ...Refer http://manpages.ubuntu.com/manpages/...an1/dtc.1.html ) to handle conversion from dtb to dts or vice versa.
You can also hex edit the boot.img and delete the text ",verify" at each instance it is found. Or use Linux command line to do that if you're familiar with that.
Sorry, don't have the spare time right now to write a detailed walk through. Maybe this weekend.
Click to expand...
Click to collapse
thank you
is it possible to extracat the DTB files on a windows machine?
i know after OS install the fstab is located at /system/etc/vendor which we can edit before first boot
but id prefer to edit the DTB files in the boot, and add mounting flags for each partition.
virtyx said:
thank you
is it possible to extracat the DTB files on a windows machine?
i know after OS install the fstab is located at /system/etc/vendor which we can edit before first boot
but id prefer to edit the DTB files in the boot, and add mounting flags for each partition.
Click to expand...
Click to collapse
I didn't look around for a windows tool to extract DTBs.
In Oreo, fstab file contains the mount points for all other partitions except /system and you can edit the fstab file as in previous android versions. The only partition which is mounted early through the DTBs is /system and you will see that the /system mount entry in fstab is commented out as that is not needed.
To mount /system with verity disabled, you will need to remove the flag "verify" from the DTBs. I'm attaching a text version of one of the 13 DTBs contained in OnePlus 3's boot image as an example. You will notice the following code
Code:
fsmgr_flags = "wait,verify"
...and you need to remove ",verify" to make it
Code:
fsmgr_flags = "wait"
To remove ",verify" from the DTBs, you can either:
1. Hex edit the boot image but this will leave the verity key in the ramdisk (...may work but I haven't tried).
2. (a) Unpack the boot image; (b) hex edit the kernel (to which dtbs are appended) and remove ",verify"; (c) extract ramdisk and remove verity.key; (d) repack ramdisk; and (e) repack the boot image: should work
3. (a) Unpack the boot image, (b) extract the dtb appended to kernel / zImage; (c) convert the dtb to dts (text format); (d) text edit the dts to remove ",verify"; (e) then reconvert dts to dtb; (f) append all the modified dtbs to the kernel; and finally (g) repack the boot image (...also remove the verity.key from the ramdisk before repacking the boot image): this would be the cleanest approach but more cumbersome.
Tools needed on Ubuntu machine with Python installed:
1. Unpack and repack boot image: use unpackbootimg and mkbootimg scripts (Python) from lineageos code: https://github.com/LineageOS/android_system_core/tree/cm-14.1/mkbootimg
2. Extract kernel and dtbs using python script: https://github.com/PabloCastellano/extract-dtb
3. Convert dtb to dts and back: use Ubuntu package dtc: http://manpages.ubuntu.com/manpages/xenial/man1/dtc.1.html
rk2612 said:
I didn't look around for a windows tool to extract DTBs.
In Oreo, fstab file contains the mount points for all other partitions except /system and you can edit the fstab file as in previous android versions. The only partition which is mounted early through the DTBs is /system and you will see that the /system mount entry in fstab is commented out as that is not needed.
To mount /system with verity disabled, you will need to remove the flag "verify" from the DTBs. I'm attaching a text version of one of the 13 DTBs contained in OnePlus 3's boot image as an example. You will notice the following code
Code:
fsmgr_flags = "wait,verify"
...and you need to remove ",verify" to make it
Code:
fsmgr_flags = "wait"
To remove ",verify" from the DTBs, you can either:
1. Hex edit the boot image but this will leave the verity key in the ramdisk (...may work but I haven't tried).
2. (a) Unpack the boot image; (b) hex edit the kernel (to which dtbs are appended) and remove ",verify"; (c) extract ramdisk and remove verity.key; (d) repack ramdisk; and (e) repack the boot image: should work
3. (a) Unpack the boot image, (b) extract the dtb appended to kernel / zImage; (c) convert the dtb to dts (text format); (d) text edit the dts to remove ",verify"; (e) then reconvert dts to dtb; (f) append all the modified dtbs to the kernel; and finally (g) repack the boot image (...also remove the verity.key from the ramdisk before repacking the boot image): this would be the cleanest approach but more cumbersome.
Tools needed on Ubuntu machine with Python installed:
1. Unpack and repack boot image: use unpackbootimg and mkbootimg scripts (Python) from lineageos code: https://github.com/LineageOS/android_system_core/tree/cm-14.1/mkbootimg
2. Extract kernel and dtbs using python script: https://github.com/PabloCastellano/extract-dtb
3. Convert dtb to dts and back: use Ubuntu package dtc: http://manpages.ubuntu.com/manpages/xenial/man1/dtc.1.html
Click to expand...
Click to collapse
ah i see
i guess i should really dual boot this machine haha
i found the mounting options in hex editor for the boot.img (/system and /vendor, i think 13 instances of both)
also the verity.key can be delete when unpacking the boot.img and repacking it with no verity.key.
thank you, i think im able to modify it on a windows machine, ill try it out as soon as a stable oreo comes out for the 1+5T
I already have the dtb edited. how can I add them back to the zImage or the boot.img?
Thank you very much
kenet said:
I already have the dtb edited. how can I add them back to the zImage or the boot.img?
Thank you very much
Click to expand...
Click to collapse
Actually the appending should be done like
Code:
cat zImage [I][U]<DTB_FILE_NAME>[/U][/I].dtb > zImage-dtb
So you can get a zImage with dtb