Database Develop

[Q] What happens to /system when a rom is installed?

I'm sure this question has been answered before, but I can't find it anywhere, so here goes:
I always thought that whenever a ROM is installed it completly wipes and overwrites the /system partition. But perhaps I figure wrong, maybe the files/folders within /system are overwritten and any other pre-existing files are left behind.
Which is it?
I ask this because I notice that the size of /sytem in an update.zip varies from one ROM to another, this suggests to me that perhaps files can be left behind when a ROM is installed. Also I'm curious why it's sometimes possible to upgrade a rom without a wipe and sometimes it isn't.

It depends on how the ROM is set up to install...
Basically, a flashable zip is just a bunch of files and a script that installs the package. If the script also has instructions to erase files or directories, then it will...
Sent from my Nexus One using XDA App

it depends on what you are doing. if i flash a full ROM to my phone, it will just upgrade everything as if it were a real OTA from google, meaning it keeps every thing in tact. if i wipe the phone first, of course it re-writes everything. so it's a tough question to answer.

Thanks danger-rat, perfect explanation.
It's quite interesting that we rely on the ROM-dev to wipe whatever is necessary (as a manual wipe from Recovery-mode does not wipe /system). So I guess it's possible to install a new ROM and be left with bits of the old one still in /system if the ROM-dev didn't specifiy a format of /system.
danger-rat said:
It depends on how the ROM is set up to install...
Basically, a flashable zip is just a bunch of files and a script that installs the package. If the script also has instructions to erase files or directories, then it will...
Sent from my Nexus One using XDA App
Click to expand...
Click to collapse

[APP] MakeUpdateZip-20110303 **Multi-file capable**

This is not only my first Android app, but this is also my first dive in Java. Please be gentle as I expect there are several uncaught / improperly handled exceptions.
This app will backup selected files to a zip file that can be restored via cwm. For now, that is all it does. It can be handy for the oc/uv crowd since it will allow you to keep a backup of a good S_volt_scheduler init file to flash in case your new setting are too aggressive. It does not currently restore permissions, nor does it assume root permissions.
todo:
Obtain root to copy any file
Integrate a file selector so read permissions will not be an issue.
Detect/Restore permissions
Possible feature additions:
Create a restore.zip from current files based on an update.zip you want to apply. Could save you from boot loops when messing with system files.
Create a restore.zip given a file, a target directory, and permissions.
I will probably add this to the market once I get through the todos and initial bugs.
Changelog:
20110303
Multi-file capable. OIFileManager does not yet support multi-select, so each file must be selected seperately
Exception caught for mission OIFileManager
_delete.zip file seems to work correctly in recovery
Since I am not yet using root and OIFileManager will not assume root, there are some directories that cannot be viewed, /data/app for example. There are also some files that can be selected but cannot be copied due to their permissions.
Requires OIFileManager

Nice, will be useful

This looks like it could be a useful/powerful app. It could definitely benefit from some features (more than one file/location would be great) but I can see myself using this.
Thanks!

gibson3659 said:
This is not only my first Android app, but this is also my first dive in Java. Please be gentle as I expect there are several uncaught / improperly handled exceptions.
This app will backup 1 file to a zip file that can be restored via cwm. For now, that is all it does. It can be handy for the oc/uv crowd since it will allow you to keep a backup of a good S_volt_scheduler init file to flash in case your new setting are too aggressive. It does not currently restore permissions, so the uses are currently limited.
todo:
Figure out why the _delete.zip does not delete the target file when run via cwm.
Detect/Restore permissions
Possible feature additions:
Enable backup/restore of multiple files
Create a restore.zip from current files based on an update.zip you want to apply. Could save you from boot loops when messing with system files.
Create a restore.zip given a file, a target directory, and permissions.
I will probably add this to the market once I get through the todos and initial bugs.
Requires oifilemanager.
Click to expand...
Click to collapse
Can u load the java app here? I can try to look into that and see if I can improve on the exception handling part.

fantastic idea
good job

Thanks for taking a look. Have anyone of you actually tried it?

It fc. On me... :'(
Sent from my SGH-I897 using XDA App

Do you have oifilemanager?
Sent from my SGH-I897 using XDA App

gibson3659 said:
Do you have oifilemanager?
Sent from my SGH-I897 using XDA App
Click to expand...
Click to collapse
Forgot that
Sent from my SGH-I897 using XDA App

Works like a charm! thank you so much! Perfect cause I love the stock music player and not all rims have it so this is great for installing it!
Sent from my SGH-I897 using XDA App

I am working on multiple file support, so look for a new version in a day or two.
Sent from my SGH-I897 using XDA App

just installed it, however it force closes as soon as I try to choose a source or destination file (happens as soon as I press the buttons.
Herp derp Captivate XDA app.

Make sure you install OIFilemanager from the market. I need to catch this exception and provide a link to OIFileManager.

Great App
Want to say thank you for making this. I've had all sorts of trouble getting apps from different roms to install to the system folder on my current rom. Now I can mix and match different apps easily without much pain. Thanks!

bpurkapi said:
Want to say thank you for making this. I've had all sorts of trouble getting apps from different roms to install to the system folder on my current rom. Now I can mix and match different apps easily without much pain. Thanks!
Click to expand...
Click to collapse
You are welcome. I actually have another app in mind to fully address that need, but I want to get further along with this one first. Since I am working on these on stolen time (I don't have any free time), it will take a while.
Since the apps seem to restore without permission issues, I may put that on the back burner. After I complete multi-file support, which of the future features from the op would you like to see first.

gibson3659 said:
Make sure you install OIFilemanager from the market. I need to catch this exception and provide a link to OIFileManager.
Click to expand...
Click to collapse
And I need to learn how to read through a thread for answers to my problems before I post about them.

New Version
Changelog:
20110303
Multi-file capable. OIFileManager does not yet support multi-select, so each file must be selected seperately
Exception caught for mission OIFileManager
_delete.zip file seems to work correctly in recovery
Since I am not yet using root and OIFileManager will not assume root, there are some directories that cannot be viewed, /data/app for example. There are also some files that can be selected but cannot be copied due to their permissions.

Can I get a gauge on the interest level for this app? Should I move this to the I9000 forum?

I think it's really useful when working whit OC/UV.

gibson3659 said:
Can I get a gauge on the interest level for this app? Should I move this to the I9000 forum?
Click to expand...
Click to collapse
I think you should get with rom devs, this should become an integrated feature for all rom upgrades, regardless of phone
at least get with the AIO dev, if you arent already

[Question]:zImage and modem binary swaps

I like to tweak my ROMs before a flash. i.e. make changes to /system apps; framwork tweaks... etc.
However, whenever I try to replace a kernel zImage or modem binary(using 7z, so as not open archive), I get stuck at a bootloop.
I can replace .apks and .pngs no problem using this method.
Can zImage and .bin be replaced as well? Does redbend also need to be copied? Since .bin and zImage reside in same folder in ROM... which redbend to use if needed?
Thank you?

Whenever I use a new kernel in Loki, or test one personally, I use the version of redbend that the dev included with their kernel initially. Modem does not seem to matter. Are you using a kernel that is meant for the version of Android that matches your rom? If you want to, specifically, what are you using?

This is interesting to me as well, as I did not know you could flash a zip that had been added to, so can you briefly explain how this is done? I would much rather inject my apps than do the titanium backup dance.
I also noticed that SGS Kernel flasher flashes the zImage by simply copying it, and rebooting.
If you are about to tell me I can manipulate my FS to add anything i want, in an update.zip, then sir, I love you.
BTW, if its a simple explanation, whats the redbend file do?

Br1cK'd said:
Whenever I use a new kernel in Loki, or test one personally, I use the version of redbend that the dev included with their kernel initially. Modem does not seem to matter. Are you using a kernel that is meant for the version of Android that matches your rom? If you want to, specifically, what are you using?
Click to expand...
Click to collapse
Exactly what Br1cK'd said. Use the redband that's with the kernel. If pulling the kernel from a rom and a modem from a different one same deal. Also be careful which kernels you use ie: right kernel for phone and version of Android.

d33dvb said:
This is interesting to me as well, as I did not know you could flash a zip that had been added to, so can you briefly explain how this is done? I would much rather inject my apps than do the titanium backup dance.
I also noticed that SGS Kernel flasher flashes the zImage by simply copying it, and rebooting.
If you are about to tell me I can manipulate my FS to add anything i want, in an update.zip, then sir, I love you.
BTW, if its a simple explanation, whats the redbend file do?
Click to expand...
Click to collapse
No sir it is not quite that simple. Proper settings have to be in the update script for everything to install properly. Replacing one file for another of the same name usually works and some files can be added but system apps and additional folders need to be in the update script.

Br1cK'd said:
Whenever I use a new kernel in Loki, or test one personally, I use the version of redbend that the dev included with their kernel initially. Modem does not seem to matter. Are you using a kernel that is meant for the version of Android that matches your rom? If you want to, specifically, what are you using?
Click to expand...
Click to collapse
Br!ck'd, fan of your work and EDT as a whole... great dev team! It happens on any kernel/ROM combo I have tried, which is interesting. Update.zips just carry signed certs and simple copy bash scripts, essentially pushing new files to correct directories, correct? I definitely check for kernel compatability before, I am noobish, not noobtacular
d33dvb said:
This is interesting to me as well, as I did not know you could flash a zip that had been added to, so can you briefly explain how this is done? I would much rather inject my apps than do the titanium backup dance.
I also noticed that SGS Kernel flasher flashes the zImage by simply copying it, and rebooting.
If you are about to tell me I can manipulate my FS to add anything i want, in an update.zip, then sir, I love you.
BTW, if its a simple explanation, whats the redbend file do?
Click to expand...
Click to collapse
1. I believe redbend is samsung tool for flashing volatile memory (NAND).
2. You can use 7zip to explore archives/apks without extracting them and breaking signings. Thus you can simple copy paste .apks/.pngs to appropriate directories without extracting
Most update zips are the actually apk and simple scripts in a flashable container. Roman form EDT has an excellent tool for creating flashable zips if interested... but yes you can manipulate file system of phone and archives. I use adb from recovery. Or android commander is a useful tool as well
EDIT: Explodingboy gives better explanation above

I use untermench's modified redbend. It's the same thing except it removes that ugly blue splash screen every time it is run. That said, I've simply copied over OS and CW into the trigger zips to override the stock kernel. And I never received any reports if it not working from anyone (and I've had releases with both).
Point being, in my experience it doesn't really matter (so long as everything matches). I've done the same for previous modems.
And as you said, all it's doing is copying them to the proper partitions.
Sent from my SGH-T959 using Tapatalk

birgertime said:
I use untermench's modified redbend. It's the same thing except it removes that ugly blue splash screen every time it is run. That said, I've simply copied over OS and CW into the trigger zips to override the stock kernel. And I never received any reports if it not working from anyone (and I've had releases with both).
Point being, in my experience it doesn't really matter (so long as everything matches). I've done the same for previous modems.
And as you said, all it's doing is copying them to the proper partitions.
Sent from my SGH-T959 using Tapatalk
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Click to collapse
Very cool... thanks.
Also, you are going to think I am crazy... but that ugly blue splash screen can tell me if it is a bad flash or not. When it happens on the top of screen= good flash, on bottom = gonna need to flash again, cause behavior goes wonky. Maybe just bizarre coincidence???

Poser said:
Br!ck'd, fan of your work and EDT as a whole... great dev team! It happens on any kernel/ROM combo I have tried, which is interesting. Update.zips just carry signed certs and simple copy bash scripts, essentially pushing new files to correct directories, correct? I definitely check for kernel compatability before, I am noobish, not noobtacular
Click to expand...
Click to collapse
I've seen you around, you're not noobtacular, but hell I'm still way noobish about a lot of things. Dig the avatar btw. I don't know if I can give an intelligent enough answer to your question, would probably have nobody running Loki by tomorrow, lol. Have you grabbed any logs, or tried to, while its looping?

I have no issues doing this with winrar.
Sent from my Amazing Captivate using the XDA Premium App Infused with Tiger Blood

Br1cK'd said:
I've seen you around, you're not noobtacular, but hell I'm still way noobish about a lot of things. Dig the avatar btw. I don't know if I can give an intelligent enough answer to your question, would probably have nobody running Loki by tomorrow, lol. Have you grabbed any logs, or tried to, while its looping?
Click to expand...
Click to collapse
<Palm to forehead> Probably should logcat... duh.
Just flashed with with custom kernel/modem combo... seems to be booting fine, will report any anomalies.
Only thing I did different was copy zImage and redbend from Kernel.zip
Thanks peoples!

[Q]Difference between ROM & Kernel?

Would appreciate it if someone can explain to me the difference between a kernel and a Rom.
And also, what does it mean by "pushing to /system/app"?
Thanks in advance.

http://lmgtfy.com/?q=kernel+rom

Can someone guide me on how to push an app to system/app please?
I know it has something to do with ADB but I do not know the exact steps. Thanks.

At first you need root access. Then you need an app like 'Root Explorer' and with this app you can push files into /system - folder.
Sent from my GT-I9000 using XDA Premium App

Imagine a rom as a car. The kernel would be the engine.
Sent from my DynaTAC 8000X

sendokan said:
http://lmgtfy.com/?q=kernel+rom
Click to expand...
Click to collapse
How about a better answer?
A kernel is a piece of software (kind of like a program/executable) that interfaces directly with your hardware and provides a standardized interface for higher level software to use that hardware.
ROM means Read Only Memory. In this case, ROM is not the proper term but it is in common usage despite the fact that you can write it/overwrite it. Regardless of the details, for your purposes, a ROM is the higher level software that provides interfaces between the kernel and you. E.G. the libraries, windows manager, etc.
I am unsure in this context, but I think the ROM contains the CSC stuff too. The CSC contains stuff specific to a particular locale or vendor such as programs like Layar or codes for APNs.
I followed the above Let Me Google That For You link and this thread was the first one that popped up. I quickly browsed a few other threads but getting any real meaning was going to be quite tedious.
Good luck and have fun.

strikethree said:
How about a better answer?
A kernel is a piece of software (kind of like a program/executable) that interfaces directly with your hardware and provides a standardized interface for higher level software to use that hardware.
ROM means Read Only Memory. In this case, ROM is not the proper term but it is in common usage despite the fact that you can write it/overwrite it. Regardless of the details, for your purposes, a ROM is the higher level software that provides interfaces between the kernel and you. E.G. the libraries, windows manager, etc.
I am unsure in this context, but I think the ROM contains the CSC stuff too. The CSC contains stuff specific to a particular locale or vendor such as programs like Layar or codes for APNs.
I followed the above Let Me Google That For You link and this thread was the first one that popped up. I quickly browsed a few other threads but getting any real meaning was going to be quite tedious.
Good luck and have fun.
Click to expand...
Click to collapse
first one is a thread from a year ago with exactly the same title

The kernel manages system resources and functions like a bridge between applications and hardware. One could compare it in many ways, but this is generally what it does.

Thanks all for the explanation. Will search around to understand the differences.

Lunchbox115 said:
At first you need root access. Then you need an app like 'Root Explorer' and with this app you can push files into /system - folder.
Sent from my GT-I9000 using XDA Premium App
Click to expand...
Click to collapse
May I know how exactly do I push the apk to /system/app? I have Root Explorer installed already.
Do I move the apk to /system/app then install it from there? Or am I supposed to install the normal way, then shift the apk from /data/app (where apps are usually installed to right?) to /system/app?

Which *.apk do you want to install?
Normally you just have to click on the *.apk (with any file manager) and you can install it.

At first, you need root.
After that, you have a few ways to do this:
Way 1: Use any File Explorer, which can get SU permission and access the system folder.
Then copy & paste
Way 2: You could connect your device to your computer with a USB cable (Debug-Mode on!).
Then you couls google a ADB tool.
Or you open the command line and type this into your cmd:
cd [drive]:\[folder where adb is located]\
adb root
After that you could find out where you are with the "ls" command.
Sent from my GT-I9000 using XDA Premium App

Lunchbox115 said:
Which *.apk do you want to install?
Normally you just have to click on the *.apk (with any file manager) and you can install it.
Click to expand...
Click to collapse
I am actually trying to do this --> http://forum.xda-developers.com/showthread.php?t=1123830
Installing
You can install the EDT Tweaks app or you can push it to /system/app
You must push SystemUI.apk to /system/app
I don't want to make a flashable quite yet because I want more experienced users to test this out, etc
Click to expand...
Click to collapse
So am I supposed to push first then install or the other way round?
I tried installing the normal way, then shifted the apk from /data/app to /system/app but received an error when I tried to open the app.

Anybody please?

[Q] Creating a back door

Some of the recent posts have suggested that we may soon see a patch for the root exploit we currently have.
Being that we have root now is there some place we could hide SU where we could access it later should root be closed on us, allowing re-rooting of the device? It would have to be some place that does not get overwritten when an update is pushed...and I am not sure if that even exists on Android.

Not easily, since system is one of two partitions that doesn't have nosuid or noexec set.
Sent from my DROID3 using xda premium

Dunno about that, but I've been told there are a couple root methods being saved for later....

So I guess I am correct in assuming that the entire /system gets overwritten during an update?
I just played a bit with /root but cannot get anything to run with the current permissions of the mount.
For my understanding am I correct in the belief that all system directories get overwritten "/sys/ /system/"?

slow88lx said:
Dunno about that, but I've been told there are a couple root methods being saved for later....
Click to expand...
Click to collapse
Thank god for this!
Sent from my DROID3 using XDA App

calash said:
So I guess I am correct in assuming that the entire /system gets overwritten during an update?
I just played a bit with /root but cannot get anything to run with the current permissions of the mount.
For my understanding am I correct in the belief that all system directories get overwritten "/sys/ /system/"?
Click to expand...
Click to collapse
It doesn't get overwritten, but the update does reset all permissions. Thus, the su executable will still be there after the update, but will be chmodded 0755.

Just brainstorming so feel free to tell me I'm wrong
What about replacing a suid binary. Ping is the one I am thinking of right now. Would the update replace that file?
Sent from my DROID3 using Tapatalk

calash said:
Just brainstorming so feel free to tell me I'm wrong
What about replacing a suid binary. Ping is the one I am thinking of right now. Would the update replace that file?
Click to expand...
Click to collapse
Looking at the permissions set in the update's script, it doesn't look feasible. If I'm reading them right, PING's permissions only allow it access to the NET_RAW group, which doesn't give us anything useful. Everything else is just as unhelpful.
Anyone know if it would be possible to fastboot flash an older recovery to a device with a newer bootloader, then temproot that and use it to permroot the device?

Xenoproctologist said:
Looking at the permissions set in the update's script, it doesn't look feasible. If I'm reading them right, PING's permissions only allow it access to the NET_RAW group, which doesn't give us anything useful. Everything else is just as unhelpful.
Anyone know if it would be possible to fastboot flash an older recovery to a device with a newer bootloader, then temproot that and use it to permroot the device?
Click to expand...
Click to collapse
Sorry to go off topic, but am I the only one who's wondering how ironic it is that a user named "xenoproctologist" is responding to a thread titled "Creating a Back Door"?
Freud would have a goddamn field day with this!

rynosaur said:
Sorry to go off topic, but am I the only one who's wondering how ironic it is that a user named "xenoproctologist" is responding to a thread titled "Creating a Back Door"?
Freud would have a goddamn field day with this!
Click to expand...
Click to collapse
No, no... I only use pre-existing back doors. ^_^

I would rather have bugs than no root. I sat on my droid3 until root was available rather than activating it.
Would it be possible in that case to run FOTAkill on a rooted d3? If so, would it help?
I noticed a couple of OTA/update related apks while noodling with Titanium.... could those be frozen to prevent updates?

hiddenhandgun said:
I would rather have bugs than no root. I sat on my droid3 until root was available rather than activating it.
Would it be possible in that case to run FOTAkill on a rooted d3? If so, would it help?
I noticed a couple of OTA/update related apks while noodling with Titanium.... could those be frozen to prevent updates?
Click to expand...
Click to collapse
There are only one or two lines in build.prop that need to be changed to prevent receiving OTAs or update notifications. Search on the DroidX forums and you'll find these values.

Editing the build.prop is not the best way to prevent OTA updates.
It will cause issues with Market and other functions that read those strings for various reasons.
Disabling by freezing or renaming BlurUpdater_VZW.apk and FOTA.apk is safer and will not affect anything else adversely.

cellzealot said:
Editing the build.prop is not the best way to prevent OTA updates.
It will cause issues with Market and other functions that read those strings for various reasons.
Disabling by freezing or renaming BlurUpdater_VZW.apk and FOTA.apk is safer and will not affect anything else adversely.
Click to expand...
Click to collapse
Thanks. I'll give that a go.

There is always something being worked on to retain/get root again after a patch. There is also a good reason it doesn't get talked about in any kind of detail.