Do firmware updates affect apps/data?

Hi
I have the option to upgrade to froyo with kies but i didnt because im not sure about a couple of things:
1. I have rooted my sgs, is it going to be a problem? also I used the leg fix .
Am I supposed to undo the root and leg fix before upgrading?
2. After I rooted the phone i pushed hebrew fonts into it. are they going to disapear?
3. If the root will disapear is there another root app for sgs with froyo?
4. Can I backup tha eclaire on my device so if something will go wrong I could just restore it ?

thanks everyone !!!

You do need a factory reset after froyo updated..... if you want your galaxy s to work correctly.  And yes....reinstalling apps would be a pain.  Backing up under eclair is perfectly fine, and that's what you should do....
and, some but not all apps are compatible with froyo.

Thanks for your answers, I really appreciate it   

Apologies if I am being a bit slow understanding this, but I am still not quite clear...


I have known factory resets that remove everything except firmware, and others that leave data (& sometimes apps) in memory, due to different types of ROM/RAM in different embedded devices.

I also contacted Samsung about the GPS issue and was advised to reset the phone, but they suggested the apps/data would be unaffected (not that I trust technical support to actually know what they are talking about).

Hence I still don't know whether the froyo update (and necessary factory reset) will remove all my apps.


Would be, or WILL be?


Does the backup process backup apps as well as data?  How do I perform this backup?


Any way of knowing in advance what is likely to stop working?


I have heard this as well, perhaps it depends if you are installing the official update or a leaked/cooked ROM?

I just want to know about the official froyo at this stage.  Is there anyone who has done it who can describe the entire process and confirm yes or no?


What about apps not installed via Market?  ie .apk's transferred from PC, or via the browser?

I have been using my SGS for development work as well, so I have apps pushed through 'adb'. What happens to these?

Thanks in advance...

About just mirroring the device on your PC, I tried a verison of that by installing apps on SDCards and swapping the SD cards. More painful than just re-installing but that was WINMO and maybe it's better on Android.

XDA does have an SGS specific forum.