Originally Posted by obsessed2
I think the download link for the OTA update was likely embedded within the EE or PE Update App.
I'm really interested where this OTA update was stored when it was downloaded by the EE or PE. By placing the update.zip into this location it may be possible to update the EE or PE using the Update App.
There is one big problem in what you are proposing, having people messing about with files in system directories. While this is OK for you and I and a few more knowledgeable people, it is not OK for the vast amount of users - just look at the number of problems we have seen from people not being able to rename a file correctly.
In theory it should be possible to modify the update app to accept a different location for the update file, one that can be selected via a dialogue box and be either an OTA server or a local PC. If that was done the end user would not have to get into the workings of the system and would therefore have less likelihood of making mistakes, I am assuming there is some sort of checking for the correct device update file in the update app.
On inspection it appears that update.sh in the root of update.zip looks at build.prop in tools.zip to check if it is the correct update.zip - edge or edgejr so at least some thought went into making sure the correct update was applied to the device.