Firmware update internals

[m2tk]

Hi.
Does anybody know something more how is going firmware update process?
The firmware file is something about 750MB.
Where is it downloaded, to RAM memory?
What process is responsible for making the update?
Can it be interrupted during the update?
Are the files decrypted before update?
How do the TV knows if it's correct/newer firmware file?

Do you know the place where I can get more knowlegde on this?
Thank you.