[Galaxy S I9000 Android Development] Richthofen:
I had a look on this issue today, when I finally found a phone with the "3-button combos" disabled.

So far it seems that Samsung either intentionally disabled the "3-button combos" in the newer firmware version or it is simply a bug in the bootloader(s).

Tons of european I9000´s have passed thru my hands before and they all have had the "3-button combos" enabled. What they also had in common was the factory firmware version. With "factory firmware" version I mean the so called low level version which will contain everything, including bootloaders.

The firmware releases found in web (like my releases) are usually so called "mid" or "high" packages, which means they do not contain low level stuff like bootloaders. They are used for updating the other modules of the rom, while leaving the low level stuff intact.

All the phones which had the "3-button combos" enabled were programmed with I9000XXJF3 (sales variant does not matter - CSC) "low level" firmware package in the factory (this value is also stored inside the permanent memory of the phone, plus it can be physically read if the phone is dissasembled ;)).

I compared several bootloaders from different firmware revisions, and the primary boot loader is unchanged until the version "bundled" in JM1 revision low level package.

The new bootloader(s) were first introduced in "JM1" revision low level factory firmware package. This is the case atleast for generic, unbranded European firmware variants (XF, XW, XX). The firmwares have compile date of 07/21/2010.

In other firmware varians (for different regions) the changes seem to have been made already in earlier versions (JGx) revision firmwares. The estimated date is unknow.

The phones I handled today (which had the "3-button" combos disabled) happened to have I9000XXJM1 FactorySW value ;) What a coincidence.

So why we cannot just downgrade the PBL?

At first the possibility that the PBL cannot be programmed thru USB ran thru my mind, but since it is possible on earlier devices using Odin protocol and even devices with the same application processor (S5PC110 in S8500) I found it highly unlikely.

As far as I can see, the only reason is the partition image table (.pit file) used by Odin. The partition image table tells Odin which image it should program to "KERNEL" partition e.g. The current .pit files contain the required information for all of the images (SBL, SBL2, KERNEL, DBDATAFS, FACTORYFS, PARAM, CACHE, EFS). The only image lacking from the list is PBL (= Primary boot loader).

So if we get a .pit file with this entry, we should be able to downgrade the primary boot loader to version which allows the "3-button combos".

Even the devices which have "3-button combos" disabled can be easily forced to download mode (which is kinda required to downgrade the PBL...). So that is the least of our problems. And I am not using oven to do that (i.e raising the AP temperature past the tJunction value), those guys are just nuts :rolleyes:

Just mess up the partition table with Odin (very easy) and you get to the proper download mode by a special keypress: Boot and wait for the "black screen of death" (:rolleyes:) to show up. Press and hold "volume down, home and power button. Once the screen turns black release the power button, while keeping volume down and home buttons pressed. Your in the PROPER download mode.

God damn, it is late friday night and I´m still here.

Now it is to meet my dear friends from Islay, Scotland ;)