It's time now to tackle the Galaxy S2(Exynos) platform. A lot of lessons were learned last time.. So we'll start this thing off by saying that it looks like they've removed UART functionality in this edition of Samsung processors. I can understand why... We were able to access a root prompt when the kernel loaded up to charge the battery, as well as clear the download counts, flash partitions and have other full access to the Serial Administration Console... So, it looks like there's no UART available.
I took the liberty of creating the Galaxy S2 Hack Pack which will help out. This contains the Public processor manual, the i9100 service manual and a ton of other helpful tools.
Contained within the Level 3 service manual was a processor pinout with each pin labeled. I yanked that out of the processor manual, put it into GIMP, flipped it, labeled it prepaired it. This contains all the pins and they're labeled.. but they're small, so I enlarged the ones we're concerned with.
Here's the i9100 board. I obtained this great image from ifixit.
Now, we can apply the overlay to the board and....
Now if we look to the left in the picture above we can see that there are 5 resistor switches. The right side is low and the left side is high. there are 3 high, 1 low and 1 disconnected.
The Development board for this processor shows only 5 switches though, 2 of the 7 signals we are concered with (xOM0 and xOM6) are hardwired and non-switchable. This leaves a promissing 5 switches.. However I don't know what to make of the one which is disconnected. Logically the shortest path would apply here and look something like this:
So, since xOM5 switched boot mode from OneNAND to UART>USB>OneNAND on the Hummingbird.. Considering xOM6 doesn't count on this device.. I'm thinking xOM5 could control boot mode on this device as well.
Any input? I have a i9100 here.