Breakthrough Made in Windows Phone 7 Custom ROM Quest
An important step has been made towards the goal of building custom Windows Phone 7 ROMs, with skilled coder ansar.ath.gr having reportedly successfully swapped out the imgfs.bin file from a European HTC HD7 with ones from both a Mondrian (HTC 7 Surround) and Asian language Schubert (HD7) ROM, resulting in what he claims are two flashable NBH images. For those unfamiliar with WP7 ROM structures — and really, who isn’t? — the imgfs.bin contains both the SYS and OEM packages, which consist of the core OS files along with drivers and other customizations from the manufacturer, respectively. A tool has been provided in the ROM download ZIPs for what should be a pretty direct flash.
Apparently, by just replacing imgfs.bin instead of trying to build a ROM from the ground up, chefs can bypass the many Genuine Advantage protection mechanisms Microsoft has incorporated into the platform.
However, before you go hooking your Focus or Quantum up to the PC, keep in mind that these images probably won’t even work on non-HTC devices, as the drivers seem specific to the Taiwanese OEM’s hardware. Furthermore, even those HTC WP7 owners probably don’t want to attempt this, as you won’t be gaining any additional features or functionality out of such a hybrid ROM; basically, this is just a proof-of-concept that should eventually lead to custom ROMs once chefs have a better understanding of, and more control over, the packages included in the various ROM subsections.