The sources on the cupcake branch on the open source repository already include support for ARMv4T
I don't exactly what ARMv4i is (it's not listed on
http://www.arm.com/products/CPUs/architecture.html),
but it looks like to be similar. Moreover, the OpenMoko folks have ported the Android kernel to run on
the FreeRunner which is ARMv4T, so I assume that what you're looking for is possible.