TrustZone Technology Overview
http://www.arm.com/products/esd/trustzone_home.html

TrustZone API Overview
http://www.arm.com/products/esd/trustzone_apioverview.html

TrustZone Cores
http://www.arm.com/products/esd/trustzone_cores.html

TrustZone Software
http://www.arm.com/products/esd/trustzone_software.html

TrustZone System Design
http://www.arm.com/products/esd/trustzone_systemdesign.html

Achieving Stronger SIM-lock and IMEI Implementations on Open Terminals using ARM TrustZone® Technology>> (123Kb .pdf)
http://www.arm.com/miscPDFs/15500.pdf