Systems and methods to extend ROM functionality

摘要

Various embodiments allow for flexible and secure updates of drivers for numerous types of external memory devices by utilizing an address-selection mechanism within a simple and secure ROM code to enable the loading of a dynamic routine from an external source into a dynamic memory. In certain embodiments, the routine enables a simple and trusted framework to access and modify the content of any number of complex memory devices via simple commands without affecting existing security measures. This increases the usable lifetime of secure ROM code, simplifies device validation, and shortens the overall development cycle by extending the functionality of secure ROM code while keeping the ROM code and any programming thereof simple.

主权项

1. A system to extend the functionality of a ROM code, the system comprising:
a ROM of a device coupled to receive data and an address range, the ROM comprises the ROM code that in response to receiving the address range makes a selection regarding a target location where to write the data, the selection regarding the target location being based on a determination by the ROM code as to whether the address range is addressed by the ROM code; and a secure memory coupled to the ROM, being internal to the device and being recognized by the ROM code, the ROM code being extended by selecting a routine that is accessed from the secure memory, the ROM code optionally selects:
a first routine accessed from and performed by the ROM code to write the data to the secure memory if the address range is addressed by the ROM code, anda second routine accessed from and performed by the secure memory to write the data to an external memory if the address range is addressed by the secure memory.