Patent ID: 8725999

Claim:
An integrated circuit comprising: a processor; a primary boot ROM storing primary boot code; a plurality of external pins operatively coupled to the processor; and a writable non-volatile memory operatively coupled to the processor, the memory having a plurality of regions each for storing one or more respective boot properties for booting said processor, wherein at least some of the plurality of regions are permanently written with one or more boot properties representing boot options; wherein the processor is configured to initiate booting by executing the primary boot code, the primary boot code containing code which when executed causes the processor to select one of said regions in which a boot option is permanently written in dependence on an indication received via one or more of said external pins, to retrieve the one or more respective boot properties from the selected region, and to continue booting using the one or more retrieved boot properties, wherein: the one or more boot properties in each region comprise at least an identifier of a respective source of secondary boot code and at least one additional respective parameter to specify properties or options related to the identified source; and the processor is programmed to retrieve the respective identifier from the selected region, and to boot from the source of secondary boot code identified by the retrieved identifier in dependence on the at least one additional parameter.