Patent ID: 7409539

Claim:
A method for managing boot code of a computer system, wherein the system comprises at least a first and a redundant second boot memory portion, and wherein the system is booted from one of said portions, referred to as an active boot memory portion, other boot memory portion being in a stand-by mode and being referred to as inactive boot memory portion, characterized by the steps of: 1a) booting the system from said first one of said two boot memory portions; 1b) verifying correctness of a boot procedure; 1c) re-booting from said second boot memory portion and if correct; 1d) replicating the boot code from the active boot memory portion to the inactive boot memory portion; and 1e) running normal operation mode; and wherein a boot code sequence is stored at the inactive boot memory portion for safe boot code update procedures which are activated from an alternative boot memory portion of the inactive boot memory portion, which boot code update procedures comprise the sequence of steps as follows: 2a) booting the system from said alternative boot memory portion; 2b) verifying the correctness of the boot procedure, and if not correct, 2c1) re-booting from a standard boot memory portion, and 2c2) replicating the boot code from the active boot memory portion to the inactive boot memory portion, if correct, 2d) storing a piece of additional invalidation code, which makes the alternative boot memory portion the active boot memory portion, at a predetermined memory location of the standard boot memory portion, which is updated last by the subsequent replicating step, 2e) replicating the boot code from the alternative boot memory portion to the standard boot memory portion; and 2f) booting from said standard boot memory portion.