Dynamic management of a memory firewall

A method of managing memory access, comprising:

• receiving, at a firewall device, an access request for a memory area, the access request having a security level indication;
• comparing, by a verification circuit of the firewall device, the security level indication with access rights information stored in a set of registers associated with the memory area;
• selectively authorizing or prohibiting the access request based on the comparison and a current configuration mode of the firewall device;
• receiving, from a non-secure processing unit, a configuration command at a configuration interface of the firewall device;
• and
• switching the configuration mode of the firewall device between:
• a first mode authorizing secure and non-secure access requests to the memory area, and
• a second mode authorizing non-secure access requests and prohibiting secure access requests to the memory area.

A firewall device, comprising:

• a plurality of firewall circuits, each associated with a respective memory area and comprising:
• a set of registers containing access rights information for the associated memory area;
• a verification circuit configured to compare security level indications of access requests with the access rights information;
• and
• a configuration interface, wherein at least a first firewall circuit of the plurality is configurable, via its configuration interface, by a non-secure processing unit to operate in:
• a first mode authorizing secure and non-secure access requests to its associated memory area, and
• a second mode authorizing non-secure access requests and prohibiting secure access requests to its associated memory area.