Boot validation system and method
View Patent ↗A boot validation system and method may be used in a computer system to validate boot code before allowing the computer system to execute the boot code. In particular, a secure hash algorithm may be used to compute a hash value of the boot code and the computed hash value may be compared to a preprogrammed hash value stored in a secure non-volatile device. If the hash values match the boot code may be validated and the system may then be allowed to execute the boot code. Once the boot code is validated, the boot code may be executed to validate other code (e.g., firmware) in the computer system. In an exemplary embodiment, the boot validation systems and method may be used in an imaging device, such as a printer.
1. A method for boot validation in an image forming device including at least one central processing unit (CPU), comprising:
holding at least said CPU in reset in response to a power on signal to prevent said CPU from executing at least boot code upon powering on said image forming device;
retrieving said boot code from a firmware storage device, said firmware storage device storing said boot code together with other executable code including firmware other than boot code;
computing a hash value of said boot code;
retrieving a preprogrammed hash value from a secure non-volatile device;
comparing said computed hash value with said preprogrammed hash value; and
allowing said image forming device to execute said boot code if said computed hash value matches said preprogrammed hash value.
2. The method of claim 1 wherein said boot code includes tamper detection code to validate other firmware.
3. The method of claim 1 wherein said hash value is computed using a secure hash algorithm.
4. The method of claim 1 further comprising executing said boot code to validate other firmware.
5. The method of claim 1 further comprising inhibiting operation of at least one component of said image forming device if said computed hash value does not match said preprogrammed hash value.
6. The method of claim 1 further comprising holding a system Application Specific Integrated Circuit (ASIC) in reset.
7. The method of claim 1 wherein said method for boot validation is performed by a cartridge configured for use in the image forming device.
8. The method of claim 1 wherein holding at least said CPU in reset, retrieving said boot code, computing said hash value, retrieving said preprogrammed hash value, and comparing said computed hash value with said preprogrammed hash value are performed by an Application Specific Integrated Circuit (ASIC).
9. The method of claim 1 wherein holding at least said CPU in reset, retrieving said boot code, computing said hash value, retrieving said preprogrammed hash value, and comparing said computed hash value with said preprogrammed hash value are performed by a boot validation device.
10. The method of claim 1 wherein said firmware storage device includes programmable non-volatile memory.