Method and apparatus for preserving the integrity of a management subsystem environment
View Patent ↗A computer system includes various security measures to insure that semi-permanent operating programs, such a boot blocks and firmware, are updated properly. For example, the system may include a security switch that can enable a host computer to load a replacement program into another computer, such as an appliance server for example, if the other computer fails. Also, if a replacement program is being loaded over a network connection that fails, the loading can resume automatically after re-establishment of the network connection. In addition, certain programs, such as boot blocks, may be verified in an execution memory, such as RAM, and loaded into a more permanent storage memory, such as ROM, only if verified.
1. A computer system comprising:
a host computer;
an appliance server operably coupled to the host computer, the appliance server having a storage memory and an execution memory;
a control operably coupled to the appliance server and to the storage memory to control storage of programs into the storage memory, the appliance server being adapted to replace a first program stored in the storage memory with a second program by loading the second program into the storage memory, wherein the appliance server is further adapted to verify the second program stored in the storage memory, wherein verifying comprises authenticating the second program and determining whether the second program is operable, and wherein the appliance server is further adapted to reload the first program into the storage program if the second program is not verified and to execute the second program if the if the second program is verified; and
a security device operably coupled to the control, the security device being adapted to signal the control to permit the host computer to store the second program in the storage memory, the security device comprising a switch, wherein the second program is stored in the storage memory only if the switch is enabled.
2. The computer system, as set forth in claim 1 , wherein the storage memory comprises a read only memory.
3. The computer system, as set forth in claim 1 , wherein the storage memory comprises a non-volatile memory.
4. The computer system, as set forth in claim 1 , wherein the storage memory comprises a flash memory.
5. The computer system, as set forth in claim 1 , wherein the execution memory comprises a random access memory.
6. The computer system, as set forth in claim 1 , wherein the execution memory comprises a volatile memory.
7. A method of operating a computer system, the method comprising the acts of:
during operation of a computer executing a first program in an execution memory and having a copy of the first program stored in a storage memory, replacing the first program stored in the storage memory with a second program by loading the second program into the storage memory;
verifying the second program stored in the storage memory, wherein verifying comprises the acts of authenticating the second program and determining whether the second program is operable; and
if verified, executing the second program,
if not verified, reloading the first program from the execution memory into the storage memory.
8. The method, as set forth in claim 7 , wherein the execution memory comprises a random access memory.
9. The method, as set forth in claim 7 , wherein the execution memory comprises a volatile memory.
10. The method, as set forth in claim 7 , wherein the storage memory comprises a read only memory.
11. The method, as set forth in claim 7 , wherein the storage memory comprises a non-volatile memory.
12. The method, as set forth in claim 7 , wherein the storage memory comprises a flash memory.
13. The method, as set forth in claim 7 , comprising the act of enabling a switch, wherein the second program is loaded into the storage memory only if the switch is enabled.
14. The method, as set forth in claim 7 , wherein the first and second programs comprise boot block programs.
15. The method, as set forth in claim 7 , wherein the first and second programs comprise firmware programs.