Method for flashing ESCD and variables into a ROM

• US 6,073,206 A
• Filed: 04/30/1998
• Issued: 06/06/2000
• Est. Priority Date: 04/30/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Piwonka, Mark A., Hobson, Louis B., Hess, Randall L., Kane, Jeffrey D.
• Primary Examiner(s): Yoo, Do Hyun
• Assistant Examiner(s): GOODARZI, NASSER MOAZZAMI
• Application Number:
  US09/070,866
• Time in Patent Office: 768 Days
• Field of Search: 711/102, 711/103, 711/161, 711/162, 711/170, 714/4, 714/5, 714/6, 395/653, 707/202, 707/203, 707/204
• US Class Current: 711/102
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A computer system for flashing Extended System Configuration Data (ESCD) and associated variables to a flash read-only memory (ROM) is provided. During Power-On-Self-Test (POST) code, a ROM image is copied from an ESCD sector of a read-only memory to an ESCD original buffer and an ESCD write buffer. The ESCD write buffer may be updated by POST code. Following the POST operations, the contents of the ESCD write buffer are copied to an ESCD runtime buffer. The contents of the ESCD original buffer or the ESCD sector are compared to the contents of the ESCD runtime buffer. If the contents of the ESCD runtime buffer differ from the contents of the compared buffer or sector, SMI code flashes the ROM image in the ESCD runtime buffer to the flash ROM. If the ESCD runtime buffer is the same as the contents of the compared buffer or sector, a ROM flash it not performed. POST is then exited and the computer system is booted. During runtime, if a write is performed to ESCD data or an associate variable, the ESCD runtime buffer is updated with the ESCD data or variable provided for the write operation. The SMI code then flashes the ROM image in the ESCD runtime buffer into the ESCD sector to save the ESCD data or variable provided by the write operation.

Claims

1. A method of flashing an extended system configuration data (ESCD) storage area of a non-volatile memory of a computer system comprising the steps of:

copying a non-volatile memory image of an ESCD data storage area for storing ESCD and associated variables of a non-volatile memory to a first region of a power on self test (POST) buffer and a second region of the POST buffer;

copying contents of the second region of the POST buffer to an ESCD runtime buffer;

comparing the contents of the first region of the POST buffer or the ESCD data storage area of the non-volatile memory with the contents of the ESCD runtime buffer; and

flashing the non-volatile memory image in the ESCD runtime buffer into the ESCD data storage area during the system management mode of the computer system if the contents of the ESCD runtime buffer differ from the contents of the compared first region of the POST buffer or the ESCD data storage area.

2. The method of claim 1, further comprising the steps of:

detecting an update to the ESCD runtime buffer during runtime; and

flashing the non-volatile image in the ESCD runtime buffer into the ESCD data storage area of the non-volatile memory.

3. The method of claim 1, further comprising the step of:

updating the first region of the POST buffer during POST before the step of copying the contents of the second region of the POST buffer to the ESCD runtime buffer.

4. The method of claim 1, wherein the non-volatile memory is a flash read-only memory.

5. The method of claim 1, wherein the POST buffer is an area of random access memory existing during POST.

6. The method of claim 1, wherein the ESCD runtime buffer is an area of random access memory existing during POST and runtime.

7. The method of claim 1, wherein the associated variables comprise variables representing system features or ownership data.

8. The method of claim 1, further comprising the step of:

entering a system management mode of the computer system from a 16-bit protected mode of the computer system before the step of flashing the non-volatile image.

9. The method of claim 1, further comprising the step of:

entering a system management mode of the computer system from a 32-bit protected mode of the computer system before the step of flashing the non-volatile image.

10. The method of claim 1, further comprising the step of:

entering a system management mode of the computer system from a real mode of the computer system before the step of flashing the non-volatile image.

11. A computer system for flashing an extended system configuration data (ESCD) storage area of a non-volatile memory comprising:

a non-volatile memory, comprising storage locations for;

an ESCD data storage area for storing ESCD data and associated variables;

a non-volatile memory BIOS storage area for storing BIOS code for generating an system management interrupt (SMI) flash for the ESCD data storage area of the non-volatile memory; and

an SMI storage area for storing SMI code for flashing the ESCD data storage area of the non-volatile memory responsive to generation of a system management interrupt by the BIOS code;

during Power on self test (POST) or during runtime responsive to a write to the ESCD data and associated variables and

a processor for executing the BIOS code.

12. The computer system of claim 11, further comprising:

a volatile memory storing the BIOS code during execution of the BIOS code.

13. The computer system of claim 11, further comprising:

a volatile memory storing the SMI code during execution of the SMI code.

14. The computer system of claim 11, wherein the non-volatile memory is a flash read-only memory.

15. The computer system of claim 11, wherein the associated variables comprise variables representing system features or ownership data.

16. A computer system for flashing an extended system configuration data (ESCD) and associated variables into a non-volatile memory, comprising:

a non-volatile memory, comprising storage locations for;

an ESCD data storage area for storing ESCD data and associated variables;

power on self test (POST) code storage area for storing POST code for initializing the computer system;

an system management interrupt (SMI) code storage area for storing SMI code for flashing a non-volatile memory image into the ESCD data storage area; and

an ESCD flash code storage area for storing ESCD flash code for flashing said ESCD data and said associated variables during POST and runtime;

a volatile memory, comprising;

an ESCD original buffer for storing said ESCD data and said associated variables during POST;

an ESCD runtime buffer for storing said ESCD data and said associated variables during runtime;

an ESCD write buffer for providing said ESCD data and said associated variables to the ESCD runtime buffer during the POST; and

a processor executing the ESCD flash code to perform the steps of;

copying the non-volatile memory image of the ESCD data storage area to the ESCD original buffer and ESCD write buffer;

copying the contents of the ESCD write buffer to the ESCD runtime buffer;

comparing the contents of the ESCD original buffer or the ESCD data storage area with the contents of the ESCD runtime buffer; and

flashing the non-volatile memory image in the ESCD runtime buffer into the ESCD data storage area if the contents of the ESCD runtime buffer differ from the contents of the compared ESCD original buffer or the ESCD data storage area.

17. The computer system of claim 16, the processor executing the ESCD flash code to perform the further step of:

updating the ESCD write buffer with the POST code before the step of copying the contents of the ESCD write buffer to the ESCD runtime buffer.

18. The computer system of claim 16, the processor executing the ESCD flash code to perform the further steps of:

detecting an update to the ESCD runtime buffer; and

flashing the non-volatile memory image in the ESCD runtime buffer into the ESCD data storage area.

19. The computer system of claim 16, wherein the non-volatile memory is a flash read-only memory.

20. The computer system of claim 16, wherein the ESCD original buffer is a random access memory area existing during the POST.

21. The computer system of claim 16, wherein the ESCD write buffer is a random access memory area existing during the POST.

22. The computer system of claim 16, wherein the ESCD runtime buffer is a random access memory area existing during the POST and the runtime.

23. The computer system of claim 16, wherein the step of flashing the non-volatile memory image to the ESCD data storage area comprises the step of:

executing the SMI code for flashing a non-volatile memory image into the ESCD data storage area.

24. The computer system of claim 16, wherein the associated variables comprise variables representing system features or ownership data.