Safe software revision for embedded systems

• US 20080270677A1
• Filed: 06/30/2003
• Published: 10/30/2008
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Kolakowski, Mikolaj
• Granted Patent: US 7,512,749 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 8/60 Software deployment

Abstract

The present invention, in one embodiment includes identifying a first partition of an embedded program memory, reading a description associated with the first partition, identifying a second partition of an embedded program memory, reading a description associated with the second partition, comparing descriptions, selecting an embedded program memory partition using the comparison, and writing program code to the selected program memory partition.

Claims

1. A method comprising:

identifying a first partition of an embedded program memory;

reading a description associated with the first partition;

identifying a second partition of an embedded program memory;

reading a description associated with the second partition;

comparing descriptions;

selecting an embedded program memory partition using the comparison; and

writing program code to the selected program memory partition.

2. The method of claim 1, wherein reading a description comprises reading a value of an upgrade counter register.

3. The method of claim 2, wherein the upgrade counter register value comprises a time stamp.

4. The method of claim 1, wherein reading a description comprises reading a flag that indicates whether the software in the partition is valid.

5. The method of claim 2, wherein the program code is an upgraded program code and wherein selecting an embedded program memory partition comprises selecting the embedded program memory partition corresponding to the older of the upgrade counter values.

6. The method of claim 2, further comprising incrementing the upgrade counter value corresponding to the selected program memory portion.

7. The method of claim 1, wherein writing program code comprises writing a code invalid marker and wherein selecting an embedded program memory partition comprises selecting a program memory partition containing newer stored program code.

8. The method of claim 7, further comprising decrementing an upgrade counter for the selected embedded memory partition.

9. The method of claim 1, further comprising checking the written program code in the selected embedded program memory partition for errors and, if no errors are found, then incrementing an upgrade counter corresponding to the selected upgrade memory counter.

10. The method of claim 1, further comprising setting a flag during writing program code.

11. A machine-readable medium having stored thereon data representing instructions which, when executed by a machine, cause the machine to perform operations comprising:

identifying a first partition of an embedded program memory;

reading a description associated with the first partition;

identifying a second partition of an embedded program memory;

reading a description associated with the second partition;

comparing descriptions;

selecting an embedded program memory partition using the comparison; and

writing program code to the selected program memory partition.

12. The medium of claim 11, wherein the instructions for reading a description comprise instructions which, when executed by the machine, cause the machine to perform further operations comprising reading a value of an upgrade counter register.

13. The medium of claim 11, wherein the instructions for reading a description comprise instructions which, when executed by the machine, cause the machine to perform further operations comprising reading a flag that indicates whether the software in the partition is valid.

14. The medium of claim 12, wherein the program code is an upgraded program code and wherein the instructions for selecting an embedded program memory partition comprise instructions which, when executed by the machine, cause the machine to perform further operations comprising selecting the embedded program memory partition corresponding to the older of the upgrade counter values.

15. The medium of claim 11, wherein the instructions for writing program code comprise instructions which, when executed by the machine, cause the machine to perform further operations comprising writing a code invalid marker and wherein the instructions for selecting an embedded program memory partition comprise instructions which, when executed by the machine, cause the machine to perform further operations comprising selecting a program memory partition containing newer stored program code.

16. An apparatus comprising:

an embedded program memory having a first partition and a second partition;

a register to store a description associated with the first partition;

a register to store a description associated with the second partition; and

a processor to identify the first partition and the second partition, to read the stored descriptions associated with the first partition and the second partition, to compare descriptions, to select a partition using the comparison, and to write program code to the selected program memory partition.

17. The apparatus of claim 16, wherein the description register comprises an upgrade counter register.

18. The apparatus of claim 17, wherein the upgrade counter register comprises a time stamp register.

19. The apparatus of claim 16, wherein the description register comprises a flag register to indicate whether the software in the partition is valid.

20. The apparatus of claim 16, wherein the processor is further to check the written program code in the selected embedded program memory partition for errors and, if no errors are found, then increment an upgrade counter correspond to the selected upgrade memory counter.

21. The apparatus of claim 16, wherein the processor is further to set a flag during writing program code.

22. A system comprising:

a flash memory having a first partition and a second partition;

an upgrade counter to store a count associated with the first partition;

an upgrade counter to store a count associated with the second partition;

a bus coupled to the flash memory and the counters;

an I/O interface coupled to the bus to communicate data to external components; and

a processor coupled to the bus to identify the first partition and the second partition, to read the upgrade counters, to compare the upgrade counts, to select a partition using the comparison, and to write program code to the selected program memory partition.

23. The system of claim 22, further comprising a validity flag for the first partition and a validity flag for the second partition and wherein the processor reads the validity flags can applies the validity flag values to select a partition.

24. The system of claim 22, wherein the program code is an upgraded program code and wherein the processor selects a partition by selecting the partition corresponding to the older of the upgrade counter values.

25. The system of claim 22, wherein the processor writes program code by writing a code invalid marker and wherein the processor selects a partition by selecting a partition containing newer stored program code.