Method and system for trusted/untrusted digital signal processor debugging operations

• US 8,533,530 B2
• Filed: 11/15/2006
• Issued: 09/10/2013
• Est. Priority Date: 11/15/2006
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Codrescu, Lucian, Anderson, William C., Venkumahanti, Suresh, Giannini, Louis Achille, Pyla, Manojkumar, Chen, Xufeng
• Primary Examiner(s): CHU, GABRIEL L
• Application Number:
  US11/560,332
• Publication Number:
  US 20080115011A1
• Time in Patent Office: 2,491 Days
• Field of Search: None
• US Class Current: 714/21
• CPC Class Codes: G06F 11/3656 using a specific debug interface

Abstract

Techniques for the design and use of a digital signal processor, including (but not limited to) for processing transmissions in a communications (e.g., CDMA) system. Trusted and untrusted debugging operational control occurs in operating a core processor associated with the digital signal processor. A debugging process within a debugging mechanism associates with the core processor. The core processor process determines the origin of debugging control as trusted debugging control or untrusted debugging control. In the event of trusted debugging control, the core processor process provides to the trusted debugging control a first set of features and privileges. Alternatively, in the event that debugging control is untrusted debugging control, the core processor process provides the untrusted debugging control a second restricted set of features and privileges, all for maintaining security and proper operation of the core processor process.

Claims

1. A method, comprising:

determining a debug mode of one or more threads of a multi-threaded processor based on a trust value stored at a system configuration register; and

providing a first set of debugging features and privileges when the debug mode is a first debug mode and a second set of debugging features and privileges when the debug mode is a second debug mode,

wherein providing the first set of debugging features and privileges includes granting unrestricted write control for a debugging command register, and

wherein providing the second set of debugging features and privileges includes restricting writing any command to the debugging command register other than an interrupt command.

2. The method of claim 1, wherein each of a plurality of threads is debugged independently of other threads of the plurality of threads.

3. The method of claim 1, wherein the first debug mode is entered when a bit of the system configuration register indicates the trust value as trusted, and wherein the second debug mode is entered when the bit indicates the trust value untrusted.

4. The method of claim 3, wherein the first set of debugging features and privileges includes read/write control for non-intrusive debugging configuration registers.

5. The method of claim 3, wherein the first set of debugging features and privileges includes write control for debugging breakpoint configuration registers.

6. The method of claim 3, wherein the first set of debugging features and privileges includes write control for debugging breakpoint address registers.

7. The method of claim 3, wherein the first set of debugging features and privileges includes write control for instruction stuffing registers.

8. The method of claim 3, wherein the first set of debugging features and privileges and the second set of debugging features and privileges include read/write control for a mailbox for debugging mechanism registers.

9. The method of claim 3, wherein the first set of debugging features and privilege includes read/write control for debugging mechanism general purpose registers.

10. The method of claim 3, wherein the first set of debugging features and privileges and the second set of debugging features and privileges include read control for debugging mechanism enable registers.

11. The method of claim 3, wherein the trust value is set by an operating system.

12. The method of claim 1, wherein the one or more threads are each configured to operate in a plurality of modes including a wait non-processing mode and a debug non-processing mode, and wherein the one or more threads are each operable to transition between the debug non-processing mode and the wait non-processing mode.

13. The method of claim 12, wherein the plurality of modes further include a user processing mode, a supervisor processing mode, and an off non-processing mode.

14. The method of claim 13, wherein the one or more threads are each operable to transition between the debug non-processing mode an any mode of the plurality of modes other than the off non-processing mode, and wherein a particular thread of the one or more threads is powered down in response to receiving a breakpoint while the particular thread is operating in the off non-processing mode.

15. The method of claim 1, wherein providing the second set of debugging features and privileges further includes restricting access to debugging configuration registers, breakpoint registers, and a stuff instruction register, granting read control to a mailbox-in register, granting write control to a mailbox-out register, granting read/write control to a debugging enable register, granting read control to a debugging version register, and restricting access to a debugging general purpose register.

16. A system comprising:

a system configuration register having a core processor control bit, the core processor control bit operative to determine a debug mode of one or more threads of a multi-threaded processor; and

instructions for providing a first set of debugging features and privileges when the debug mode is a first debug mode and a second set of debugging features and privileges when the debug mode is a second debug mode,

wherein the instructions for providing the first set of debugging features and privileges include instructions for granting unrestricted write control for a debugging command register, and

wherein the instructions for providing the second set of debugging features and privileges include instructions for restricting writing any command to the debugging command register other than an interrupt command.

17. The system of claim 16, wherein the first debug mode is entered when the core processor control bit indicates a trust value as trusted, and wherein the second debug mode is entered when the core processor control bit indicates the trust value as untrusted.

18. The system of claim 17, further comprising circuitry and instructions for providing read/write control for non-intrusive debugging configuration registers in the first debug mode.

19. The system of claim 17, further comprising circuitry and instructions for providing write control for debugging breakpoint configuration registers in the first debug mode.

20. The system of claim 17, further comprising circuitry and instructions for providing write control for debugging breakpoint address registers in the first debug mode.

21. The system of claim 17, further comprising circuitry and instructions for providing write control for instruction stuffing registers in the first debug mode.

22. The system of claim 17, further comprising circuitry and instructions for providing read/write control for mailbox to debugging mechanism registers in the first debug mode and in the second debug mode.

23. The system of claim 17, further comprising circuitry and instructions for providing read/write control for debugging mechanism general purpose registers in the first debug mode.

24. The system of claim 17, further comprising circuitry and instructions for providing read control for debugging mechanism enable registers in the first debug mode and in the second debug mode.

25. The system of claim 17, wherein the core processor control bit is set by an operating system.

26. A multi-threaded digital signal processor comprising:

means for determining a debug mode of one or more threads of a multi-threaded processor based on a trust value stored at a system configuration register; and

means for providing a first set of debugging features and privileges when the debug mode is a first debug mode and a second set of debugging features and privileges when the debug mode is a second debug mode,

wherein the means for providing the first set of debugging features and privileges include means for granting unrestricted write control for a debugging command register, and

wherein the means for providing the second set of debugging features and privileges include means for restricting writing any command to the debugging command register other than an interrupt command.

27. The multi-threaded digital signal processor of claim 26, wherein the first debug mode is entered when a bit of the system configuration register indicates the trust value as trusted, and wherein the second debug mode is entered when the bit indicates the trust value as untrusted.

28. The multi-threaded digital signal processor of claim 27, further comprising means for providing read/write control for non-intrusive debugging configuration registers in the first debug mode.

29. The mufti-threaded digital signal processor of claim 27, further comprising means for providing write control for debugging breakpoint configuration registers in the first debug mode.

30. A non-transitory computer usable medium having computer readable program code means embodied therein for processing instructions on a multi-threaded digital signal processor for debugging the multi-threaded digital signal processor, the computer usable medium comprising:

computer readable program code means for determining a debug mode of one or more threads of a multi-threaded processor based on a trust value stored at a system configuration register; and

computer readable program code means for providing a first set of debugging features and privileges when the debug mode is a first debug mode and a second set of debugging features and privileges when the debug mode is a second debug mode,

wherein the computer readable program code means for providing the first set of debugging features and privileges include computer readable program code means for granting unrestricted write control for a debug in command register, and

wherein the computer readable program code means for providing the second set of debugging features and privileges include computer readable program code means for restricting writing any command to the debugging command register other than an interrupt command.