Retrieving boot instructions from nonvolatile memory

• US 8,533,448 B2
• Filed: 12/06/2010
• Issued: 09/10/2013
• Est. Priority Date: 04/10/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wu, Stephen
• Primary Examiner(s): Cao, Chun
• Application Number:
  US12/961,449
• Publication Number:
  US 20110078432A1
• Time in Patent Office: 1,009 Days
• Field of Search: 713/1, 713/2
• US Class Current: 713/2
• CPC Class Codes: G06F 1/24 Resetting means
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/4403 Processor initialisation
• CPC Class Codes: G06F 9/4406 Loading of operating system
• CPC Class Codes: G06F 9/44573 Execute-in-place [XIP]

Abstract

Systems and processes for booting a device can be implemented by detecting a reset signal associated with the device and retrieving a predetermined page of data from a nonvolatile memory location into a register associated with the nonvolatile memory. The nonvolatile memory may be designed and implemented such that each page of data is retrieved from the nonvolatile memory as a unit, and the page of data includes instructions for use in booting the device. A command to read data stored in the register is received, and the command can include an address identifying a location of one or more instructions within the register. In response, the one or more instructions are retrieved from the register for execution by a processor.

Claims

1. A method for booting a device, the method comprising:

detecting a reset signal associated with the device; and

in response to detecting the reset signal;

retrieving, by an internal controller that is a part of a nonvolatile memory apparatus, a predetermined page of data from a location in the nonvolatile memory apparatus, wherein each page of data is retrieved from the nonvolatile memory as a unit and the page of data includes at least one instruction for booting the device;

loading, by the internal controller, the predetermined page including the at least one booting instruction into a register associated with the nonvolatile memory apparatus;

receiving, by the internal controller, a command from a host processor coupled to the nonvolatile memory apparatus to read data stored in the register, wherein the command includes an address identifying a location within the register of the at least one booting instruction;

retrieving the at least one instruction from the register by the internal controller;

transmitting the at least one instruction from the internal controller to the host processor without storing the data in another memory; and

determining, by the internal controller, if the booting instructions are complete and ending the process if it is complete or continuing to receive additional commands from the host processor if the booting is not complete.

2. The method of claim 1, the nonvolatile memory comprises a NAND flash memory.

3. The method of claim 1, wherein retrieving a predetermined page of data is performed automatically in response to detecting the reset signal.

4. The method of claim 1, further comprising receiving a plurality of commands to read data stored in the register, wherein the data read in response to the plurality of commands comprises code for loading separate boot loader code to a random access memory associated with the processor.

5. The method of claim 4, wherein the separate boot loader code is adapted for loading operating system or application code from the nonvolatile memory to the random access memory.

6. The method of claim 1, wherein the nonvolatile memory is adapted to enable random access to any byte in the register in response to a command to read data stored in the register.

7. The method of claim 1, further comprising converting an instruction fetch command from the processor into at least one command to read data stored in the register.

8. The method of claim 1 wherein retrieving subsequent booting instructions is performed by the host processor reading from a Random Access Memory (RAM) of the device for executing an operating system and software applications.

9. A computer-accessible non-transitory storage medium having program instructions therein that, in response to execution by a system, cause the system to perform operations comprising:

detecting a reset signal associated with the system; and

in response to detecting the reset signal;

retrieving a predetermined page of data from a location in a nonvolatile memory device by an internal controller included in the nonvolatile memory device, wherein each page of data is retrieved from the nonvolatile memory as a unit and the page of data includes at least one instruction for booting the system;

loading, by the internal controller, the predetermined page including the at least one booting instruction into a register associated with the nonvolatile memory device;

receiving, by the internal controller, a command from a host processor coupled to the nonvolatile memory device to read data stored in the register, wherein the command includes an address identifying a location within the register of the at least one booting instruction;

retrieving the at least one instruction from the register by the internal controller;

transmitting the at least one instruction from the internal controller to the host processor without storing the data in another memory; and

determining, by the internal controller, if the booting instructions are complete and ending the process if it is complete or continuing to receive additional commands from the host processor if the booting is not complete.

10. The medium of claim 9, wherein the nonvolatile memory comprises a NAND flash memory.

11. The medium of claim 9, wherein retrieving a predetermined page of data is performed automatically in response to detecting the reset signal.

12. The medium of claim 9, the instructions for causing data processing apparatus to perform operations further comprising receiving a plurality of commands to read data stored in the register, wherein the data read in response to the plurality of commands comprises code for loading separate boot loader code to a random access memory associated with the processor.

13. The medium of claim 12, wherein the separate boot loader code is adapted for loading operating system or application code from the nonvolatile memory to the random access memory.

14. The medium of claim 9, wherein the nonvolatile memory is adapted to enable random access to any byte in the register in response to a command to read data stored in the register.

15. The medium of claim 9, the instructions for causing data processing apparatus to perform operations further comprising converting an instruction fetch command from the processor into at least one command to read data stored in the register.

16. The medium of claim 9 wherein retrieving subsequent booting instructions is performed by the host processor reading from a Random Access Memory (RAM) of the device for executing an operating system and software applications.

17. A data processing apparatus comprising:

a host having a host processor;

a non-volatile memory device that is separate from the host and that is configured to store data for the host, wherein the non-volatile device includes;

one or more non-volatile memory blocks;

a register; and

an internal controller configured to;

detect a reset signal; and

in response to detecting the reset signal;

retrieve a predetermined page of data from a location in nonvolatile memory location, wherein each page of data is retrieved from the nonvolatile memory as a unit and the page of data includes at least one instruction for booting the data processing apparatus;

load the predetermined page including the at least one booting instruction into the register;

receive a command from the host processor to read data stored in the register, wherein the command includes an address identifying a location within the register of the at least one booting instruction;

retrieve the at least one instruction from the register; and

transmit the at least one instruction from the internal controller to the host processor without storing the data in another memory; and

determine if the booting instructions are complete and end the process if it is complete or continue to receive additional commands from the host processor if the booting is not complete.

18. The apparatus of claim 17, wherein the nonvolatile memory comprises a NAND flash memory.

19. The apparatus of claim 17, wherein retrieving a predetermined page of data is performed automatically in response to detecting the reset signal.

20. The apparatus of claim 17, the instructions for causing data processing apparatus to perform operations further comprising receiving a plurality of commands to read data stored in the register, wherein the data read in response to the plurality of commands comprises code for loading separate boot loader code to a random access memory associated with the processor.

21. The apparatus of claim 20, wherein the separate boot loader code is adapted for loading operating system or application code from the nonvolatile memory to the random access memory.

22. The apparatus of claim 17, wherein the nonvolatile memory is adapted to enable random access to any byte in the register in response to a command to read data stored in the register.

23. The apparatus of claim 17, the instructions for causing data processing apparatus to perform operations further comprising converting an instruction fetch command from the processor into at least one command to read data stored in the register.

24. The apparatus of claim 17 wherein subsequent booting instructions are retrieved from a Random Access Memory (RAM) of the device for executing an operating system and software applications.