System and method for a pseudo DLL linker

• US 20070130565A1
• Filed: 01/18/2006
• Published: 06/07/2007
• Est. Priority Date: 12/01/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Budhati, Vani, Ingles, Roger, Fan, Guoxin
• Granted Patent: US 7,735,075 B2
• Time in Patent Office: Days
• US Class Current: 717/173
• CPC Class Codes: G06F 8/54 Link editing before load time
• CPC Class Codes: G06F 9/44563 Sharing

Abstract

The present disclosure relates generally to a system and method for a pseudo DLL linker. In one example, the method includes identifying a plurality of components forming an image and identifying all symbols exportable from each component and all symbols imported by each component from another component. A redirection mechanism is built containing an address of each symbol exported by a component that is imported by another component, and each component is modified to alter each direct reference to a symbol associated with another component to a reference to the redirection mechanism. A linker is called to link a final image based on the modified components.

Claims

1. A method for providing a monolithic image for use in a wireless device, the method comprising:

identifying a plurality of components forming an image represented in machine code;

for each component of the plurality of components, building an export symbol list containing all symbols within the component that are accessible to other components and an import symbol list containing all symbols within other components that are needed by the component;

building a redirection mechanism containing an indirect reference to each symbol in each component'"'"'s export symbol list that is in the import symbol list of at least one other component;

for each component of the plurality of components, altering each direct reference to a symbol in another component to refer to the indirect reference associated with the symbol in the redirection mechanism, wherein references internal to a component are not altered; and

creating a final image containing the altered components and the redirection mechanism.

2. The method of claim 1 further comprising defining at least one criterion for a component in a component description file for use in identifying the plurality of components.

3. The method of claim 2 further comprising determining whether the component description file exists for use in identifying the plurality of components.

4. The method of claim 3 further comprising using at least one default component definition to identify the plurality of components if there is no component description file.

5. The method of claim 1 wherein building the redirection mechanism includes creating at least one jump table.

6. The method of claim 1 wherein building the redirection mechanism includes creating at least one veneer.

7. The method of claim 1 wherein the image represented in machine code is received directly from an assembler and wherein the final image is created by calling a linker normally called directly by the assembler.

8. The method of claim 1 further comprising transferring the image to the wireless device using a firmware over the air process.

9. A method for providing an executable image for a mobile device, the method comprising:

receiving an image from an assembler;

identifying a plurality of components forming the image;

identifying all symbols exportable from each component and all symbols imported by each component from another component;

building a redirection mechanism containing an address of each symbol exported by a component that is imported by another component;

modifying each component to alter each direct reference to a symbol associated with another component to a reference to the redirection mechanism; and

calling a linker to link a final image based on the modified components.

10. The method of claim 9 wherein the identifying the plurality of components uses at least one component definition contained in a component description file prepared by a user.

11. The method of claim 9 wherein the identifying the plurality of components uses at least one component definition contained in a default description file.

12. The method of claim 9 wherein a symbol is a variable or a function.

13. The method of claim 9 wherein at least one of the plurality of components includes a plurality of modules, the method further comprising grouping the plurality of modules to form the component.

14. A method comprising:

building at least first and second components from a plurality of modules forming an image received in machine language code;

building an export symbol list and an import symbol list for each of the first and second components;

comparing the first component'"'"'s export symbol list with the second component'"'"'s import symbol list and comparing the second component'"'"'s export symbol list with the first component'"'"'s import symbol list to identify any symbols that are on the export list of one of the first and second components and the import list of the other of the first and second components;

building a redirection mechanism containing a location of each identified symbol; and

modifying the first component to change each reference to an export symbol of the second component to a reference to the redirection mechanism and modifying the second component to change each reference to an export symbol of the first component to a reference to the redirection mechanism.

15. The method of claim 14 further comprising calling a linker to create an executable image based on the modified components and the redirection mechanism.

16. The method of claim 14 further comprising organizing the plurality of modules into the first and second component based on a predefined set of component definitions.

17. A static monolithic image for a mobile device that is controlled by an operating system that does not support dynamic linking or dynamic sharing, the image comprising:

at least one redirection mechanism containing an address of each symbol within the image that is imported by any component forming the image from any other component forming the image; and

a plurality of components, wherein each component has a direct reference to any symbol contained by the component itself, and has a reference to the redirection mechanism for any symbol imported from another component.

18. The image of claim 17 wherein each symbol is a variable or a function.

19. The image of claim 17 wherein the redirection mechanism includes at least one jump table.

20. The image of claim 17 wherein the redirection mechanism includes at least one veneer.

21. A system comprising:

a processor;

a memory unit coupled to the processor; and

a plurality of instructions stored on the memory unit for execution by the processor, the instructions including instructions for;

converting a monolithic image for use with a wireless device from assembly code to machine code;

building a plurality of components based on modules identified in the machine code;

identifying each symbol exportable by each component and each symbol imported by each component;

building a redirection mechanism containing every symbol that is exportable by one component and imported by another component;

modifying each component to alter each reference to an export symbol associated with another component to a reference to the redirection mechanism; and

linking the modified components and the redirection mechanism to create a final version of the monolithic image.

22. The system of claim 21 further comprising means for transferring the final version of the monolithic image to the wireless device.