System and method for providing instant video in an information handling system
Before initializing a memory of an information handling system, a method includes loading an image of a video option ROM code for a graphics interface device to a cache associated with a processor of the information handling system, and executing the video option ROM code to initialize the graphics interface device. The method also includes executing a memory reference code to initialize the memory, and while executing the memory reference code, providing status information from the graphics interface device.
1. A method comprising:
prior to initializing a memory of an information handling system:
loading an image of a video option read-only memory (ROM) code to a cache, wherein the video option ROM is for a graphics interface device of the information handling system and the cache is associated with a processor of the information handling system, and wherein the image of the video option ROM code is loaded from a basic input/output (BIOS) ROM device associated with the information handling system; and
executing by the processor the video option ROM code to initialize the graphics interface, wherein executing the video option ROM code further comprises:
fetching instructions of the video option ROM code from the BIOS ROM device; and
executing write instructions of the video option ROM code to the cache;
executing a memory reference code to initialize the memory; and
while executing the memory reference code, providing from the graphics interface device status information related to the information handling system.
2. The method of claim 1 , further comprising loading a basic input/output system data area to the cache prior to initializing the memory.
3. The method of claim 1 , further comprising loading a vector table to the cache prior to initializing the memory.
4. The method of claim 1 , wherein:
the image of the video option ROM code is loaded to the BIOS ROM device from an option ROM device associated with the graphics interface device.
5. The method of claim 1 , wherein further the video option ROM code includes instructions to write to a first memory location, the first memory location being within a block of the cache that includes the image of the video option ROM code.
6. The method of claim 1 , wherein further the video option ROM code includes instructions to read from a second memory location, the second memory location being within a block of the cache that includes the image of the video option ROM code.
7. The method of claim 1 , wherein further the processor is configured such that if code in the cache is fetchable, then the cache is not writeable, and if the cache is writeable, then the code in the cache is not fetchable.
8. The method of claim 1 , wherein the video option ROM code in the BIOS ROM device comprises a modified version of an original video option ROM code from an option ROM device associated with the graphics interface.
9. An information handling system, comprising:
a processor including a cache, the cache operable in a cache-as-RAM mode;
a graphics interface including video option read only memory (ROM) code; and
a basic input/output system (BIOS) ROM device including the video option ROM code;
a memory;
wherein:
the cache is set to the cache-as-RAM mode;
an image of the video option ROM code is fetched from the BIOS ROM device by the processor and stored in the cache;
the video option ROM code is executed by the processor, the execution of the video option ROM operating to initialize the graphics interface, wherein in executing the video option ROM code, the processor operates to:
fetch the video option ROM code from the BIOS ROM device; and
execute write instructions of the video option ROM code to the ache;
after the graphics interface is initialized, the processor executes a memory reference code to initialize the memory; and
while initializing the memory, the processor directs the graphics interface to display status information.
10. The information handling system of claim 9 , wherein further a basic input/output system (BIOS) data area is stored in the cache prior to fetching and storing the image of the video option ROM.
11. The information handling system of claim 9 , wherein further a vector table is stored in the cache prior to fetching and storing the image of the video option ROM.
12. The information handling system of claim 9 , wherein:
the image of the video option ROM code is fetched to the BIOS ROM device from an option ROM device associated with the graphics interface.
13. The information handling system of claim 9 , wherein further the video option ROM code includes instructions to write to a first memory location, the first memory location being within a block of the cache that includes the image of the video option ROM code.
14. The information handling system of claim 9 , wherein further the video option ROM code includes instructions to read from a second memory location, the second memory location being within a block of the cache that includes the image of the video option ROM code.
15. The information handling system of claim 9 , wherein further the processor is configured such that if code in the cache is fetchable, then the cache is not writeable, and if the cache is writeable, then the code in the cache is not fetchable.
16. The information handling system of claim 9 , wherein the video option ROM code in the BIOS ROM device comprises a modified version of an original video option ROM code from an option ROM device associated with the graphics interface.
17. A method comprising:
reading a video option read only memory (ROM) code from a graphics interface device;
executing the video option ROM code;
comparing the video option ROM code from before the execution with the video option ROM code from after the execution to determine a location within the video option ROM code that is a data storage location;
finding an instruction within the video option ROM code that accesses the data storage location;
modifying the video option ROM code such that the instruction accesses a different storage location;
storing the modified video option ROM code on a basic input/output system ROM of an information handling system; and
providing that the information handling system executes the modified video option ROM code prior to initializing a memory of the information handling system.
18. The method of claim 17 , wherein the instruction, when executed on the information handling system, accesses a data storage location that is within a cache of a processor of the information handling system.