Reclaiming and reusing pre-boot reserved memory post-boot

Patent metadata

Field	Value
Publication number	US-11720401-B2
Application number	US-202016832372-A
Country	US
Kind code	B2
Filing date	Mar 27, 2020
Priority date	Mar 27, 2020
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

Described is a system where memory can be allocated for use by an adapter pre-boot and preserved for use post-boot. A BIOS can allocate for pre-boot hardware operations (e.g., graphics drivers, framebuffers, etc.) and mark this allocated memory as preserved. An indication of the allocated memory can be provided for an OS, such that post-boot, the OS can reclaim and reallocate this memory.

First claim

What is claimed is:

1. A computing apparatus, comprising:
a processor; and
a memory storing instructions, which when executed by the processor, cause the processor to:
allocate a portion of memory dynamically for use by graphics circuitry during pre-boot of an operating system for use by a graphics output protocol (GOP) framebuffer;
mark the portion of the memory as preserved to store graphics information for the graphics circuitry during the pre-boot of the operating system and reclaimable by the operating system during post-boot of the operating system; and
provide an indication of the portion of the memory for the operating system such that the portion of the memory dynamically allocated during the pre-boot of the operating system can be reclaimed by the operating system during the post-boot of the operating system, wherein the reclaimed portion of memory is available for reallocation by the operating system for post-boot operations.

2. The computing apparatus of claim 1 , the instructions, when executed by the processor, cause the processor to dynamically allocate the portion of memory based on the GOP framebuffer contents.

3. The computing apparatus of claim 1 , the instructions, when executed by the processor, cause the processor to populate a graphics translation table (GTT) based on a memory address of the portion of memory.

4. The computing apparatus of claim 1 , the instructions, when executed by the processor, cause the processor to provide a memory address of the portion of memory as the indication.

5. The computing apparatus of claim 1 , the GOP framebuffer arranged to store video display data.

6. The computing apparatus of claim 1 , the instructions, when executed by the processor, cause the processor to mark the portion of the memory as a preserved memory type specified by a unified extensible firmware interface (UEFI) Specification.

7. The computing apparatus of claim 6 , the preserved memory type an EfiPreservedMemoryType.

8. A non-transitory computer-readable storage medium, the computer-readable storage medium including instructions that when executed by circuitry, cause the circuitry to:
allocate a portion of memory dynamically for use by graphics circuitry during pre-boot of an operating system for use by a graphics output protocol (GOP) framebuffer;
mark the portion of the memory as preserved to store graphics information for the graphics circuitry during the pre-boot of the operating system and reclaimable by the operating system during post-boot of the operating system; and
provide an indication of the portion of the memory for the operating system such that the portion of the memory dynamically allocated during the pre-boot of the operating system can be reclaimed by the operating system during the post-boot of the operating system, wherein the reclaimed portion of memory is available for reallocation by the operating system for post-boot operations.

9. The computer-readable storage medium of claim 8 , the instructions, when executed by the circuitry, cause the circuitry to dynamically allocate the portion of memory based on the GOP framebuffer contents.

10. The computer-readable storage medium of claim 8 , the instructions, when executed by the circuitry, cause the circuitry to populate a graphics translation table (GTT) based on a memory address of the portion of memory.

11. The computer-readable storage medium of claim 8 , the instructions, when executed by the circuitry, cause the circuitry to provide a memory address of the portion of memory as the indication.

12. The computer-readable storage medium of claim 8 , the GOP framebuffer arranged to store video display data.

13. The computer-readable storage medium of claim 8 , the instructions, when executed by the circuitry, cause the circuitry to mark the portion of the memory as a preserved memory type specified by a unified extensible firmware interface (UEFI) Specification.

14. The computer-readable storage medium of claim 13 , the preserved memory type an EfiPreservedMemoryType.

15. A method, comprising:
dynamically allocating a portion of memory for use by graphics circuitry during pre-boot of an operating system for use by a graphics output protocol (GOP) framebuffer;
marking the portion of the memory as preserved to store graphics information for the graphics circuitry during the pre-boot of the operating system and reclaimable by the operating system during post-boot of the operating system; and
providing an indication of the portion of the memory for the operating system such that the portion of the memory dynamically allocated during the pre-boot of the operating system can be reclaimed by the operating system during the post-boot of the operating system, wherein the reclaimed portion of memory is available for reallocation by the operating system for post-boot operations.

16. The method of claim 15 , wherein the portion of memory is dynamically allocated based on the GOP framebuffer contents.

17. The method of claim 15 , comprising populating a graphics translation table (GTT) based on a memory address of the portion of memory.

18. The method of claim 15 , comprising providing a memory address of the portion of memory as the indication.

19. The method of claim 15 , the GOP framebuffer arranged to store video display data.

20. The method of claim 15 , comprising marking the portion of the memory as a preserved memory type specified by the UEFI Specification.

21. The method of claim 20 , the preserved memory type an EfiPreservedMemoryType.

Assignees

• Intel Corp

Inventors

• Rajagopal Pannerkumar
• Iyengar Murali R
• Kotary Karunakara
• Pir Ovais
• Pawar Sagar C
• Pillai Prakash
• N Raghavendra
• Tuljapurkar Aneesh A

Classifications

• G06F9/5016 Primary

  the resource being the memory · CPC title

• G06F9/4406 Primary

  Loading of operating system · CPC title

• G06F9/544

  Buffers; Shared memory; Pipes · CPC title

• G06F12/1009

  using page tables, e.g. page table structures · CPC title

• G06T1/60

  Memory management · CPC title