System and method for using a using vendor-long descriptor in ACPI for the chipset registers

• US 20040030854A1
• Filed: 08/07/2002
• Published: 02/12/2004
• Est. Priority Date: 08/07/2002
• Status: Active Grant

• Current Assignee: MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Qureshi, Shiraz A., Nicholes, Martin O.
• Granted Patent: US 6,792,520 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: G06F 9/4411 Configuring for operating with peripheral devices; Loading of device drivers

Abstract

A system and method for using memory mapped I/O (MMIO) to manage system devices is provided. A parent device in the ACPI namespace uses (MMIO) to identify the memory addresses of its children devices. An existing, but unused, construct of ACPI is used to pass the MMIO information through the operating system (OS) to the device drivers, enabling memory to be reserved by a device, and also remain hidden to the OS. The vendor defined resource data type for long information, also known as the “vendor-long” descriptor, is used to pass the appropriate information through the OS.

Claims

1. A mechanism for hiding memory from an operating system, where the memory is owned by a device and is allocated using memory mapped I/O (MMIO), comprising:

a computer system connected to a plurality of devices, wherein an operating system interacts with the plurality of devices using Advanced Configuration and Power Interface (ACPI);

a memory block connected to the computer system, wherein the memory block is allocated to the plurality of devices to provide an MMIO register map for device interaction; and

means for hiding regions of memory from the operating system, the hidden memory being allocated to at least one of the plurality of devices, wherein the hidden memory is accessible to at least one tool, the tool interacting with at least one of the devices having allocated hidden memory.

2. The mechanism as recited in claim 1, wherein the tool is a device driver.

3. The mechanism as recited in claim 1, wherein means for hiding regions of memory uses a variable length ACPI data object to pass information regarding the hidden memory, wherein the operating system ignores the information passed in the variable length ACPI data object.

4. The mechanism as recited in claim 3, wherein variable length ACPI data object is a previously defined ACPI vendor-long data object.

5. The mechanism as recited in claim 4, wherein the computer system uses IA-64 instruction set architecture.

6. A method of using memory mapped I/O (MMIO) to manage system devices, comprising:

allocating memory in a computer system to a plurality of devices, the memory corresponding to a register map of the plurality of devices;

identifying areas of allocated memory that should be hidden from the operating system, the hidden areas being accessible by at least one tool interacting with at least one of the plurality of devices; and

enabling an operating system running on the computer system to view selected memory allocations of MMIO, the operating system ignoring the hidden areas of allocated memory.

7. The method as recited in claim 6, wherein enabling an operating system to view selected memory allocations, comprises:

receiving a current status data object of a resource, wherein the current status returns information corresponding to memory allocations of devices and resources available to the operating system; and

receiving a vendor-long data object of a resource, wherein the vendor-long returns information corresponding to memory allocations of devices and resources hidden form the operating system.

8. The method as recited in claim 7, further comprising passing the vendor-long data to a tool, by the operating system, wherein the tool utilizes the hidden memory allocation information.

9. The method as recited in claim 8, wherein the tool is a device driver.

10. The method as recited in claim 6, wherein the computer system uses IA-64 instruction set architecture.

11. A computing device using memory mapped I/O (MMIO) for hiding selected regions of mapped memory from an operating system, comprising:

a central processing unit (CPU) having memory;

a memory bus connecting the CPU with a plurality of devices, wherein the memory bus comprises data, address and control information, wherein an operating system interacts with the plurality of devices using Advanced Configuration and Power Interface (ACPI);

a memory block connected to the CPU, wherein the memory block is allocated to the plurality of devices to provide an MMIO register map for device interaction; and

means for hiding regions of memory from the operating system, the hidden memory being allocated to at least one of the plurality of devices, wherein the hidden memory is accessible to at least one tool, the tool interacting with at least one of the devices having allocated hidden memory.

12. The computing device as recited in claim 11, wherein the tool is a device driver.

13. The computing device as recited in claim 11, wherein means for hiding regions of memory uses a variable length ACPI data object to pass information regarding the hidden memory, wherein the operating system ignores the information passed in the variable length ACPI data object.

14. The computing device as recited in claim 13, wherein variable length ACPI data object is a previously defined ACPI vendor-long data object.

15. The computing device as recited in claim 14, wherein the computing device uses IA-64 instruction set architecture.

16. The computing device as recited in claim 15, wherein the computing device is a personal computer (PC).