Method and apparatus for facilitating device hibernation

1. A method for reanimating a computing device from a hibernation image, comprising:

restoring reanimation code from the hibernation image;

executing the reanimation code, wherein executing the reanimation code causes the computing device to restore the rest of the hibernation image by:

reading compressed data containing the rest of the hibernation image;

decompressing the compressed data using computational circuitry within the computing device, wherein the decompression operations are overlapped with the reading operations to improve performance during the reanimation process; and

setting a reanimation flag so that hibernation-aware drivers can determine that a following wake-from-sleep operation is not a normal wake-from-sleep operation, but is instead part of a reanimation operation; and

performing a wake-from-sleep operation to reanimate the computing device from the decompressed hibernation image.

2. The method of claim 1 , wherein restoring the rest of the hibernation image additionally involves:

reading a decryption key from non-volatile random access memory; and

using the decryption key to decrypt portions of the compressed data containing the rest of the hibernation image which were encrypted prior to storage in non-volatile memory.

3. The method of claim 1 , wherein prior to restoring the reanimation code, the method further comprises:

comparing a stored booter checksum, which was stored while generating the hibernation image, against a current booter checksum for a booter which is currently restoring the animation code; and

if the stored booter checksum does not match the current booter checksum, discontinuing the reanimation process.

4. The method of claim 1 , wherein prior to restoring the reanimation code, the method further comprises:

examining stored device configuration information, which was stored when the hibernation image was generated, to determine whether the configuration of the computing device has changed since the hibernation image was generated; and

if the configuration of the computing device has changed, discontinuing the reanimation process.

5. A computing device including a mechanism for reanimating the computing device from a hibernation image, comprising:

a processor;

a memory;

a device-initialization mechanism, which is configured to,

restore reanimation code from the hibernation image;

execute the reanimation code, wherein executing the reanimation code causes the computing device to:

read compressed data containing the rest of the hibernation image;

decompress the compressed data using computational circuitry within the computing device, wherein the decompression operations are overlapped with the reading operations to improve performance during the reanimation process; and

set a reanimation flag so that hibernation-aware drivers can determine that a following wake-from-sleep operation is not a normal wake-from-sleep operation, but is instead part of a reanimation operation; and

perform a wake-from-sleep operation to reanimate the computing device from the decompressed hibernation image.

6. A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for reanimating a computing device from a hibernation image, the method comprising:

restoring reanimation code from the hibernation image; and

executing the reanimation code, wherein executing the reanimation code causes the computing device to restore the rest of the hibernation image by:

reading compressed data containing the rest of the hibernation image;

decompressing the compressed data using computational circuitry within the computing device, wherein the decompression operations are overlapped with the reading operations to improve performance during the reanimation process; and

setting a reanimation flag so that hibernation-aware drivers can determine that a following wake-from-sleep operation is not a normal wake-from-sleep operation, but is instead part of a reanimation operation; and

performing a wake-from-sleep operation to reanimate the computing device from the decompressed hibernation image.

7. The computer-readable storage medium of claim 6 , wherein restoring the rest of the hibernation image additionally involves:

reading a decryption key from non-volatile random access memory; and

using the decryption key to decrypt portions of the compressed data containing the rest of the hibernation image which were encrypted prior to storage in non-volatile memory.

8. The computer-readable storage medium of claim 6 , wherein prior to restoring the reanimation code, the method further comprises:

comparing a stored booter checksum, which was stored while generating the hibernation image, against a current booter checksum for a booter which is currently restoring the animation code; and

if the stored booter checksum does not match the current booter checksum, discontinuing the reanimation process.

9. The computer-readable storage medium of claim 6 , wherein prior to restoring the reanimation code, the method further comprises:

examining stored device configuration information, which was stored when the hibernation image was generated, to determine whether the configuration of the computing device has changed since the hibernation image was generated; and

if the configuration of the computing device has changed, discontinuing the reanimation process.