10.30.2012

Funtoo Linux and Intel Rapid Start Technology

Recently I got myself a new laptop of NEC's Lavie Z (LZ550/H). It's really a nice laptop, weights only 875g in its 13.3" size. NEC said it is the world's most lightweight 13.3" laptop ever been.

The laptop encompasses an Intel 7 series chipset UM77 which supports Intel Rapid Start, a technology let the laptop goes into the deeper ACPI S4 (hibernate) from ACPI S3 (standby) after some periods of time.

It differs from that the hibernation is directly supported in the hardware, so that you will not see any traditional boot sequences during waking up from a hibernated machine as before, just a flash. It seems Apple implements Safe Sleep by the use of it in their Macs.

The laptop runs linux (Funtoo Linux) and I found out no instructions about how to setup Intel Rapid Start up with linux. But it ends up being not too complicated:
  • an SSD
  • an BIOS supports Intel Rapid Start Technology
  • a partition equal or greater than the laptop's physical memory
I use gdisk to create an extra 4GB partition since the laptop is 4GB model, and then you must give the partition a specified id as to be recognized by the hardware. According to Intel and Gigabyte's manuals, it must be:
  • in diskpart, id: 84, or
  • in gdisk, guid: D3BFE2DE-3DAF-11DF-BA40-E3A556D89593


After that you can reboot the machine into BIOS and check whether the Intel Rapid Start Technology options is on. If you see something like "No valid IFFS partition found" then there must be something wrong in the previous partitioning step.


Now you can see in the BIOS there are additional options can be configured the Rapid Start. Since Intel releases no software for Linux currently, you can only configure it via BIOS.

To test if it works, configure it to "Entry Imemediately", and make your latop go into S3 standby:

# echo -n mem > /sys/power/state
  1. it goes into standby.
  2. it wake up immediately after standby.
  3. then it will flush memory contents into the partition.
  4. goes into hibernation.
  5. you can only wake it up by pressing the power button.
  6. after powering up again, you are now at where you were as if it had never powered down.

I've just set it up for hours, don't know whether it is stable yet, but it did work. I'm at vanilla-sources-3.6.3 with CK patches.

There are some times that it goes into hibernation immediately while I setup up a 5 mins period, and there are some times that it wake up from first S3 but not going to hibernation anymore..., since I just got my Funtoo prototype without any further settings for ACPI/laptop, I cannot make sure it's my problem or not.

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