Solaris on Tecra 550CDT: APM

The first task - setting up the desired laptop behavior with respect to power consumption in different operation modes - is still available from the firmware based TSETUP utility which can be entered every time the system is rebooted (see the Basic Installation page for details).

As to the battery status montoring, you won't get a nice indicator somewhere in the corner, but still the computer will alert you - first with a led on the front panel going yellow from green, and then with beeps - as soon as battery goes too low. Be aware, however, that when the sound alarm (which is what people really start to react to) turns on, you have only 2 to 4 minutes to plug in AC adaptor cord or go to suspend mode; it's quite enough for me, but YMMV, as always.

And the most important and interesting thing: suspend mode. Unlike the most laptops in the past, Toshiba doesn't dump the contents of its memory to a dedicated partition on the HD, but rather preserves all stuff in the RAM "as is" spending a tiny fraction of the usual battery resource for keeping the image alive. This mechanism works independently of the OS used, so it's OK with Solaris, too. Where APM-awareness of the operating system comes into play is when the laptop resumes from the suspend mode: a number of peripherals, in particular PCMCIA cards, do not re-initialize themselves, so if the OS knows that it just resumed and takes care of resetting those devices, then the whole procedure looks completely transprent and hassle-free.

Unfortunately (again), Solaris 2.6 and 7 don't cooperate with the laptop BIOS with respect to suspending/resuming. After returning from the suspend mode, there're three devices that must be re-initialized: PCMCIA NIC and modem and sound. Although technically simple, such a procedure is rather boring for manual execution, so I wrote a shell script hiber that takes care of all such devices before going to and after returning from the suspend mode. Please note that this script is not a generic tool but is made specifically for my laptop configuration: you certainly can use it as an example of what and how should be done, but you should not expect it to work as is on any other system unless it has exactly the same network, modem and sound setup as my Tecra.

I run this script - hiber on - as root once right before suspending the laptop, and one more time - hiber off - immediately after resuming. Before suspending the system, I always make sure that there're no active processes using (generating traffic over) the network or holding open modem or sound devices; otherwise it may not be possible to reset properly the correspondent driver(s) after resuming.

One more thing is worth mentioning here. After returning from the suspend mode, Accelerated-X server's video memory gets corrupted: the screen looks like a set of 8 vertical stripes all displaying the same part of the full screen image. To fight that, I simply switch (with Alt-Ctrl-F2) to another virtual terminal and then immediately switch (with Alt-SysReq, F1) back to the graphical screen used by X server. If you don't know how to activate additional character based virtual terminals, please read this Solaris 2 FAQ article.