[x86] (2) Post Mortem: ACPI/ SCI/ Q Event

Before we back to the Future world full of mobile and smart devices, let's take a look on those old bones from yesterday world...however, as the latest news I know, there are still a huge bunch of Taiwan engineers devoted their self to the x86 based, nearly dead PC and NB markets and refuse to wake up. It's really sucks that our human nature tends to follow, not to lead. Anyway, pretend you're visiting the x86 museum....with my sarcasm introduce.

 Long long time ago, there is a power saving standard called APM, the main idea is that any devices besides the CPU might notify CPU through SMI (software or hardware wired) that CPU would run the power state modify routine written in BIOS code. SMIs can't be scheduled well since it's nothing to do with OS that the system would halt while CPU's dealing with SMIs.

Well, it sucks to be so technique. Let's do it over again, CPU is a poor cook, only dealing one customer's order at one time. However, there are a bunch of crazy supervisors, they could interrupt cooker's job in the name of SMI. So the poor cook got customer complaint and supervisor take it as their huge contribution as management level.

Boring questions you guys must know the answers.

More boring history.

ACPI's so complicated...Really? The main idea is as simple as the poor cook example in APM.

I really like this page that I draw before, however it's too detailed on ACPI events. If anyone's interested, I would append the explanation as demand.

This is my favorite page that I update it several times! Too bad it's still detailed, but I would point one thing take-away, ACPI is like the poor cook in previously example, hires one sexy waitress (that is Operating System!) to assist the order schedule including the non-sense requests from stupid supervisors. The SMI requests mentioned previously are now replaced by SCI requests.

Huh, boring power states. Can you image that all those years go by and still the general users got confused on all those damn S3/S4/S5/S0/Hibernate/Fast-Start-Up/ Connected-Stand-By things... No one really sees what are they doing and they didn't even recognize it...wow!

More Reference...

More questions... make it stop!

Good trip of old stuff, right? I had devoted a lot time and efforts on it, but now I realize that I shouldn't only learn for the job and money, or there goes the consequences that most things you know became the yesterday's ashes. At least I wake up now, ha ha.

Any questions, suggestions or comments, please show me some support, thanks!