Windows makes it much easier for userland policy agents to plug into WMI than to call raw ACPI methods, so WMI became much more popular as Microsoft made it mor

Windows makes it much easier for userland policy agents to plug into WMI than to call raw ACPI methods, so WMI became much more popular as Microsoft made it more difficult for vendors to ship random kernel drivers. I didn't write the first WMI integration for Linux (that was Carlos Corbacho back in 2008) but I did write various glue drivers - initially for HP because there was one single hotkey on my laptop that fired a WMI event and which Linux couldn't receive, and later the entire Sony hotkey driver which involved a ludicrous number of layers of indirection. WMI is /somewhat/ self describing (there's a method to call to get a compressed binary of a blob that contains method signatures), but unfortunately there's no requirement that anything they call is documented in any way, so it's often still a matter of reading decompiled ACPI bytecode. I have taken psychic damage so you don't have to.