The doesn’t have anything to do with the language code was written in. Ultimately all software is assembly. This is about hardware specific registers that control the underlying hardware and can be used for things like controlling oem functionality (brightness, backlight, etc), changing CPU frequency and voltage, etc.
> This is about hardware specific registers that control the underlying hardware and can be used for things like controlling oem functionality (brightness, backlight, etc)
That sort of functionality is typically handled by the platform controller by sending commands over LPC or I2C busses. CPU MSRs are generally restricted to controlling the behavior of the CPU itself.
> changing CPU frequency and voltage, etc.
These are often controlled by MSRs, but should be under the direct control of the kernel, not userspace software.
Which also doesn't mean you can't write software that does those things (within reason and as configured by the kernel). It just means that you will have to use the appropriate kernel interfaces, as you already should have been.
