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operating-systemcpuhardwarerambios

How does my operating system get information about disk size, RAM size, CPU frequency, etc

I can see from my OS the informations about my hard disk, RAM and CPU. But I've never told my OS these info.

  1. How does my OS know it?
  2. Is there some place in the hard disk or CPU or RAM that stores this kind of information?
  3. Is there some standard about the format of this kind of information?
Solution

  • SMBIOS (formerly known as DMI) contains much of this information. SMBIOS is a a data structure/API that is part of the BIOS/UEFI firmware and contains info like brand and model of the computer, etc.

    The rest is gathered by the OS querying hardware directly.