像 Windows 或 Linux 这样的现代操作系统如何知道特定于芯片组的 memory Z1D78DC8ED51214E5018B5114

Question

The memory map of the peripherals are defined by the chipset. However, modern operating systems like linux and Windows can boot from pretty much every chip (if compiled for the right architecture). As far as I know, the memory mapped devices like the USB Host are not included in the architecture standard. How can the OS still boot, load the drivers, and function? I suppose there must be some specification where the chipset is described.

Formulated a little different: How does the identification of the chipset work, what standards define the communication between the chipset and the processor so that it works on different hardwares and how does the kernel know the right physical addresses for the different peripherals?

Answer 1

Open systems typically use a device tree , which is a specification of the attached hardware, and how it is attached. There is another system, ACPI which supports legacy PCs. Either system permits an OS to locate and configure the buses and associated peripherals it needs.

It is never 100% as easy as that. For example, it is fine for the OS to know there is a scsi controller on bus 1 at address 1000; but if the code for the scsi driver isn't in the loaded os image, then this knowledge is of little use, as it has no way to load the driver.

The intel specification for ACPI attempts to fix this by having tiny driver implementations baked into the firmware of either the platform, the device itself, or both. Since the device doesn't necessarily know what sort of cpu it will run on, these mini drivers are written in a virtual instruction set which the host OS requires an interpreter for.

UEFI provides an alternate way have addressing the boot dependency via a more generic mechanism to use mini-boot drivers for the same purpose.