Quick Question about how an OS allocates RAM to Hardware devices
Hi all, not sure if this is the correct place for this question, so apologies if not.
I am learning about computers, and am having difficulty understanding something.
When a hardware device such as a hard drive wishes to send data, which has been requested by a user using an application. (Example, opening a word document that is saved on hard drive in MS Word)
What is the basic process/workflow for the data going from the hard drive, to the RAM and CPU and then to the application?
I was reading something and this is the part which I am having issues understanding.
"Memory is the playing field where hardware and software mix. Memory management
is the responsibility of the OS. The OS makes sure that the hardware
and software components work within their own confines of memory. As
memory resources are requested, the OS releases them either to the hardware
device driver or to the application."
I understand the OS allocates memory for each application to execute and run in, but im not sure how the OS gives memory to Hardware devices. Does this mean if the hard drive has some data to send to the CPU, the OS allocates that piece of hardware some memory so the hardware can send the data there before the CPU takes it from RAM and processes it??
Apologies about this, im a little confused.