The source code and extensive documentation are available on the BUSMASTER GitHub repository.
The technical process of bus mastering is a delicate negotiation. When a device, such as a modern network interface card (NIC) or a solid-state drive (SSD) controller, needs to move large blocks of data, it sends a request to the CPU to "arbitrate" for the bus. If the bus is free, the device is granted mastery. Once in control, the bus master independently reads from or writes to the system memory, bypassing the CPU entirely. This process is often referred to as Direct Memory Access (DMA). When the transfer is complete, the bus master relinquishes control and signals the CPU, usually via an interrupt, that the task is finished. busmaster