If the source is a bank-switched device

In this scenario, the image is stored in a device that isn't directly mapped into linear memory. An additional factor needs to be considered here — how will your IPL code get at the image stored in the device?

Many types of hardware devices conform to this model:

Let's look at the common characteristics. In such systems, the IPL code knows how to fetch data from some piece of hardware. The process is as follows:

  1. The IPL receives control.
  2. The IPL loads the image from the hardware into RAM.
  3. The IPL then transfers control to the newly loaded image.
Figure 1. Bank-switched devices.