...
Standalone application has direct access to low level libraries – XilSecure & XilFPGA. It can use PMU firmware services using IPI calls to program PL or can write application using XilFPGA and XilSecure library to directly program PL.
As the data provided in user space will be located in virtual space, linux driver before handing off to ATF converts the data buffers to physical address.
The below image shows the high level architecture of image loading via PMU firmware.
...