Nios® II Software Developer Handbook

ID 683525
Date 8/28/2023
Public
Document Table of Contents

8.8.3.3.2. No Specific Requests

If no specific device driver is requested, and no compatible device driver is located for a particular hardware module, the BSP generator issues an informative message visible in either the debug or verbose generation output. This behavior is normal for many types of hardware, such as memory devices, that do not have device drivers. If a software package or specific driver is requested and cannot be located, an error is generated and BSP generation or settings update halts.

Creating a Tcl script allows you to add extra definitions in the system.h file, enable automatic driver initialization through the alt_sys_init.c structure, and enable the Nios® II SBT to control any extra parameters that might exist.

With the Tcl software definition files in place, the SBT reads in the Tcl file and populate the makefiles and other support files accordingly.

When the Nios® II SBT adds each driver or software package to the system, it uses the data in the Tcl script defining the driver or software package to control each file copied in to the BSP. This rule also affects generated BSP files such as the BSP Makefile, public.mk, system.h, and the BSP settings and summary HTML files.

When you create a new software project, the Nios® II SBT generates the contents of alt_sys_init.c to match the specific hardware contents of the system.