In simple individual cases the CMSIS-Core Files can be delivered to developers as part of example projects and SDKs. But the most scalable approach with improved usability is to provide them packaged in Open-CMSIS-Pack format, and this page explains how to do this.

The CMSIS-Core Standard Files are provided as part of CMSIS Software pack under CMSIS class of components and compose there the CORE group.

The CMSIS-Core Device Files are delivered in CMSIS Device Family Packs (DFPs) that provide necessary mechanisms for device support in embedded software. The DFPs are typically maintained by device vendors.

Since Device Header File <Device.h> does not need to be modified in the project, it can be made accessible with its include path.

For uniform experience, the files Startup File startup_<Device>.c and System Configuration Files system_<Device>.c and system_<Device>.h should be provided in the DFP as part of Device class in the Startup group and defined as configuration files, meaning they are copied from the pack into a project folder and can be modifed there if necessary.

Below is an example of how CMSIS-Core device files can be defined in a .pdsc file of DFP pack, based on the implementation for a generic Cortex-M55 device.

<components>
  <!-- CMSIS-Startup components -->
  
  <!-- Cortex-M55 -->
  <component Cclass="Device" Cgroup="Startup" Cvariant="C Startup" Cversion="2.2.0" condition="ARMCM55 CMSIS" isDefaultVariant="true">
    <description>System and Startup for Generic Cortex-M55 device</description>
    <files>
      <!-- include folder / device header file -->
      <file category="include" name="Device/ARMCM55/Include/"/>
      <!-- startup / system file -->
      <file category="sourceC" name="Device/ARMCM55/Source/startup_ARMCM55.c"   version="1.1.0" attr="config"/>
      <file category="sourceC" name="Device/ARMCM55/Source/system_ARMCM55.c"    version="1.1.0" attr="config"/>
      <!-- SAU configuration -->
      <file category="header"  name="Device/ARMCM55/Config/partition_ARMCM55.h" version="1.0.0" attr="config" condition="TZ Secure"/>
    </files>
  </component>
  
</components>

Since the CMSIS-Core Device Files require access to implementations from CMSIS-Core Standard Files, the Device Family Packs need to specify the dependency on CMSIS:CORE component. In the code above this is done with the condition="ARMCM55 CMSIS" that is defined in the same .psdc file as:

<conditions>
  
  <condition id="ARMCM55 CMSIS">
    <description>Generic Arm Cortex-M55 device startup and depends on CMSIS Core</description>
    <require Dvendor="ARM:82" Dname="ARMCM55*"/>
    <require Cclass="CMSIS" Cgroup="CORE"/>
  </condition>
  
</conditions>

Device Examples

The Cortex_DFP pack provides generic device definitions for standard Arm Cortex-M cores and contains corresponding CMSIS-Core Device Files.

These files can be used as a reference for device support in a DFP pack, but can also be used in projects that require standard Arm processors functionality. See Use generic Arm Devices.

Looking at other Device Family Packs can be also helpful to understand the CMSIS-Core support with DFPs. The list of public CMSIS packs (including DFPs) can be found at keil.arm.com/packs.