ARM supplies CMSIS-CORE template files for the all supported Cortex-M processors and various compiler vendors. Refer to the list of Tested and Verified Toolchains for compliancy. These template files include the following:

Register names of the Core Peripherals and names of the Core Exception Vectors.
Functions to access core peripherals, special CPU instructions and SIMD instructions (for Cortex-M4)
Generic startup code and system configuration code.

The detailed file structure of the CMSIS-CORE is shown in the following picture.

CMSIS-CORE File Structure

Template Files

The CMSIS-CORE template files should be extended by the silicon vendor to reflect the actual device and device peripherals. Silicon vendors add in this context the:

Device Peripheral Access Layer that provides definitions for device-specific peripherals.
Access Functions for Peripherals (optional) that provides additional helper functions to access device-specific peripherals.
Interrupt vectors in the startup file that are device specific.

Template File	Description
".\Device_Template_Vendor\Vendor\Device\Source\ARM\startup_Device.s"	Startup file template for ARM C/C++ Compiler.
".\Device_Template_Vendor\Vendor\Device\Source\GCC\startup_Device.s"	Startup file template for GNU GCC ARM Embedded Compiler.
".\Device_Template_Vendor\Vendor\Device\Source\G++\startup_Device.s"	Startup file template for GNU Sourcery G++ Compiler.
".\Device_Template_Vendor\Vendor\Device\Source\IAR\startup_Device.s"	Startup file template for IAR C/C++ Compiler.
".\Device_Template_Vendor\Vendor\Device\Source\system_Device.c"	Generic system_Device.c file for system configuration (i.e. processor clock and memory bus system).
".\Device_Template_Vendor\Vendor\Device\Include\Device.h"	Generic device header file. Needs to be extended with the device-specific peripheral registers. Optionally functions that access the peripherals can be part of that file.
".\Device_Template_Vendor\Vendor\Device\Include\system_Device.h"	Generic system device configuration include file.

In addition ARM provides the following core header files that do not need any modifications.

Core Header Files	Description
core_<cpu>.h	Defines the core peripherals and provides helper functions that access the core registers. This file is available for all supported processors: core_cm0.h: for the Cortex-M0 processor core_cm0plus.h: for the Cortex-M0+ processor core_cm3.h: for the Cortex-M0 processor core_cm4.h: for the Cortex-M0 processor core_sc000.h: for the SecurCore SC000 processor core_sc300.h: for the SecurCore SC300 processor
core_cmInstr.h	Defines intrinsic functions to access special Cortex-M instructions.
core_cmFunc.h	Defines functions to access the Cortex-M core peripherals.
core_cm4_simd.h	Defines intrinsic functions to access the Cortex-M4 SIMD instructions.

Adaption of Template Files to Devices

Copy the complete folder including files and replace:

folder name 'Vendor' with the abbreviation for the device vendor e.g.: NXP.
folder name 'Device' with the specific device name e.g.: LPC17xx.
in the filenames 'Device' with the specific device name e.g.: LPC17xx.

Each template file contains comments that start with ToDo: that describe a required modification. The template files contain placeholders:

Placeholder	Replaced with
<Device>	the specific device name or device family name; i.e. LPC17xx.
<DeviceInterrupt>	a specific interrupt name of the device; i.e. TIM1 for Timer 1.
<DeviceAbbreviation>	short name or abbreviation of the device family; i.e. LPC.
Cortex-M#	the specific Cortex-M processor name; i.e. Cortex-M3.

The adaption of the template files is described in detail on the following pages: