Migrating CMSIS-Packs to CMSIS v6: Device support

Migrating CMSIS-Packs to CMSIS v6

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Migrating CMSIS-Packs to CMSIS v6

Supported toolchains

CMSIS v6 supports the following toolchains:

Before migrating your project, please make sure that you use one of these toolchains. In this learning path, you will use the Arm Compiler for Embedded v6 toolchain.

Update the device support

To update the device support, you will need to follow the steps outlined below:

Switch from assembly based code to C-based startup files .
Create scatter files to place the stack and heap .
Update the pack with the new contents.

Create C-based startup code

In CMSIS v6, assembly-based startup code is deprecated. You must move your startup_device.s files to startup_device.c. This section explains the necessary steps.

Copy the startup_ARMCMx.c file from the CMSIS-DFP repo into your device support repo. In this example, a Cortex-M4-based device is used (and therefore, the startup_ARMCM4.c is taken from CMSIS-DFP/Device/ARMCM4/source).

Copy all the interrupt handler names and wrap them into void handler_name (void) __attribute__ ((weak, alias("Default_Handler")));. Place them around line 58 of the template file.

Code Example

    

        
        
; Interrupt Handlers for Service Requests (SR) from Peripherals */
                Entry   SCU_0_IRQHandler            ; Handler name for SR SCU_0     
                Entry   ERU0_0_IRQHandler           ; Handler name for SR ERU0_0    
                Entry   ERU0_1_IRQHandler           ; Handler name for SR ERU0_1    
                Entry   ERU0_2_IRQHandler           ; Handler name for SR ERU0_2    
                Entry   ERU0_3_IRQHandler           ; Handler name for SR ERU0_3     
                Entry   ERU1_0_IRQHandler           ; Handler name for SR ERU1_0    
                Entry   ERU1_1_IRQHandler           ; Handler name for SR ERU1_1    
                Entry   ERU1_2_IRQHandler           ; Handler name for SR ERU1_2    
                Entry   ERU1_3_IRQHandler           ; Handler name for SR ERU1_3    
                DCD     0                           ; Not Available                 
                DCD     0                           ; Not Available                 
                DCD     0                           ; Not Available                 
                Entry   PMU0_0_IRQHandler           ; Handler name for SR PMU0_0    
                DCD     0                           ; Not Available                 
                Entry   VADC0_C0_0_IRQHandler       ; Handler name for SR VADC0_C0_0  
                Entry   VADC0_C0_1_IRQHandler       ; Handler name for SR VADC0_C0_1  
                Entry   VADC0_C0_2_IRQHandler       ; Handler name for SR VADC0_C0_1  
                Entry   VADC0_C0_3_IRQHandler       ; Handler name for SR VADC0_C0_3

Translates to:

    

        
        
void SCU_0_IRQHandler      (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU0_0_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU0_1_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU0_2_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU0_3_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU1_0_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU1_1_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU1_2_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void ERU1_3_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void PMU0_0_IRQHandler     (void) __attribute__ ((weak, alias("Default_Handler")));
void VADC0_C0_0_IRQHandler (void) __attribute__ ((weak, alias("Default_Handler")));
void VADC0_C0_1_IRQHandler (void) __attribute__ ((weak, alias("Default_Handler")));
void VADC0_C0_2_IRQHandler (void) __attribute__ ((weak, alias("Default_Handler")));
void VADC0_C0_3_IRQHandler (void) __attribute__ ((weak, alias("Default_Handler")));

Copy the list of names with the empty handlers to the __VECTOR_TABLE_ATTRIBUTE separated by commas (around line 99 in the template). Starting from the same assembly exception list as in the previous point, this translates to:

    

        
        
extern const VECTOR_TABLE_Type __VECTOR_TABLE[240];
       const VECTOR_TABLE_Type __VECTOR_TABLE[240] __VECTOR_TABLE_ATTRIBUTE = {
  (VECTOR_TABLE_Type)(&__INITIAL_SP),       /*     Initial Stack Pointer */
  Reset_Handler,                            /*     Reset Handler */
  NMI_Handler,                              /* -14 NMI Handler */
  HardFault_Handler,                        /* -13 Hard Fault Handler */
  MemManage_Handler,                        /* -12 MPU Fault Handler */
  BusFault_Handler,                         /* -11 Bus Fault Handler */
  UsageFault_Handler,                       /* -10 Usage Fault Handler */
  0,                                        /*     Reserved */
  0,                                        /*     Reserved */
  0,                                        /*     Reserved */
  0,                                        /*     Reserved */
  SVC_Handler,                              /*  -5 SVC Handler */
  DebugMon_Handler,                         /*  -4 Debug Monitor Handler */
  0,                                        /*     Reserved */
  PendSV_Handler,                           /*  -2 PendSV Handler */
  SysTick_Handler,                          /*  -1 SysTick Handler */

  /* Interrupts */
  SCU_0_IRQHandler,
  ERU0_0_IRQHandler,
  ERU0_1_IRQHandler,
  ERU0_2_IRQHandler,
  ERU0_3_IRQHandler,
  ERU1_0_IRQHandler,
  ERU1_1_IRQHandler,
  ERU1_2_IRQHandler,
  ERU1_3_IRQHandler,
  0,
  0,
  0,
  PMU0_0_IRQHandler,
  0,
  VADC0_C0_0_IRQHandler,
  VADC0_C0_1_IRQHandler,
  VADC0_C0_2_IRQHandler,
  VADC0_C0_3_IRQHandler
  /* Further interrupts are left out */
};

Make sure that additional functions (boot code, for example) are implemented in C.

If you have conditional assembly, replace it with conditional compilation:

Code Example

    

        
        
IF (USE_CHIP=SOME_CHIP)
  DCD  WDT_IRQHandler
ELSE
  DCD  _RESERVED
ENDIF

Translates to:

    

        
        
#if (USE_CHIP=SOME_CHIP)
WDT_IRQHandler,
#else
0,
#endif

Save your new startup_device.c file. If you have entries for stack and heap size in the assembly startup file, save these and add them in the next step to the now mandatory scatter file.

Scatter file creation

Copy the scatter file template from the CMSIS-DFP repo into your device support repo. The scatter file template for the Cortex-M4 is called ARMCM4_ac6.sct .
Edit the template according to your device settings. These values need to be set:

    

        
        
#define __ROM_BASE      0x00000000
#define __ROM_SIZE      0x00080000

#define __RAM_BASE      0x20000000
#define __RAM_SIZE      0x00040000

#define __STACK_SIZE    0x00000200
#define __HEAP_SIZE     0x00000C00

CMSIS-Pack update

Make the necessary changes to your PDSC file. Replace the startup_device.s file with the new startup_device.c file and add the device’s scatter file as follows:

    

        
        
          <!-- startup / system / scatter files -->
          <file category="sourceC"      name="path/to/startup_device.c"      version="1.0.1" attr="config"/>
          <file category="linkerScript" name="path/to/device_ac6.sct" version="1.0.0" attr="config" condition="ARMCC6"/>

Finally, create a new pack with the updated device support so that you can migrate the projects to Arm Compiler 6.

Back

Migrating CMSIS-Packs to CMSIS v6

Introduction

Device support

Example projects

Next Steps

Migrating CMSIS-Packs to CMSIS v6

Supported toolchains

Update the device support

Create C-based startup code

Scatter file creation

CMSIS-Pack update