Why data can not be alloced in specified flash area? - MC9S12XEQ512

[MicroTang]

Hi All,

The MCU is MC9S12XEQ512.

In PRM file,  a flash area CONFIG_AREA defined and user segment USER_CONFIG_SECTION is placed into the segment.

SEGMENTS

...

CONFIG_AREA = READ_ONLY   0xFE8000 TO 0xFE83FF;  /* Configuration Area: 1024 bytes*/

...

END

PLACEMENT

...

USER_CONFIG_SECTION INTO CONFIG_AREA;

...

END

Added p/n to subject.

In source code

#pragma CONST_SEG __GPAGE_SEG USER_CONFIG_SECTION

const T_uConfigHeader CFG_Header = {
    (T_u16)0x00u,      

    (T_u16)123u,  
    (T_u32)0x01020304u, 
    (T_u16)0x00u

};

const FileID_STRUCT CFG_BeginFileID = {
    (T_u8) BNG_FILEID_BYTE0_VALID, 
    (T_u8) BNG_FILEID_BYTE1_VALID, 

    (T_u8) BNG_FILEID_BYTE2_VALID, 
    (T_u8) BNG_FILEID_BYTE3_VALID, 

    (T_u8) BNG_FILEID_BYTE4_VALID, 
}; 

const T_uCFGRecord CFG_Records[CFM_GCC_MAXNOOFRECORDS] = {
    {
        (T_u8)0x11u, (T_u8)0x00u, (T_u16)0x0014u,(T_u8)0x00u, (T_u8)0x10u, (T_u8)0x00u, (T_u8)0x03u, (T_u8)0x00u, (T_u8)0x00u
    },
    {
        (T_u8)0x20u, (T_u8)0x00u, (T_u16)0xC000u,(T_u8)0x10u, (T_u8)0x1Fu, (T_u8)0x11u, (T_u8)0x12u, (T_u8)0x13u, (T_u8)0x14u
    },   
    {
        (T_u8)0x20u, (T_u8)0x00u, (T_u16)0xC001u,(T_u8)0x12u, (T_u8)0x2Fu, (T_u8)0x21u, (T_u8)0x22u, (T_u8)0x23u, (T_u8)0x24u
    }

}

...

But when I complied the code and checked map file, only CFG_Header and CFG_Records put in USER_CONFIG_SECTION, and CFG_BeginFileID is lost! 

SECTION: "USER_CONFIG_SECTION"
  CFG_Header CFG_Records

usr_cfg.obj:
  CFG_BeginFileID

Could you please tell me why CFG_BeginFileID can not alloced in USER_CONFIG_SECTION?

Thanks!

Message Edited by NLFSJ on 2008-12-16 09:49 PM

[Steve]

Do you refer to CFG_BeginFileID anywhere in the code? It sounds like CodeWarrior is optimising out the array because it is not used.

[MicroTang]

Hi Steve,

Thanks for your information.

Yes, CFG_BeginFileID has not been referred. There is a function in other module read it's value by 'external'. Are there any #pragma options or complier options can keep CFG_BeginFileID in USER_CONFIG_SECTION?

[CrasyCat]

Hello

Can you please check the .map file generated by the linker.

Is the table CFG_BeginFileID allocated in another section or is it enumerated in the

UNUSED-OBJECTS SECTION?

When you declared the table CFG_BeginFileID  as external did you specify it is located in section USER_CONFIG_SECTION?

You need to specify the pragma CONST_SEG in the variable declaration as well.

CrasyCat

[MicroTang · Accepted solution]

Hi All,

The problem has been resolved.

Add

ENTRIES

usr_cfg.obj: CFG_BeginFileID

END

into prm file. The CFG_BeginFileID is alloced in USER_CONFIG_SECTION.

Thank you very much!

[CompilerGuru]

Why do you want to link CFG_BeginFileID even if it is not referenced?