topic Re: Compiler error: Pointer to a __far location in CodeWarrior for MCU

Compiler error: Pointer to a __far location

sep2kor — Thu, 16 Dec 2010 15:30:21 GMT

Hi,

I have written a small piece of code to copy the contents of paged flash memory into Ram.

const __far MemSegTable BL_AddressTable =
{
     { 0x00005000uL, 0x00006BFFuL },
     { 0x0000C000uL, 0x0000CFFFuL },
     { 0x00E08000uL, 0x00E0BFFFuL },
     { 0x00E18000uL, 0x00E1BFFFuL },
     { 0x00E28000uL, 0x00E2BFFFuL },
     { 0x00E38000uL, 0x00E3BFFFuL }
};

const __far uint32 BL_PtrToArray[6] =
{
    0xD18000,   /* Address of BL_Array_D1 */
    0xD28000,   /* Address of BL_Array_D2 */
    0xD38000,   /* Address of BL_Array_D3 */
    0xD48000,   /* Address of BL_Array_D4 */
    0xD58000,   /* Address of BL_Array_D5 */
    0xD68000    /* Address of BL_Array_D6 */
};

function( )

{

             flashAddress_t                 StartAddress;
             flashMemoryLength_t     PageLength;
             uint32                                 count;
             uint8 const __far *           pBootloaderArray;
             uint8 *                                 pRAMBuffer;

                         StartAddress          = BL_AddressTable[NumOfBlks][0];
                         PageLength          = ( BL_AddressTable[NumOfBlks][1] - BL_AddressTable[NumOfBlks][0] + 1 );
                         pBootloaderArray = ( uint8 const __far * )((const __far uint32)BL_PtrToArray[NumOfBlks]);
                         pRAMBuffer            = RAMBuffer;
                         count                       = 0x100;

                         while (count)
                         {
                                         ( * ( ( uint8 * ) pRAMBuffer ) ) = ( * ( ( uint8 const __far * ) ( pBootloaderArray ) ) );
                                         ( ( uint8 const __far *) ( pBootloaderArray ) )++;
                                         ( ( uint8 * ) pRAMBuffer )++;
                                         count--;
                         }

return();

}

I am getting the following error:

C1069: Wrong use of far/near/rom/uni/paged in local scope

Can anybody help me?

Re: Compiler error: Pointer to a __far location

sep2kor — Thu, 16 Dec 2010 15:37:46 GMT

Sorry, the code is as written below.

uint8 RAMBuffer[0x100];

const __far uint32 BL_PtrToArray[6] =
{
    0xD18000,   /* Address of BL_Array_D1 */
    0xD28000,   /* Address of BL_Array_D2 */
    0xD38000,   /* Address of BL_Array_D3 */
    0xD48000,   /* Address of BL_Array_D4 */
    0xD58000,   /* Address of BL_Array_D5 */
    0xD68000    /* Address of BL_Array_D6 */
};

function( )

{

             uint32                                 count;
             uint8 const __far *           pBootloaderArray;
             uint8 *                                 pRAMBuffer;

                         pBootloaderArray = ( uint8 const __far * )((const __far uint32)BL_PtrToArray[NumOfBlks]);
                         pRAMBuffer            = RAMBuffer;
                         count                       = 0x100;

return();

}

The error is on lines -

"uint8 const __far * pBootloaderArray;"

"pBootloaderArray = ( uint8 const __far * )((const __far uint32)BL_PtrToArray[NumOfBlks]);"

" ( * ( ( uint8 * ) pRAMBuffer ) ) = ( * ( ( uint8 const __far * ) ( pBootloaderArray ) ) ); "

Note: The aarray BL_PtrToArray[ ] is located in paged memory. The array RAMBuffer[ ] is in unpaged memeory.

Can anybody help me?

Re: Compiler error: Pointer to a __far location

CrasyCat — Thu, 29 Oct 2020 09:18:43 GMT

Hello

I would not recommend using far qualifier for anything else than a function or a pointer.

If you want to tell the compiler an object is allocated in paged memory you need to define it as follows:

#pragma CONST_SEG __GPAGE_SEG myPAGED_CONST
const __far uint32 BL_PtrToArray[6] =
{
    0xD18000,   /* Address of BL_Array_D1 */
    0xD28000,   /* Address of BL_Array_D2 */
    0xD38000,   /* Address of BL_Array_D3 */
    0xD48000,   /* Address of BL_Array_D4 */
    0xD58000,   /* Address of BL_Array_D5 */
    0xD68000    /* Address of BL_Array_D6 */
};

#pragma CONST_SEG DEFAULT

Also I would modify the initialization of pBootloadArray as follows:

pBootloaderArray = ( uint8 const __far * )(BL_PtrToArray[NumOfBlks]);

Please refer to TN238.pdf in {Install}\Help\PDF for more information on how to define variable, constants in paged memory.

CrasyCat

Re: Compiler error: Pointer to a __far location

sep2kor — Thu, 16 Dec 2010 19:50:37 GMT

Thanks CrasyCat