AVR C: Int to hexadecimal address

Question

Working with AVR GCC on an Atmega1284P, I used to have the following:

#define CMP_START_ADDR 0x18000
static UInt32 loadingAddr = CMP_START_ADDR;
static UInt32 newCmpAddr = CMP_START_ADDR;

Where, eg loadingAddr , is used as follows somewhere (as an address):

        boot_program_page(loadingAddr,block_page);

and where UInt32 is typedef unsigned long UInt32;

Now I want the same setup but as follows:

#define CMP_START_ADDR ROM_SIZE-RESERVED_CMP_ROM_SPACE

static UInt8 amount_of_files = 0;
static UInt32 loadingAddr = CMP_START_ADDR;
static UInt32 newCmpAddr = CMP_START_ADDR;

Where ROM_SIZE and RESERVED_CMP_ROM_SPACE are respectively defined somewhere as:

    #define ROM_SIZE            FLASHEND
    #define RESERVED_CMP_ROM_SPACE  28000

And FLASHEND is from iom128.h:

#define FLASHEND   0x1FFFF

The new code compiles but does not work. I assume the address goes wrong because I'm using integers and hexadecimals inconsistently. How would I most efficiently resolve this?

Answer 1

RESERVED_CMP_ROM_SPACE  28000

28000 is not page aligned so if your implementation of boot_program_page is the one here the program will compile and even do something but not write the program you expect. If you read the memory with a debugger after bootload I think you will observe something like a3a1a2b3b1b2c3c1c2 instead of a1a2a3b1b2b3c1c2c3.

Try with RESERVED_CMP_ROM_SPACE 32768