AVR Freaks

Will the flash always be the .text + .data ?  There are quite a number of sections in the ELF!

Hi Everyone,

I'm attaching the tool I made (crc16tool.exe) as well as its source code in C.  Also attached is an example which shows the AVR side code for flash 64K and less (easily modified to support >64K).  The tool was written to handle up to 1M of flash, but not tested above 8k so far.  Multiple filenames can be put on the command line and it will process all of them.  It can process ELF and HEX files.  It is finished, but I wouldn't say optimized or polished.

Upsides over the "srec_cat put the crc at the end method" are that this does not expand the programming size to the full size of the device, but yet does check the full size of the flash.  It also works with ELF files as well as HEX files.

One of the reason I did this was so I could produce a single ELF with fuse bits, lock bits, and the crc16 embedded correctly in it, so I could have a single file to flash in one operation.  I can also now keep my fuse/lockbit settings in my main.c and out of a batch file.

I will eventually add it as a project here, once I get some documentation made for it.

>crc16tool test.elf test.hex
CRC16TOOL 1.00

Processing test.elf
  File is ELF.
  Size is 7824 bytes.
  Scanning for cRcL signature.
  Found at 0x000000E6, Flash Size 32768 bytes.
  Calculating CRC16.
  CRC16 is 0x9B87
  Updating file.

Processing test.hex
  File is HEX.
  Loading file into memory.
  Size is 7824 bytes.
  Scanning for cRcL signature.
  Found at 0x000000E6, Flash Size 32768 bytes.
  Calculating CRC16.
  CRC16 is 0x9B87
  Updating file.

example.c

//sets the flash size 032=32Kb (must be 9 chars long with xx on end, do not remove xx)
//must be outside of function for PROGMEM to work properly
const char MsgCRC[] PROGMEM = "cRcL032xx";

int main()
  {

    //code to check crc16 (<64kb)
    {
      uint16_t crc_ui1,crc_ui2,crc_ui3;

      crc_ui2=((pgm_read_byte(MsgCRC+5)-'0')*10+(pgm_read_byte(MsgCRC+6)-'0'))*1024;
      crc_ui3=0xffff;
      for (crc_ui1=0;crc_ui1<crc_ui2;crc_ui1++)
        if (crc_ui1==MsgCRC+7 || crc_ui1==MsgCRC+8)
          crc_ui3=_crc16_update(crc_ui3,'x');
        else crc_ui3=_crc16_update(crc_ui3,pgm_read_byte(crc_ui1));
      crc_ui3=~crc_ui3;
      if (crc_ui3!=pgm_read_word(MsgCRC+7))
        {
          //crc failure

          //debug indicate failure here

          for(;;);
        }
    }

  }

You can easily put a post build command to call it from AS6:

c:\path\crc16tool "$(MSBuildProjectDirectory)\$(Configuration)\$(OutputFileName).hex" "$(MSBuildProjectDirectory)\$(Configuration)\$(OutputFileName).elf"

Tool updated to 1.01, it could not handle a 0 byte .text or .data segment, but now it can.

Hi Jerry,

I see what you mean.  I hope my tool/method is easier as you just pass it the ELF or HEX and it calculates the crc16 and updates it.  Beyond that you just have the AVR side code which checks it. 

Does anyone have an ELF with a bootloader and application present?  I am just loading the .text followed by the .data sections starting at 0x0000 right now in the ELF processor.

Thanks,

Alan

Hi Jerry,

It should return 0 for ok.

It will return 1 for any of these conditions:

unable to allocate memory

unable to open file

unable to read from file

signature not found

too many signatures found

unable to seek file

file is corrupt

extended address to large

unknown record type in hex file

unable to write

unknown file type

It will print this error to the console and you should see it in the compiler messages.  Do you see an error surrounding the call?

I use this in the studio post build area:

"c:\crc16 tool\crc16tool" "$(MSBuildProjectDirectory)\$(Configuration)\$(OutputFileName).hex" "$(MSBuildProjectDirectory)\$(Configuration)\$(OutputFileName).elf"

Thanks,

Alan