Re: [avr-gcc-list] Format of HEX file when program memory addresses exceed 64K

[Mark Litwack]

On Thu, 06 May 2010 14:34:34 -0400
"Graham Davies" <address@hidden> wrote:
> [...]
> What I need to know is what the HEX file is going to look
> like when my program inevitably grows is size above
> 64Kbytes.  What mechanism will 'objcopy' use to get above
> sixteen address bits?  I need to know this exactly
> because I need to write a Flash loader to read such a
> file.
> 
> I just need to know where to look for this information or
> what to Google for.

Hi Graham,

Look here for info on the format:

  http://en.wikipedia.org/wiki/Intel_HEX

avr-objcopy uses record type 02 to get beyond 64k.  Here is
an example of what it outputs at the boundary:

  ...
  :10FFD000AA19BB09A330B10570F4C50162E0A601FE
  :10FFE0000E9451D88B81882309F04EC2C8010E941B
  :10FFF00005380C948D52159798F4C50164E0AE0154
  :020000021000EC
  :100000004D5F5F4F0E9451D89B01AC018B818823CB
  :1000100009F03AC2C801B9010E94C2390C948D524C
  :10002000C50168E0AE014D5F5F4F0E9451D8AB0142
  ...

If you're writing something to interpret the hex format, you
might also want to be able to deal with type 04 which is
another mechanism that can be used for >64k.

-mark