Bernd,
The boot re-entry address is 0x20B00008. The following lines of code will need to be added to your files:
_romtBootReentry_addr=0x20B00008; //Should be added to the top of your *.cmd file
extern unsigned int romtBootReentry_addr; //Should be added to the top of your *.c file
void (*fcn)(void); //Should be added in a function in your *.c file to create the fcn pointer
fcn = (void (*)(void))&romtBootReentry_addr; //Add to the same function where the fcn pointer was declared
(*fcn)(); //Add just below the previous line, this is where you actually branch to boot re-entry.
The output from the hex6x utility means that those sections didn't fit in the area that you specified in your *.rmd file that you provided to the hex6x utility. The *.rmd file should give an origin address as well as a length that will cover the entire size of the sections that you are trying to convert to hex.
Thanks,
Jason Reeder