bin -> Intel HEX

$ srec_cat -Output foo.hex -Intel bar.bin -Binary -Output_Block_Size 16

$ objcopy -I binary -O ihex foo.bin bar.hex

ihex2txt - converts Intelhex format to a simple text format
txt2ihex - converts simple text format to Intelhex

       The  text  format is composed by a line with values separated with spaces.  The first value is the initial address,
       the following values are the values.
       Example: 02B7 07 B9 70 7A 6E
       means that the content of address 02B7 is 07, the content of address 02B8 is B9, the content of address 02B9 is 70,
       ...