hexdump -s 0x550 -C optiboot_atmega328.hex
:
What am I missing?
The .hex file is already an ascii-ized file of hex characters, so if you use "hexdump", you are dumping the ascii data rather than the binary content represented by the .hex file. You either want "avr-objdump" or "tail":
tail -3l optiboot_atmega328.hex
:027FFE00[color=red]0206[/color]79
:0400000300007E007B
:00000001FF
> avr-objdump -march=avr -s optiboot_atmega328.hex
optiboot_atmega328.hex: file format ihex
Contents of section .sec1:
7e00 1f92cdb7 deb71124 84b714be 982f9d70 .......$...../.p
:
7fc0 f1cf282e 80e0e8df e0e0ff27 0994 ..(........'..
Contents of section .sec2:
7ffe [color=red]0206[/color] ..