Beginner doing something stupid

Help on how to use HxD.
Post Reply
donrecardo
Posts: 2
Joined: 01 Apr 2014 15:10

Beginner doing something stupid

Post by donrecardo »

I am sure there is an easy answer to this but being a beginner I dont know what it is

I have a small dev board from Sure Electronics with a pic 18F4520 on it
On powering up it says " Sure Electronics V1.1 " on the LCD

I have a copy of the firmware that is loaded into it and I know that it works because I loaded it in many times
My plan was to load the firmware hex file into an editor and change the displayed text to something of my choosing


I have two text editors , " Neo" and HxD
I did Open File and chose the firmware with Neo but the line I wanted to change didn't appear anywhere in the text window ,
but Neo also has several other open options like open proccess and open Hex. I chose the option to , Open Hex and when I did ,
sure enough I found the line I want to change , it starts at 0000165a
I changed it ( keeping the same amount of characters) , saved it , but when I tried to load it back into the editor it told me it was corrupt.

That was when I downloaded HxD , Thinking I might have more luck, but when I load the file in there , The line I want is nowhere to be seen .
at 0000165a it should start with 53 75 72 65 which are the hex codes for ' Sure ' but instead it says 39 32 38 30 which doesn't make much sense to me

Can someone please tell me how , using HxD do I load in my hex firmware and get it to display the text in a readable manner ,
and then is there any special way to save it , after altering the text , so that the file is not corrupt ?
Maël
Site Admin
Posts: 1455
Joined: 12 Mar 2005 14:15

Re: Beginner doing something stupid

Post by Maël »

It's hard to reply to that without seeing what file you have and what you want to do.
But I can give you a general answer.

HxD is a hex editor, not a text editor. The right column is showing the interpretation of the data as text. Sometimes it makes sense, sometimes not.

If you want to edit a firmware hex file you don't need to open processes or the RAM editor. The RAM editor is just for viewing running programs (=processes) on your current PC (where HxD runs), so this has nothing to do with your electronics board.

What you need to find out is the encoding of this firmware hex file. Maybe it has some checksum, so that changing the contents of that file will make the checksum invalid.

Try to find out the encoding/file format of this file, and see if someone on the forums for that electronics board can help you more.
donrecardo
Posts: 2
Joined: 01 Apr 2014 15:10

Re: Beginner doing something stupid

Post by donrecardo »

Thank you for your reply

I will try asking Sure Electronics that made the board

Regards
Don
Post Reply