Nikon Firmware Insights #05

Just to let people know, yes I’ve been working on understanding the D5100 firmware.

I’ve got most the area’s of code identified (where they are, not what they do), but there are some puzzles, with some chunks of code that are used (eg selects a picture to be shown based on shooting mode) but the code it self is not directly linked to, and it’s address in not present in the image. There is defiantly some form of jump/call table compression/encoding done, as there are functions that do some maths, and then call the result. So that needs to be puzzled out.

So to help map the data (and thus remove possible options from above puzzle), I previous mentioned mapping the jpg’s out:

As can be seen in this small sample, there’s the icons for the different shooting modes, and three colour schemes.

Last night I was working on using a modified version of BinViz (original found here) and have found how the font’s and overlay text/images are packed, and I am in the process of tracking down how the width/size information is encoded in the associated data tables. Shown below is the same block of data shown, but at two different widths, showing the “Dial” overlays and the “Bulb Time” text:

It’s quite neat looking at the Asian font sets, as the fonts/overlays use subpixel rendering, which can be seen in the green arm of the sports mode dial icon above. Much simpler, the normal overlays are just black/white, and now look better X/Y scaled.

I started a Google Code Project called Nikon Firmware Tools in which I’m placing the tools I’m using and the changes I’m making to them as I go. So interested developers can look there. Sorry only code so far.


Interested in more, come join the us at Nikon Hacker, or use the Online Patch Tool (Help)