How to dump tiles from a GameBoy ROM on Linux

published: 2020-04-08

Download the yy-chr tool. Extract it to a directory of your choice.

Please note that it comes as a Windows binary; from my personal tests, it runs quite well in WINE.

Open/run yychr.exe. Go to File > Open and open the ROM you want to dump tiles from.
Scroll to the place in the ROM you want to dump files from.
Go to File > Save snapshot. It will ask you to save a file named chrXXX.bmp, where XXX is a number. Save it wherever you please.
Repeat steps 3 and 4 until you have saved screenshots of all the places in the ROM that have tiles you want to dump.
Once you are done, open a terminal and cd to the directory you saved the BMP files as.
Run the following command, replacing XXX with the actual numbers in the file name:

convert chrXXX.bmp -crop 16x16@ +repage +adjoin tile-%d.bmp

This will dump each individual 8x8 tile into its own separate BMP file. Please be warned: this may generate more than a hundred files in that folder! Best to keep each separate chrXXX.bmp file in its own folder to keep everything organized.