I desperately need help figuring out the ic chips in this unit so I can view the firmware in ida pro.
So the unit is a roland gr-55 guitar synthesizer and i'm trying to disassemble the firmware into assembly language, but I have no info on the processor type. I have tried to analyze the firmware, which is a binary file using binwalk but wasn't able to find any info. I've also used the tool cpu_rec to see if it would give me any info and it told me it's a pic10 but I don't thinks that's accurate. I'll post pics below of the gr-55 motherboard, and the firmware , and some other stuff.
gr-55 firmware link here's the roland gr-55's firmware
gr-55 schematics here's the roland gr-55 schematics
I think the R8A02021ABG could be the main cpu due to these forms (similar sythesizer internals). This person seems to have some of the same ic numbers, and hes saying the R8A02021ABG is the main processor, and that it's a sh3/sh4 7700 series processor. When I go to the link for his units OS website OS website for bk9 it tells me that the processor for that OS is a sh3 (sh 7727). It seems that ida pro does not have an option for a (sh 7727). I read another form from someone who said they also have a (sh 7727) in their unit, this website wont let me post any more links so if you type mpc500 os code in google and click link for mpc-forms.com, it's on the second page second comment down. This person says they don't make a disassembler for the (sh 7727) and reverse engineering it would be impossible
My main goal is to be able to change some things in the roland gr-55's firmware, like changing some of the names to make things easier to understand so I can make music in peace. Is what i'm trying to do even possible or am I just giving myself a headache for no reason. Sorry if the post is confusing, and for the excessive links. If anybody can give me any info I would appreciate it.