Firmware RE (Beginner)

I’m trying to learn RE, and I thought I’d look at some firmware that interests me. I’m looking at the Roland TD-11 drum module firmware, which is available for download from the Roland website

I found a few guides to get me started, and most seem to recommend binwalk. Unfortunately, binwalk doesn’t seem to return anything when I run it against the firmware file. I ran the entropy analysis, and from what I’ve been reading, the firmware doesn’t seem to be encrypted.

Running strings, I can find strings in the firmware image as well. And binwalk -Y returned:

1189309       0x1225BD        ARM executable code, 16-bit (Thumb), little endian, at least 779 valid instructions

I’m also looking at Ghidra, but I’m not sure where to start. Should I try to unravel some of the instructions in Ghidra? I don’t think Ghidra is identifying the functions properly. Is there a way to identify the entry point of the firmware program? What are some avenues I should explore to get a starting point in analyzing this firmware?