MIDI daemon for OPL3-FPGA using PetaLinux

This allows Greg Taylor's OPL3-FPGA to be controlled from a PC using USB-MIDI. The main purpose is to allow the use of OPL3-FPGA with modified versions of ScummVM and DOSBox through a USB connection.

News

2018-1-8

This project has been updated for Vivado/PetaLinux 2017.4.
Pre-built SD card image files are in the "images" folder. Feel free to copy these to a MicroSD card and skip to the "Running" section of the README.

Building

Install Vivado 2017.4 and PetaLinux 2017.4.

Set up the environment:

 source /path/to/vivado/settings64.sh
 source /path/to/petalinux/settings.sh

Download Greg Taylor's OPL3_FPGA BSP

Create a new PetaLinux project:

 petalinux-create -t project -s ZYBO_OPL3_FPGA_2017_4.bsp

Create two new Petalinux apps. From the <project_folder>:

 petalinux-create -t apps --template c --name opl3d --enable
 petalinux-create -t apps --template install --name midi --enable

Clone the Vivado/PetaLinux-2017.4 branch of this git repository and replace the "midi" and "opl3d" folders in:
```
 <project-folder>/project-spec/meta-user/recipes-apps
```

with the "midi" and "opl3d" folders from the repository.

Edit /project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi and add the following:

 /{
     usb_phy0: usb_phy@0 {
     compatible = "usb-nop-xceiv";
     #phy-cells = <0>;
     };
 };
 
 &usb0 {
     dr_mode = "otg";
     usb-phy = <&usb_phy0>;
 };

Configure the kernel:
```
 petalinux-config -c kernel
```

Enable the following options:

Device Drivers > USB support > USB Gadget Support -> MIDI function (*)

Then exit and save the configuration

Configure the apps:
```
 petalinux-config -c rootfs
```

Enable the following options:

Apps > midi (*)
Apps > opl3d (*)

Then exit and save the configuration

Build Linux:
```
 petalinux-build
```

Use petalinux-package to generate BOOT.BIN:

petalinux-package --boot --fsbl images/linux/zynq_fsbl.elf --fpga images/linux/opl3.bit --u-boot

Running

Copy BOOT.BIN and image.ub (from images/linux) onto a MicroSD card and insert it into the ZYBO
Set JP5 to SD to enable booting from the MicroSD card
Remove JP1 to enable OTG mode
Use a Micro-USB cable to connect J9 (on the bottom side of the ZYBO!) to your PC.
Power on the ZYBO

Use with ScummVM

Clone https://github.com/waltervn/scummvm.git and build the 'opl3-fpga' branch.
In the ScummVM launcher, go to Options > Audio and select "OPL3 FPGA" in the Adlib emulator list box. Click OK to save. Any games set up for AdLib will now use OPL3-FPGA.

Use with DOSBox

Clone https://github.com/waltervn/dosbox.git and build the 'opl3-fpga' branch.
Edit dosbox.conf and make the following changes: