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

1. Install Vivado 2017.4 and PetaLinux 2017.4.

2. Set up the environment:

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

3. Download Greg Taylor's OPL3_FPGA BSP

4. Create a new PetaLinux project:

    petalinux-create -t project -s ZYBO_OPL3_FPGA_2017_4.bsp
   

5. 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
   

6. 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.

6. 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>;
    };
   

7. 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

8. Configure the apps:

    petalinux-config -c rootfs
   

Enable the following options:

• Apps > midi (*)
• Apps > opl3d (*)

Then exit and save the configuration

9. Build Linux:

    petalinux-build
   

10. Use petalinux-package to generate BOOT.BIN:

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

Running

1. Copy BOOT.BIN and image.ub (from images/linux) onto a MicroSD card and insert it into the ZYBO

2. Set JP5 to SD to enable booting from the MicroSD card

3. Remove JP1 to enable OTG mode

4. Use a Micro-USB cable to connect J9 (on the bottom side of the ZYBO!) to your PC.

5. Power on the ZYBO

Use with ScummVM

1. Clone https://github.com/waltervn/scummvm.git and build the 'opl3-fpga' branch.

2. 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

1. Clone https://github.com/waltervn/dosbox.git and build the 'opl3-fpga' branch.

2. Edit dosbox.conf and make the following changes:

• Under [sblaster] set oplmode to 'opl3fpga'.

• Under [midi] set midiconfig to point to the OPL3-FPGA midi device.

  For Linux, try the following: Run 'aconnect -l' and look for "MIDI function". Use the client number you see there to set 'midiconfig'. E.g. if your client number is 28, set midiconfig to "28:0".

  Other operating systems should work as well, as long as DOSBox has MIDI support for that platform, and you can point DOSBox to the OPL3-FPGA.