Optional device patches (tools/mpc_patch)

Machinedrum Module / Machinemodule, 6W6, 8W8, CW-78, 9W9, TR-MPC and Lucky Dip get MPC's drum layout with all 16 pads lit. On Gen2 (Live III) it runs a patched copy of MPC instead of changing the system.

None of these is part of any plugin release. Each is a standalone script you run on the device yourself, if you want it. They change the device, not just add files, so each has its own warnings, backups and uninstall.

Ways to install

All three scripts share one interface (status, install, uninstall, and --confirmed to skip the typed question), so both routes run the same code.

1. The installer app, "Advanced: device patches" step (docs/PATCHES.md). It lists the patches from catalog/patches.json, shows status for each (applied / not applied / unsupported firmware), and runs install / uninstall after you type the confirmation word. It downloads the script, checks its sha256 and passes --confirmed itself. Apply and Undo from the app are built and tested offline only (not yet on a device); the step is otherwise read-only. The same patches are on the catalog page's Device patches tab, with a guide page each.
2. By hand over SSH (always available): copy the script to the device and run it as root; see "Use" below and each patch's README.

Every patch is opt-in: nothing applies by default, as part of a plugin install, or as part of an update. Save your project first (the drum-pad and hwremap patches restart MPC).

16-pad drum layout (mpc-drum-pad-patch.sh)

What it does

Stock MPC OS 3.9.1.2 treats only Akai's own DrumSynth:Multi as a drum instrument. The patch makes MPC treat the plugins in its name table (Machinedrum Module / Machinemodule, 6W6, 8W8, CW-78, 9W9, TR-MPC, Lucky Dip) as drum instruments with 16 pads, all lit; pad n sends MIDI note n-1, which these plugins accept. Akai's DrumSynth Multi keeps its layout but also shows 16 lit pads. The pad colour is one red for every plugin. You can edit the pad colours with the standard Pad Colour Editor like normal manually.

Gen2 (MPC Live III and kin, aarch64)

The same script handles Gen2, chosen by uname -m. The root filesystem there is read-only (dm-verity), so /usr/bin/MPC is not changed. install copies the MPC this system runs (the root's 3.9.1, or the 3.10.0 kit that a drop-in binds over it) to /data/mpc-drumpad/MPC, applies the patch to the copy, checks its checksum, and writes /run/systemd/system/acvs.service.d/94-mpc-drumpad.conf (BindReadOnlyPaths= the copy over /usr/bin/MPC), then restarts MPC. The drop-in is named 94- on purpose: systemd keeps the first bind of a path, so it has to sort before the 3.10 kit's 95-mpc310.conf.

• Supported: stock Gen2 MPC OS 3.9.1 (a7ace6a9993df33afeae50571755bbf9) and 3.10.0 (15a664f6b6ae591c8b78baae8b376f02); anything else is refused.
• /run is cleared by a reboot, so MPC is stock again after one. sh mpc-drum-pad-patch.sh reapply puts the drop-in back (--restart also restarts MPC); the mpc310-on-391 stick calls it at boot (install leaves a copy of the script in /data/mpc-drumpad for that). uninstall removes the copy and the drop-in and restarts MPC. No 112 MB backup is needed: the system's own MPC is never written.
• Same patch as the Force (name table, six 8 to 16 pad counts, 16-pad colour loop) at aarch64 addresses; sources and tests in gen2/ (make_patch_gen2.py, test_gen2_emu.py under Unicorn, and test_script_gen2.sh for the script in BusyBox).

Gen1 (MPC Live / One / X / Key, armv7), MPC OS 3.10.0

Same in-place method as the Force (armv7, writable root, backup to /sdcard/MPC-backup); the script picks the build by the checksum of /usr/bin/MPC. Supported: stock Gen1 3.10.0 (b6cc8e7a398bdf6c3fd8f7176eecd3ee). The three changes sit at the Force patch's code shapes, found by matching; sources and tests in gen1/ (make_patch_gen1.py, test_gen1_emu.py under Unicorn, test_script_gen1.sh in BusyBox). Not tried on a Gen1 device yet. Gen1 3.9.1 is not covered: its MPC is UPX-packed, so there are no fixed bytes to patch.

Read this first

• It modifies Akai's factory MPC program (/usr/bin/MPC). Use it at your own risk; it is not an Akai product.
• It works only on the Force's MPC OS 3.9.1.2, Gen1 MPC OS 3.10.0, and Gen2 MPC OS 3.9.1 and 3.10.0 (both checked by the exact checksum); it refuses anything else. A firmware update replaces the file and removes the patch; run the script again afterwards (it refuses until this project supports the new build).
• Installing stops and restarts MPC: save your project first.
• You need root SSH access to the device. The script only runs on the device.
• Nothing of Akai's is in the script: only the changed bytes and checksums.

Use

By hand, copy it to the device and run it as root (or use the installer app, above):

scp tools/mpc_patch/mpc-drum-pad-patch.sh root@<device-ip>:/tmp/
ssh root@<device-ip>
sh /tmp/mpc-drum-pad-patch.sh status      # changes nothing
sh /tmp/mpc-drum-pad-patch.sh install     # shows the warnings, asks you to type PATCH
sh /tmp/mpc-drum-pad-patch.sh uninstall   # puts the original bytes back

For programs (the installer app's patches step, docs/PATCHES.md): status ends with one line STATE state=stock|patched|old-patch|unsupported supported=0|1 backup=0|1, and install --confirmed skips the typed question (the caller has shown the warnings and asked for the word itself). Everything else is unchanged; other firmware is refused either way. install saves the full original MPC (112 MB) and the original bytes to /sdcard/MPC-backup first, checks the result by checksum, and restores the original itself if that fails. A device that has the earlier Machinedrum-only patch is upgraded (the old patch is undone first).

If status says your MPC is a build this script does not know

status prints the checksum of /usr/bin/MPC. Stock 3.9.1.2 and the builds this script made are recognised; anything else (another firmware, or an earlier development version of this patch) is refused by install, and the page in the installer app shows the checksum as the reason.

If an earlier install saved a full backup (/sdcard/MPC-backup/MPC-3.9.1.2.orig), uninstall can put the stock program back from it even then. It first checks that the backup's checksum is the stock one (592eebc8e1ce0797dc8c98e7002143b8) and refuses otherwise, asks you to type RESTORE (or takes --confirmed), copies the backup over /usr/bin/MPC, checks the result and restarts MPC: save your project first. Afterwards install applies the current patch. Check the backup yourself first with md5sum /sdcard/MPC-backup/MPC-3.9.1.2.orig. If there is no backup, or it is not the stock program, nothing is touched; restore the factory MPC OS the way Akai documents.

Files (maintainers)

• matcher.S (plugin-name table, one .asciz line per plugin), cave2.S, helper.S, colours.S, colours_jump.S: the ARM sources. helper.S and colours*.S come from mpc-vst-machinedrum's release/mpc_patch (same author), unchanged; the name table and cave2.S are new.
• asm.sh assembles them in an arm32v7 gcc container; make_patch.py <stock MPC> writes mpc-3.9.1.2.patch (our bytes only) and checks the branch chain; build_script.py generates mpc-drum-pad-patch.sh from the template and the patch.
• Tests: test_matcher.sh runs the name matcher under qemu-user at its real address (6 names match, 12 others fall through to Akai's original check, r4 preserved). test_script.sh runs the script in BusyBox 1.36 (the Force's shell) against copies of the binary: install, cancelled install, repeated install, uninstall from either backup, upgrade from the old patch, refusing a refused upgrade and other firmware. All pass.
• Patched checksum f899e581cba179a831212083f9a55ae0; stock 592eebc8e1ce0797dc8c98e7002143b8.
• Adding a plugin: add its exact plugin name to the table in matcher.S, rebuild, re-run the tests. This folder is the one shared home: plugin repos link here instead of carrying a copy, so the patch is rebuilt in one place when the firmware changes.

All device patches