POPSLoader

POPSLoader is a graphical PlayStation 2 homebrew launcher designed to easily browse and launch your PS1 games (using POPStarter) from various storage devices. It features a clean, responsive layout, cover art support, sound effects, an on-screen keyboard, and direct memory card exit shortcuts.

The current public release is BETA-11 (released 2026-06-15). Development continues on the BETA-12-PLAY branch; rolling test artifacts are published continuously (see Development & Building).

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Highlights

POPSLoader's stable backbone, hardware-confirmed across an extended validation pass:

• Fixed HDD POPSTARTER Handoff (D-10): Resolved the long-standing "D-10" black-screen hang when launching games using an HDD-backed POPStarter configuration. Hardware-confirmed.
• Fixed Cross-Device POPSTARTER (D-14 / D-15): HDD-backed POPSTARTER with non-HDD games and non-HDD POPSTARTER with HDD games both launch cleanly. Hardware-confirmed.
• DKWDRV from Memory Card and custom HDD path: Both launch routes work — the MC route via a reboot-IOP path with synthesized argv, the HDD custom path via a partition-aware route. Hardware-confirmed.
• BOOT.ELF Exit from POPSLoader: Returns to wLaunchELF / BOOT.ELF via the embedded-loader route, including the previously broken HDD-launched case (U-10). Hardware-confirmed.
• Single-device Settings parity: Every install — USB / MX4SIO / MMCE and the internal HDD — saves settings to .pldrs next to the launcher. HDD installs write it on the HDD's own boot partition (read-write mount take-over), no mc0: fallback (see Settings Storage on HDD Installs).
• In-app HDD game hiding, PAL full-screen, BDMA + MC-folder controls: The newer Settings work — see the Settings section below.
• Polished User Interface: Layout alignment corrections, cleaner typography, dynamic menu box adjustments, text wrapping, and notification toast hardening.

Note

The canonical, always-current Known Issues list and hardware-verification status live in STATE.md > Known Issues (with the full ledger in QA_REGRESSION_MATRIX.md). The current open item is the config-specific "Failed to load HDD" from a non-HDD boot; the 2026-06 HDD/PAL/BDMA features are implemented and boot on PCSX2 (HDD confirmed read-write on hardware by provato) and are still validating on hardware.

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Supported Devices

POPSLoader's main menu exposes the following backends:

• MMCE (Multi-Memory Card Emulator, e.g. MemoryCard PRO / SD2PSX)
• MX4SIO (SD card via memory card slot adapter)
• HDD (PFS) (internal HDD via the PS2 network/ATA adapter)
• USB (mass:)
• Disc (DKWDRV) (boot DKWDRV to play PS1 discs)

Note

The main menu also lists HDD (exFAT), i.Link, and SMB (v1), but these flows are not implemented yet — selecting them shows a "not implemented" notice. See Known Issues & Planned Improvements.

Note

Game compatibility and drive loading performance may vary depending on your specific console model, adapter type, and the quality of your POPStarter/POPS binaries.

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Quick Install

To set up POPSLoader:

1. Download the Release: Download and extract the latest POPSLOADER.zip package.
2. Copy Launcher Files: Copy the PS1_POPSLOADER/ folder to the device or memory card from which you want to launch POPSLoader.
3. Place POPS Files: Put the PATCH_5.BIN file (included in the POPS/ directory of the ZIP) into your active POPS folder (see directory structures below).
4. Add POPStarter & POPS Files: Add your POPStarter executable (POPSTARTER.ELF) and the required POPS support files (IOPRP252.IMG, POPS.ELF, POPS.PAK, POPS_IOX.PAK) to your POPS folder. These copyrighted Sony POPS files are not included in the release package.
5. Add Games: Copy your PS1 game images in .VCD format into the same POPS folder.
6. Launch: Run POPSLOADER.ELF using wLaunchELF, Free McBoot, or your preferred ELF launcher.

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Folder Layout

Ensure your directories and files match these paths exactly depending on your storage device:

USB / MX4SIO / MMCE Setup

Place all files on the root of your storage device (mass:/, mx4sio:/, mmce0:/, etc.) in a folder named POPS:

File Path	Description
<device>:/POPS/GameName.VCD	Your PS1 game image
<device>:/POPS/GameName.png	Optional cover art (200x200 8-bit PNG recommended)
<device>:/POPS/IOPRP252.IMG	Required POPS support file
<device>:/POPS/POPSTARTER.ELF	POPStarter launcher binary
<device>:/POPS/POPS.ELF	POPS emulator engine binary
<device>:/POPS/POPS.PAK	Emulator resources payload
<device>:/POPS/POPS_IOX.PAK	Emulator input/output resources payload

Internal HDD Setup

Place VCD game files inside your dedicated POPS partitions, and system binaries inside __common/POPS/:

File Path	Description
hdd:/__.POPS/GameName.VCD	Your PS1 game image (can also use partitions __.POPS0 through __.POPS9)
hdd:/__common/POPS/ART/GameName.png	Cover art folder
hdd:/__common/POPS/IOPRP252.IMG	Required POPS support file
hdd:/__common/POPS/POPS.ELF	POPS emulator engine binary
hdd:/__common/POPS/POPS.PAK	Emulator resources payload
hdd:/__common/POPS/POPS_IOX.PAK	Emulator input/output resources payload

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Controls

Navigate POPSLoader using a standard PS2 controller.

Menus & Game List

Button	Action
D-pad Up / Down	Scroll through the game list
D-pad Left / Right	Page Up / Page Down (jump through large lists)
L1	Jump to the top of the game list — press again to bounce to the bottom
R1	Refresh / rescan the current game list (forces a fresh HDD scan)
Cross (X)	Confirm option / Launch selected game
Circle (O)	Go back to the Main Menu / Cancel
Triangle (△)	Exit shortcut / BOOT.ELF shortcut where available
Start	Open the Settings / Profile Editor
Select	Toggle "Hide Text Mode" (clears the UI for a clean view of cover art)
Square (□)	Toggle cover-art preview on / off (in the game list)
L3 (left stick click)	Hide / unhide the selected game (writes/removes a <name>.hide marker — works on every device, including the internal HDD)
R3 (right stick click)	Open the per-device hidden games list (to review and unhide)
R2	Launch in "HDD Alt" mode (HDD (PFS) game list only — for an HDD-resident POPSTARTER)

On-screen Keyboard (Settings path editor)

Button	Action
L1 / R1	Move the text cursor Left / Right
Square (□)	Delete character (backspace)
R2	Toggle uppercase / lowercase

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Settings

Press Start on the menu to open Settings; changes save when you confirm. Settings persist per install with single-device parity — every device, including the internal HDD, saves a .pldrs file next to the launcher. HDD installs write that sidecar on the HDD boot partition itself (POPSLoader remounts its own boot partition read-write to do so — there is no mc0: fallback for HDD installs). For the full rules, see STATE.md > Settings.

Startup

Setting	Options	What it does
Boot Page	Carousel (default) · MX4SIO · USB · MMCE · HDD (PFS)	Where POPSLoader lands after the boot sequence. Carousel shows the normal device wheel. Pick a device and POPSLoader opens straight into that device's game list at startup (it loads that backend automatically). A -page= launch argument still overrides this for that one boot.

Game List

Setting	Options	What it does
Multi-disc games	Show all discs (default) · First disc only	First disc only hides the secondary discs of multi-disc games so only disc 1 shows. Detection is purely by filename — a disc is hidden if its name contains (Disc 2), (Disc 3), (CD 2), (Disk 2)… (any number ≥ 2). So it only works if you name your files with that convention, e.g. Final Fantasy IX (Disc 1).VCD / Final Fantasy IX (Disc 2).VCD. Launch disc 1 and swap discs in-game via your VMC. (PS1 discs carry no shared "this is the same game" metadata, so the filename is the only signal.) Applies to every device.
Hidden games	Visible (manage) (default) · Hidden	Per-game hide layer. Press L3 on any game to hide or unhide it, or R3 to open the per-device hidden list — hiding writes (or removes) a tiny <name>.hide marker next to the game's .VCD, exactly like the <name>.png cover. Hidden filters tagged games out of the list; Visible (manage) shows them dimmed so you can manage them with L3. In-app hiding works on every device — USB / MX4SIO / MMCE / Memory Card and the internal HDD (POPSLoader writes the .hide on the HDD via its read-write boot-partition mount).

Other settings

• Profile / POPSTARTER mode / POPSTARTER path — which POPSTARTER.ELF to use (a per-device profile, or a custom path).
• DKWDRV Path — path to DKWDRV.ELF used by the Disc option.
• Video Standard — Auto (default — matches your console's region) / NTSC / PAL. On PAL the UI now renders natively at 640×512 so it fills the whole screen with no letterbox (NTSC is 640×448). A display-mode change shows a confirm prompt that auto-reverts if you don't confirm, so a bad mode can't strand you; you can also hold Start during boot to skip past a bad video mode.
• BDMA Mode — mass-storage backend mode: FAT32 (FAT32-USB (None)) / USBEXFAT (exFAT-USB) / MX4SIO / MMCE. The installed mode is recorded in a bdma_mode.txt marker file in the POPSTARTER pack folder (older .pldr_bdma_mode markers are still read for compatibility).
• POPSTARTER Memory Card Folder — toggles the mc:/POPSTARTER folder. Turning it off deletes mc:/POPSTARTER (with a confirm prompt). It is interlocked with BDMA Mode: you can't turn this folder off while BDMA Mode is on, and you can't enable BDMA Mode while this folder is off.
• Hide UI Text — clears on-screen text for a clean cover-art view (also toggled with Select).
• Keyboard Layout — on-screen keyboard layout for the path editor.

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BOOT.ELF / wLaunchELF Exit

Selecting BOOT.ELF in the exit menu (or pressing the Triangle shortcut) will look for:

1. mc0:/BOOT/BOOT.ELF
2. mc1:/BOOT/BOOT.ELF

If found, BOOT.ELF launches through the embedded-loader handoff with a clean BRAM setup and an explicit argv[0]. If you do not have wLaunchELF installed at these paths, this option will fail to boot.

Hardware-confirmed working when POPSLoader was launched from USB, MC, MMCE, MX4SIO, OSDmenu, Browser, PSBBN, or HDD.

The U-10 case (BOOT.ELF exit from an HDD-launched POPSLoader) previously black-screened; it was fixed in PR #479 (reboot_iop=0), hardware-confirmed by Nuno 2026-05-31. History in docs/archive/U10_INVESTIGATION.md.

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Internal HDD Notes

• Internal HDD setups received major reliability improvements in BETA-10-5 (the "B2" PFS-unmount fix at commit 4ae6679), correcting the partition mount handoffs that previously prevented games from loading.
• Ensure that your game partition is named matching the __.POPS convention, and that the __common/POPS/ directory contains all necessary POPStarter/POPS emulator binaries.
• Existing USB/MX4SIO/MMCE setups are unaffected by the HDD fixes and should continue to work normally.

Settings Storage on HDD Installs

HDD-installed POPSLoader saves its .pldrs settings file on the HDD itself, in the launcher's boot partition — same single-device behavior as USB / MX4SIO / MMCE, which keep the sidecar at <install dir>/.pldrs. To do this POPSLoader takes over its own boot partition's mount and remounts it read-write (the OPL "own your mount" pattern), so there is no mc0: fallback for HDD installs. The same read-write mount is what lets in-app .hide markers (L3 / R3) be written on the HDD. See STATE.md > Settings for the canonical rules.

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Troubleshooting

Game does not appear in the menu list

• Using uppercase .VCD is recommended if your games are not being detected, especially on case-sensitive setups.
• Verify that VCD files are placed directly in the POPS (or __.POPS) folder, not inside subfolders.

Game launches to a black screen

• Verify that IOPRP252.IMG, POPS.ELF, and the .PAK files are present in the POPS folder.
• Check that your game image .VCD is healthy and uncorrupted.

Cover art is not showing up

• Check that the cover image is in .png format.
• The PNG filename must match the .VCD game filename exactly (e.g. Crash Bandicoot.VCD requires Crash Bandicoot.png).
• Ensure the cover art is placed in the same folder as the VCD (or __common/POPS/ART/ on HDD).
• Confirm cover-art preview is enabled — press Square (□) in the game list to toggle it.
• For best compatibility and performance, use 200x200 pixel images.

BOOT.ELF exit option fails or hangs

• Confirm that a valid wLaunchELF executable is installed on your physical memory card at mc0:/BOOT/BOOT.ELF or mc1:/BOOT/BOOT.ELF.

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Known Issues & Planned Improvements

Confirmed broken: see the single canonical STATE.md > Known Issues list (currently just the "Failed to load HDD" from a non-HDD boot case).

Planned for subsequent updates:

• Layer C Lazy IRX Loading: Defer device-specific IRX modules so they only load when the boot device family needs them, reducing boot time. The mmceman portion has landed (PR #471): it is now loaded eagerly only when POPSLoader is booted from an MMCE device, and deferred everywhere else. Further deferral of ds34bt / usbd remains future work — they are still loaded at boot today.
• Settings UI Redesign (Berion): Visual overhaul replacing the current OPL-style focused-list with per-category Settings pages. Awaiting Berion's mockup PNGs.
• GUI Themes: Customizable colors / skins / fonts and a setting to skip the boot splash.
• In-Game Features: Support for per-game fixes, cheat codes, Virtual Memory Card (VMC) setups, and multi-disc swap prompts.
• HDD (exFAT), SMB (v1), i.Link menu flows: currently surface as "Not Implemented Yet" until feature work lands.

See STATE.md "Known Open Work" and ROADMAP.md for the prioritized backlog.

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Credits

• israpps (El_isra): Original POPSLoader project creator.
• Daniel Santos: Creator of the Enceladus runtime foundation.
• krHACKen: Author of POPStarter.
• Berion: User interface design and theme assets.
• nuno6573: Cover-art engine integrations and scripting.
• Hugopocked: POPStarter fixes.
• Ripto / NathanNeurotic: Maintenance, UI polishing, and release engineering.
• P4NCHOL1NO, VizoR, provato, nuno6573, and the community: Hardware testing.

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Development & Building

GitHub Actions is the canonical build path. The pinned CI image is ps2dev/ps2dev:v2.0.0. Every change must pass the CI workflow in .github/workflows/compilation.yml before merging; rolling release artifacts for testing are produced by .github/workflows/rolling-release.yml on push to BETA-12-PLAY and on pull request events. CI now runs a live luac syntax gate over the embedded Lua (bin/POPSLDR/*.lua + etc/boot.lua) and hard-fails on a syntax error — note this catches syntax only; runtime and load-order errors still only surface on real PS2 / PCSX2.

POPSLoader is an EE C/C++ application (src/) with the entire front-end UI and launch logic written as embedded Lua (bin/POPSLDR/*.lua, etc/boot.lua) and an embedded IOP-side child ELF loader (src/elf_loader/). The Lua scripts, PNG art, IRX modules, and the child loader are all baked directly into the EE ELF at build time via bin2c, so the on-card scripts are not read at runtime — building from source is required to change them.

Developer documentation, repository architecture details, and the current state are maintained in:

• STATE.md: Current code and hardware status, the canonical Known Issues list, Behavioral Invariants, and Preservation Contracts.
• QA_REGRESSION_MATRIX.md: Complete ledger of CI gates and hardware test outcomes.
• ROADMAP.md: Prioritized backlog.
• DECISIONS.md: Decision log with rationale and evidence.
• ARCHITECTURE.md: Structural data-flow documentation.

To build the launcher binary locally (optional; CI is canonical), run:

make clean elfloader all

This cleans, force-regenerates the embedded child ELF loader (elfloader), then compiles every EE/IOP object, embeds all assets, links, strips, and runs ps2-packer to produce the packed bin/POPSLOADER.ELF. It requires a configured PS2DEV SDK environment (ps2dev/ps2dev:v2.0.0 toolchain) with ps2-packer and the bin2c tool on PATH.

To grab the latest test build, download from the rolling release URL: https://github.com/NathanNeurotic/POPSLoader/releases/download/rolling-release/POPSLOADER-rolling-release.zip