kamb205--KB-RPCS3/BUILDING.md

Building KB-RPCS3 from source

KB-RPCS3 has two separately licensed parts that are combined only at build time, on your own machine:

Part	Folder	Licence
RPCS3 + the KB-RPCS3 core patches	port/rpcs3-patches/ (applied to upstream RPCS3)	GPL-2.0-only (RPCS3's licence)
The PS5 title shell (home screen, settings, installer, PS5 platform glue)	app/	mixed — see app/LICENSING.md (MIT base, GPL-3.0-or-later UI and title code)

Read LICENSING_STATUS.md before distributing anything you build: a binary that combines both parts cannot currently be distributed.

Status of these instructions: they describe the build exactly as it was done for Alpha 0.1.0. That build ran in an Ubuntu (arm64) virtual machine with the PS5 toolchain installed at fixed paths under ~/work/. The scripts in port/ and tools/ still assume that layout. Reproducing the build on another machine requires the same dependencies at the same paths, or editing the paths in the scripts. A portable build is planned; it is not part of this alpha.

1. Dependencies (fetched separately, not included here)

Dependency	Used for	Licence
Upstream RPCS3 at revision 46aee28f8 (with its git submodules)	the emulator core	GPL-2.0-only (+ submodule licences)
PS5_Vulkan (Mihawk) — RADV/Mesa build for the PS5, link recipe, native ELF/SELF tool, libc.prx	graphics driver and title packaging	GPL-3.0 (Mesa/RADV parts: MIT)
ps5-payload-sdk (ps5-payload-dev) and its fork with the PS5 platform layer (Mihawk)	toolchain, headers, platform library	GPL-3.0-or-later
PS5_VKHomebrewUI (Mihawk's fork of BlackBearReloaded's ps5-homebrew-ui)	the UI kit, fetched by app/ps5/ui/setup-kit.sh	GPL-3.0
LLVM, FFmpeg, libiconv and zlib built for the PS5	linked by the emulator core	Apache-2.0 WITH LLVM-exception, LGPL/GPL, LGPL, Zlib
Vulkan-Headers 1.4.354 and volk 1.4.350.1	Vulkan loading	Apache-2.0 / MIT

The LLVM/FFmpeg/libiconv/zlib PS5 builds used for the alpha came from a separate PS5 RetroArch build's dependency folder; port/rpcs3-build.sh shows the exact paths it expects.

2. Apply the RPCS3 patch series

port/apply-rpcs3-patches.sh /path/to/rpcs3

This clones upstream RPCS3, checks out 46aee28f8, initialises the submodules and applies the 47 patches with git am --keep-cr. The --keep-cr is required: some upstream files use CRLF line endings.

3. Build the emulator core

SRC_DIR=/path/to/rpcs3 BUILD_DIR=/path/to/rpcs3-build JOBS=8 port/rpcs3-build.sh rpcs3_ps5

• Leave EXTRA_CFLAGS empty. The working configuration uses emulated TLS. Native TLS (-fno-emulated-tls) failed on real hardware (KNOWN_ISSUES.md).
• Set CCACHE_DISABLE=1 when you need trustworthy compiler diagnostics.
• A full build takes about two hours on an 8-core machine. It ends with BUILD OK and writes rpcs3-link-inputs.txt, the list of static archives the title links.

4. Build the title

APP_DIR=/path/to/app-build-copy RPCS3_BUILD_DIR=/path/to/rpcs3-build tools/vm-build-app.sh

The title is written to dist/PPSA99303/. Do not set PS5_NATIVE_TLS=1.

Optional: the per-game recommended settings need RPCS3's configuration database, which is not redistributed here. Download it before building:

mkdir -p app/examples/rpcs3ps5/data
curl -o app/examples/rpcs3ps5/data/rpcs3-config-db.json 'https://api.rpcs3.net/config/?api=v1'

5. Experimental options

All experimental SPU options are off by default. They are switched on per console with a tuning file, rpcs3/ps5-tuning.txt in the title folder, one key value per line:

Key	Default	Meaning
spu_insert_select	0	SPU LLVM: variable-index insert as a lane select
spu_narrow_ls_store	0	SPU LLVM: narrow local-store store for load → insert → store
spu_narrow_ls_check	0	debug: verify every narrow store against the full store
spu_hot_cpu	-1	keep the busiest SPU thread on the given CPU (12 = the CPU without an SMT sibling)
spu_jit_verify	0	debug: LLVM IR verification of all compiled SPU code

None of these is a validated improvement yet.