Andrew Quenehen
3fae3088ca
A running launcher cannot replace its own NRO on sdmc/FAT; stage the new binary and chainload a tiny helper from romfs to swap it in before loading the game.
Native Switch OTA launcher
In-console updates for Gen1Recomp on Nintendo Switch. This NRO is the hbmenu
entry (gen1recomp.nro). It checks GitHub Releases quietly (no UI when you
are already up to date or offline). Only if a newer release exists does it show
a launcher-style screen (black + RGB rail + project logo + flat A/B
buttons), download the same gen1recomp-*-switch.zip used for install, verify
SHA-256 from sha256sums.txt, replace both gen1recomp-game.nro and
gen1recomp.nro (matching NACP version for hbmenu/Sphaira), then load the game
with envSetNextLoad.
The LÖVE self-updater (src/update/Check.lua) stays disabled on NX.
Wire format (also in Lua): src/update/SwitchOta.lua.
NACP icon: assets/switch/icon.jpg.
Layout on microSD
sdmc:/switch/gen1recomp/gen1recomp.nro <- this launcher
sdmc:/switch/gen1recomp/gen1recomp-game.nro <- fused LÖVE game
sdmc:/switch/gen1recomp/version.txt <- installed X.Y.Z
sdmc:/switch/gen1recomp/pokemon-love2d/ <- saves (never touched by OTA)
Host tests (no DEVKITPRO)
cd native/switch-ota-launcher
make host-test
Switch build (DEVKITPRO)
Needs DEVKITPRO with packages roughly:
(dkp-)pacman -S --needed switch-curl switch-mbedtls switch-zlib switch-zziplib
# or: bash scripts/switch/install_devkitpro_deps.sh
export DEVKITPRO=/opt/devkitpro # typical
cd native/switch-ota-launcher
make
# -> gen1recomp.nro
Or from repo root (as part of --fused):
scripts/build_switch.sh --fetch --fused --version X.Y.Z
Standalone launcher build:
scripts/switch/build_ota_launcher.sh
Docker fallback uses the same pin as fused builds (scripts/switch/dkp-docker.image).
Packaging
scripts/switch/pack_sd_zip.sh GAME_NRO VERSION OUT_ZIP LAUNCHER_NRO writes both
NROs into the SD zip. That zip is also what OTA downloads.
Manifest: scripts/switch/ota_launcher.manifest.
Status / known gaps
- Zip extraction uses
switch-zziplib(ota_unzip.c) on device. - OTA replaces game + launcher from the install zip (NACP versions stay aligned).
The running launcher cannot overwrite its own NRO on sdmc/FAT; a tiny
ota-bootstrap.nro(embedded in romfs) chainloads once to swap the staged launcher, then loads the game. - HTTPS uses Mozilla CA bundle in romfs (
cacert.pem, fetched at build time).ota_net_init()mounts romfs before the quiet release check. - Sphaira HOME forwarders cache metadata until reinstalled (see docs/switch-install.md).
- Release runner:
switch-dev+ (install_devkitpro_deps.shor Docker)