sys-patch

A script-like system module that patches fs, es, ldr and nifm on boot.

Config

sys-patch features a simple config. This can be manually edited or updated using the overlay.

The configuration file can be found in /config/sys-patch/config.ini. The file is generated once the module is ran for the first time.

[options]
patch_sysmmc=1   ; 1=(default) patch sysmmc, 0=don't patch sysmmc
patch_emummc=1   ; 1=(default) patch emummc, 0=don't patch emummc
enable_logging=1 ; 1=(default) output /config/sys-patch/log.ini 0=no log
version_skip=1   ; 1=(default) skips out of date patterns, 0=search all patterns

Overlay

The overlay can be used to change the config options and to see what patches are applied.

Unpatched means the patch wasn’t applied (likely not found).
Patched (green) means it was patched by sys-patch.
Patched (yellow) means it was already patched, likely by sigpatches or a custom Atmosphere build.

Building

prerequisites

Install devkitpro

Run the following:

git clone --recurse-submodules https://github.com/ITotalJustice/sys-patch.git
cd ./sys-patch
make

The output of out/ can be copied to your SD card. To activate the sys-module, reboot your switch, or, use sysmodules overlay with the accompanying overlay to activate it.

What is being patched?

Here’s a quick run down of what’s being patched:

fs
es
ldr
nifm

fs and es need new patches after every new firmware version. ldr needs new patches after every new Atmosphere release. nifm ctest patch allows the device to connect to a network without needing to make a connection to a server.

The patches are applied on boot. Once done, the sys-module stops running. The memory footprint (16kib) and the binary size (~50kib) are both very small.

FAQ:

If I am using sigpatches already, is there any point in using this?

Yes, in 3 situations.

A new ldr patch needs to be created after every Atmosphere update. Sometimes, a new silent Atmosphere update is released. This tool will always patch ldr without having to update patches.
Building Atmosphere from src will require you to generate a new ldr patch for that custom built Atmosphere. This is easy enough due to the public scripts / tools that exist out there, however this will always be able to patch ldr.
If you forget to update your patches when you update your firmware / Atmosphere, this sys-module should be able to patch everything. So it can be used as a fall back.

Does this mean that I should stop downloading / using sigpatches?

No, I would personally recommend continuing to use sigpatches. Reason being is that should this tool ever break, i likely wont be quick to fix it.

Credits / Thanks

Software is built on the shoulders of giants. This tool wouldn’t be possible without these people:

MrDude
BornToHonk (farni)
TeJay
ArchBox
Switchbrew (libnx, switch-examples)
DevkitPro (toolchain)
minIni
libtesla
Shoutout to the best switch cfw setup guide
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