DerpFest 13 — Xiaomi Redmi 4X (santoni)

Unofficial DerpFest Android 13 for Xiaomi Redmi 4X (santoni).

Maintained by ziachi.

Repository Map

This build requires DerpFest source + 7 custom repos. All patches are committed to forks — no manual/local patches needed.

#	Component	Repository	Branch	Path in source tree
1	Device Tree	ziachi/device_xiaomi_santoni_derpfest	derp-13-dev	device/xiaomi/santoni
2	Kernel	ziachi/kernel_xiaomi_msm8937_derpfest	derp-13-dev	kernel/xiaomi/msm8937
3	Vendor (device)	ziachi/vendor_xiaomi_santoni_derpfest	derp-13-dev	vendor/xiaomi/santoni
4	Frameworks Base	ziachi/frameworks_base_derpfest	derp-13-dev	frameworks/base
5	Settings	ziachi/packages_apps_Settings_derpfest	derp-13-dev	packages/apps/Settings
6	Vendor (DerpFest)	ziachi/vendor_derp_derpfest	derp-13-dev	vendor/derp
7	Calendar	ziachi/packages_apps_Calendar_derpfest	derp-13-dev	packages/apps/Calendar

Build Guide

Prerequisites

• Ubuntu 22.04 (or WSL2)
• 200+ GB free disk space
• 16+ GB RAM (32 GB recommended)
• Fast internet for repo sync (~100 GB download)

Step 1 — Initialize DerpFest source

mkdir derpfest && cd derpfest
repo init -u https://github.com/DerpFest-AOSP/manifest.git -b 13 --git-lfs
repo sync -c -j$(nproc --all) --force-sync --no-clone-bundle --no-tags

Step 2 — Replace upstream repos with forks

# Remove upstream repos that we replace
rm -rf device/xiaomi/santoni kernel/xiaomi/msm8937 vendor/xiaomi/santoni \
       frameworks/base packages/apps/Settings vendor/derp packages/apps/Calendar

# Clone all custom repos
git clone -b derp-13-dev https://github.com/ziachi/device_xiaomi_santoni_derpfest.git \
  device/xiaomi/santoni

git clone -b derp-13-dev https://github.com/ziachi/kernel_xiaomi_msm8937_derpfest.git \
  kernel/xiaomi/msm8937

git clone -b derp-13-dev https://github.com/ziachi/vendor_xiaomi_santoni_derpfest.git \
  vendor/xiaomi/santoni

git clone -b derp-13-dev https://github.com/ziachi/frameworks_base_derpfest.git \
  frameworks/base

git clone -b derp-13-dev https://github.com/ziachi/packages_apps_Settings_derpfest.git \
  packages/apps/Settings

git clone -b derp-13-dev https://github.com/ziachi/vendor_derp_derpfest.git \
  vendor/derp

git clone -b derp-13-dev https://github.com/ziachi/packages_apps_Calendar_derpfest.git \
  packages/apps/Calendar

Step 3 — Fix linker symlink

ln -sf $(pwd)/prebuilts/clang/host/linux-x86/clang-r450784d/bin/ld.lld \
  prebuilts/build-tools/path/linux-x86/ld

This is a build environment fix — ld is missing from AOSP build-tools for kernel compilation.

Step 4 — Build

source build/envsetup.sh
lunch derp_santoni-userdebug
mka derp -j$(nproc)

Build output: out/target/product/santoni/DerpFest-13-Unofficial-Tango-santoni-*.zip

Step 5 — Flash

1. Boot into custom recovery (TWRP / OrangeFox)
2. Wipe System, Data, Cache, Dalvik
3. Flash DerpFest-13-Unofficial-*.zip
4. (Optional) Flash GApps ZIP — Pico/Nano recommended (system partition is 3 GB)
5. Reboot

Build Notes

• Vanilla build — no GApps included (3 GB system partition too small for built-in GApps)
• Uses AOSP clang r450784d for kernel compilation
• SELinux: Enforcing
• Spectrum kernel profiles — Balance / Performance / Battery / Gaming (Quick Settings tile)
• Setup Wizard — set to OPTIONAL (auto-provisions when no Setup Wizard present)
• LiveDisplay — disabled (MSM8937 has no SDM HAL support)
• Power HAL — uses AOSP example HAL (QTI AIDL v3 incompatible with kernel 4.9)

Custom Patches in Forks

frameworks_base_derpfest

Commit	Description
2851d711	Spectrum QS tile — Quick Settings tile for kernel profile switching
0faf8796	SystemUIGoogle privapp permissions — add missing allowlist entries
a3d667c5	Reticker crash fix — isAttachedToWindow() guard before createCircularReveal()

packages_apps_Settings_derpfest

Commit	Description
0b559483	Set maintainer info to ziachi

vendor_derp_derpfest

Commit	Description
24cb349	Make WITH_GMS conditional — allows vanilla build without GApps

packages_apps_Calendar_derpfest

Commit	Description
95291a1	Fix FragmentManager crash in GeneralPreferences (vanilla build)

For AI Agents

If you're an AI agent building this ROM, here's the quick reference:

# Full build sequence (after repo sync + clones + ld symlink)
cd ~/derpfest
source build/envsetup.sh
lunch derp_santoni-userdebug
mka derp -j$(nproc)

Key facts:

• Lunch target: derp_santoni-userdebug
• Build command: mka derp (NOT mka bacon)
• Vendor inherit: vendor/derp/config/common_full_phone.mk
• Clang version: r450784d (NOT zyc_clang)
• WITH_GMS := false in derp_santoni.mk
• System partition: 3 GB max — vanilla only
• SELinux must stay Enforcing
• All patches are in fork repos — clone all 7 repos from the Repository Map

Common build errors:

Error	Fix
ld not found in sbox	Symlink ld → ld.lld in prebuilts/build-tools/path/linux-x86/
System image too large	Ensure WITH_GMS := false in derp_santoni.mk
Power HAL bootloop	Already fixed — uses android.hardware.power-service.example

Screenshots

About Phone	Recents + Play Integrity

Spec Sheet

Feature	Specification
CPU	Octa-core 1.4 GHz Cortex-A53
Chipset	Qualcomm MSM8940 Snapdragon 435
GPU	Adreno 505
Memory	2/3 GB
Shipped Android Version	6.0.1
Storage	16/32 GB
MicroSD	Up to 256 GB
Battery	4100 mAh (non-removable)
Dimensions	139 x 69 x 8.65 mm
Display	720 x 1280 pixels, 5" (~294 PPI)
Rear Camera	13 MP, LED flash
Front Camera	5 MP
Release Date	May 2017

Credits

• androidsantoni — Original device tree (RisingOS 13 base)
• DerpFest-AOSP — ROM source

Changelog

See CHANGELOG.md