From ff92ea3b49a9fe3ba9c89adef4488862d0b8217f Mon Sep 17 00:00:00 2001
From: Vasiliy Stelmachenok <ventureo@cachyos.org>
Date: Sun, 18 May 2025 19:49:34 +0300
Subject: [PATCH] Use smart NVIDIA module loading on boot

This not only saves users from hard choices at boot, but also saves us
from a bunch of workarounds to avoid conflicts with Nouveau.

Should fix most of the black screen issues when booting ISO (but it's
not for sure...)

Signed-off-by: Vasiliy Stelmachenok <ventureo@cachyos.org>
---
 .../etc/modprobe.d/nvidia-loader.conf         |  6 ++++
 .../usr/local/bin/nvidia-module-loader        | 35 +++++++++++++++++++
 archiso/packages_desktop.x86_64               |  2 +-
 archiso/pacman.conf                           |  7 ++--
 archiso/profiledef.sh                         |  1 +
 5 files changed, 48 insertions(+), 3 deletions(-)
 create mode 100644 archiso/airootfs/etc/modprobe.d/nvidia-loader.conf
 create mode 100755 archiso/airootfs/usr/local/bin/nvidia-module-loader

diff --git a/archiso/airootfs/etc/modprobe.d/nvidia-loader.conf b/archiso/airootfs/etc/modprobe.d/nvidia-loader.conf
new file mode 100644
index 0000000..9b7e518
--- /dev/null
+++ b/archiso/airootfs/etc/modprobe.d/nvidia-loader.conf
@@ -0,0 +1,6 @@
+# Forwards all NVIDIA module load requests to a "smart" loader that selects
+# correct version of the module depending on used hardware.
+install nvidia /usr/local/bin/nvidia-module-loader
+install nvidia_drm /usr/local/bin/nvidia-module-loader
+install nvidia_uvm /usr/local/bin/nvidia-module-loader
+install nvidia_modeset /usr/local/bin/nvidia-module-loader
diff --git a/archiso/airootfs/usr/local/bin/nvidia-module-loader b/archiso/airootfs/usr/local/bin/nvidia-module-loader
new file mode 100755
index 0000000..d1558af
--- /dev/null
+++ b/archiso/airootfs/usr/local/bin/nvidia-module-loader
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Quick pass if one of the modules is already loaded.
+if [[ -e /sys/module/nvidia || -e /sys/module/nouveau ]]; then
+    exit 0
+fi
+
+# Using "install" in modprobe seems to result in no dependency resolving for
+# modules, so we have to manually set the order in which all modules are loaded
+# at once.
+load_nvidia_modules() {
+    local pkgname="$1"
+
+    # Load some basic dependencies of nvidia modules
+    modprobe video
+    modprobe drm_ttm_helper
+    modprobe drm_kms_helper
+
+    for module in nvidia nvidia-modeset nvidia-drm nvidia-uvm; do
+        modprobe --ignore-install "/usr/share/modules/${pkgname}/${module}.ko.zst"
+    done
+}
+
+# Load compatible version of NVIDIA modules for current hardware
+if chwd --list | awk '{ if($2 == "nouveau" || $2 == "nvidia-dkms-390xx" || $2 == "nvidia-dkms-470xx") f=1 } END {exit (f == 1) ? 0 : 1 }'; then
+    modprobe nouveau
+elif chwd --list | awk '{ if($2 == "nvidia-dkms") f=1 } END {exit (f == 1) ? 0 : 1 }'; then
+    load_nvidia_modules linux-cachyos-nvidia
+elif chwd --list | awk '{ if($2 == "nvidia-open-dkms") f=1 } END {exit (f == 1) ? 0 : 1 }'; then
+    load_nvidia_modules linux-cachyos-nvidia-open
+fi
+
+# Otherwise, do a fallback to nouveau anyway
+if [[ ! -e /sys/module/nouveau && ! -e /sys/module/nvidia ]]; then
+    modprobe nouveau
+fi
diff --git a/archiso/packages_desktop.x86_64 b/archiso/packages_desktop.x86_64
index da0ebcb..d9ed1ed 100644
--- a/archiso/packages_desktop.x86_64
+++ b/archiso/packages_desktop.x86_64
@@ -79,7 +79,6 @@ libusb-compat
 libwnck3
 linux-atm
 linux-cachyos
-linux-cachyos-nvidia-open
 linux-cachyos-zfs
 linux-firmware
 linux-firmware-marvell
@@ -115,6 +114,7 @@ nss-mdns
 ntfs-3g
 ntp
 nvidia-utils
+nvidia-module-extractor
 nvme-cli
 occt
 open-iscsi
diff --git a/archiso/pacman.conf b/archiso/pacman.conf
index ce63856..38df853 100644
--- a/archiso/pacman.conf
+++ b/archiso/pacman.conf
@@ -73,9 +73,12 @@ LocalFileSigLevel = Optional
 # The testing repositories are disabled by default. To enable, uncomment the
 # repo name header and Include lines. You can add preferred servers immediately
 # after the header, and they will be used before the default mirrors.
-
 [cachyos]
-SigLevel = Optional TrustAll
+# Yeah, that's dumb, but we have to do it for nvidia-module-extractor hook,
+# since mkarchiso doesn't import the keys inside rootfs for cachyos repo before
+# creating squashfs. The right solution here would be to find a way to import
+# the keys properly.
+SigLevel = Never
 Server = https://mirror.cachyos.org/repo/$arch/$repo
 
 #[core-testing]
diff --git a/archiso/profiledef.sh b/archiso/profiledef.sh
index 75ef41b..863f76c 100644
--- a/archiso/profiledef.sh
+++ b/archiso/profiledef.sh
@@ -32,4 +32,5 @@ file_permissions=(
   ["/usr/local/bin/removeun"]="0:0:755"
   ["/usr/local/bin/removeun-online"]="0:0:755"
   ["/usr/local/bin/prepare-live-desktop.sh"]="0:0:755"
+  ["/usr/local/bin/nvidia-module-loader"]="0:0:755"
 )