From b4949703f2f4741081accf74072f7610789d4e02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= <ffidencio@nvidia.com>
Date: Thu, 11 Jun 2026 14:44:22 +0200
Subject: [PATCH] fixup! build: split NVIDIA rootfs into base-nvidia image +
 gpu addon

---
 .../rootfs-builder/nvidia/nvidia_rootfs.sh    | 34 ++++++++++++++++++-
 .../static-build/busybox/busybox.nvidia.conf  | 16 +++++----
 2 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/tools/osbuilder/rootfs-builder/nvidia/nvidia_rootfs.sh b/tools/osbuilder/rootfs-builder/nvidia/nvidia_rootfs.sh
index d50f4de74a..b1c3e20872 100644
--- a/tools/osbuilder/rootfs-builder/nvidia/nvidia_rootfs.sh
+++ b/tools/osbuilder/rootfs-builder/nvidia/nvidia_rootfs.sh
@@ -553,6 +553,38 @@ chisseled_veritysetup() {
 	cp -a "${stage_one}/${libdir}"/libcap.so.2*            "${libdir}/."
 }
 
+# NVRC loads each addon's NVIDIA kernel modules from that addon's self-contained
+# module tree via `modprobe --dirname <addon>` (a kmod feature). The base ships
+# busybox, whose modprobe is built without long options and has no --dirname, so
+# the base must carry the real kmod. This keeps modules composable: every
+# module-bearing addon stays independent (its own modules.dep from depmod -b) and
+# nothing has to shadow the read-only /lib/modules. kmod is a single multi-call
+# binary that embeds libkmod (no libkmod2 to ship); modprobe/insmod/... are
+# argv[0] symlinks to it. Runs inside ${ROOTFS_DIR}.
+chisseled_kmod() {
+	echo "nvidia: chisseling kmod"
+
+	local libdir="lib/${machine_arch}-linux-gnu"
+
+	cp -a "${stage_one}/usr/bin/kmod" usr/bin/.
+
+	# kmod picks its applet from argv[0]. Expose the module tools as symlinks;
+	# /sbin/modprobe (NVRC's absolute path) shadows the busybox modprobe applet.
+	# Absolute targets so they resolve regardless of whether /sbin is a real dir
+	# or a usr-merge symlink.
+	local tool
+	for tool in modprobe insmod rmmod depmod lsmod; do
+		ln -sf /usr/bin/kmod "sbin/${tool}"
+	done
+
+	# kmod links libzstd/liblzma unconditionally (compressed-module support);
+	# our modules are uncompressed but the NEEDED entries must still resolve.
+	# libcrypto/libc are already present (libc from chisseled_compute, libcrypto
+	# from chisseled_veritysetup).
+	cp -a "${stage_one}/${libdir}"/libzstd.so.1*  "${libdir}/."
+	cp -a "${stage_one}/${libdir}"/liblzma.so.5*  "${libdir}/."
+}
+
 setup_nvidia_gpu_rootfs_stage_two() {
 	readonly stage_two="${ROOTFS_DIR:?}"
 	readonly stack="${NVIDIA_GPU_STACK:?}"
@@ -617,7 +649,7 @@ setup_nvidia_gpu_rootfs_stage_two() {
 		# Carve the freshly chiseled (monolith) tree into the requested layout.
 		# The monolith path is left untouched.
 		case "${layout}" in
-			base) partition_base; chisseled_veritysetup ;;
+			base) partition_base; chisseled_veritysetup; chisseled_kmod ;;
 			gpu-addon) partition_gpu_addon ;;
 		esac
 	fi
diff --git a/tools/packaging/static-build/busybox/busybox.nvidia.conf b/tools/packaging/static-build/busybox/busybox.nvidia.conf
index 21b2e7ffeb..66cac10af7 100644
--- a/tools/packaging/static-build/busybox/busybox.nvidia.conf
+++ b/tools/packaging/static-build/busybox/busybox.nvidia.conf
@@ -564,14 +564,18 @@ CONFIG_FEATURE_DEFAULT_PASSWD_ALGO=""
 # CONFIG_LSMOD is not set
 # CONFIG_FEATURE_LSMOD_PRETTY_2_6_OUTPUT is not set
 # CONFIG_MODINFO is not set
-CONFIG_MODPROBE=y
-CONFIG_FEATURE_MODPROBE_BLACKLIST=y
+# CONFIG_MODPROBE is not set
+# CONFIG_FEATURE_MODPROBE_BLACKLIST is not set
 # CONFIG_RMMOD is not set
 
 #
 # Options common to multiple modutils
 #
-CONFIG_FEATURE_CMDLINE_MODULE_OPTIONS=y
+# The base-nvidia image ships the real kmod (modprobe/insmod/...) so that NVRC
+# can load each addon's modules with `modprobe --dirname <addon>`; busybox's
+# modprobe lacks long options (no --dirname), so all busybox modutils are
+# disabled here to avoid a dead, conflicting applet shadowing kmod.
+# CONFIG_FEATURE_CMDLINE_MODULE_OPTIONS is not set
 # CONFIG_FEATURE_MODPROBE_SMALL_CHECK_ALREADY_LOADED is not set
 # CONFIG_FEATURE_2_4_MODULES is not set
 # CONFIG_FEATURE_INSMOD_VERSION_CHECKING is not set
@@ -581,10 +585,8 @@ CONFIG_FEATURE_CMDLINE_MODULE_OPTIONS=y
 # CONFIG_FEATURE_INSMOD_LOAD_MAP_FULL is not set
 # CONFIG_FEATURE_CHECK_TAINTED_MODULE is not set
 # CONFIG_FEATURE_INSMOD_TRY_MMAP is not set
-CONFIG_FEATURE_MODUTILS_ALIAS=y
-CONFIG_FEATURE_MODUTILS_SYMBOLS=y
-CONFIG_DEFAULT_MODULES_DIR="/lib/modules"
-CONFIG_DEFAULT_DEPMOD_FILE="modules.dep"
+# CONFIG_FEATURE_MODUTILS_ALIAS is not set
+# CONFIG_FEATURE_MODUTILS_SYMBOLS is not set
 
 #
 # Linux System Utilities