Thank you for opening a new issue. To help solve it faster and more easily, please review this check-list, and fill in the sections below. Adapt as needed. Do not open an issue to request a new feature; instead, post a message to [the mailing list](https://lists.buildroot.org/mailman/listinfo/buildroot). _Note: issues missing any information may get closed without further ado._ --- ### Check-list - [x] I did not find the issue in the existing issues - [x] I can reproduce the issue with unmodified Buildroot from [this repository](https://gitlab.com/buildroot.org/buildroot), not from a fork somewhere else - [x] I can reproduce the issue on the latest commit of the branch I'm using: - [ ] master - [x] stable 2026.02.1 - [ ] LTS (i.e. 20NN.02.x - please specify) - [x] I can reproduce the issue after running `make clean; make` - [ ] I attached the full build log file (e.g. `make 2>&1 |tee build.log`) - [x] I attached a **minimal** defconfig file that can reproduce the issue (`make BR2_DEFCONFIG=$(pwd)/issue_defconfig savedefconfig`) - [ ] I also attached the configuration for kconfig-based packages that are enabled (and necessary to reproduce the issue), most notably: - [ ] busybox - [ ] linux - [ ] uclibc - [ ] uboot - [ ] … --- ### What I did - **Buildroot commit sha1**: 0141ca3fa5302c0c3c583cb898bd3f8792bced69 - **Distribution of the build machine**: Debian GNU/Linux 13 (trixie) `issue_defconfig` file: ``` BR2_aarch64=y BR2_TOOLCHAIN_BUILDROOT_CXX=y BR2_PACKAGE_MESA3D=y BR2_PACKAGE_MESA3D_LLVM=y BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_PANFROST=y ``` --- ### What happens Enabling option `BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_PANFROST` currently requires target-side LLVM, which makes the target image bloated (~100MB extra size for LLVM). This is since commit https://gitlab.com/buildroot.org/buildroot/-/commit/2f7bcc7dfc521772a395aba084eba31e6622e94d. With this commit, `BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_PANFROST` gained depends on `BR2_PACKAGE_MESA3D_LLVM` and started selecting `BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER`. That option pulls in: - `BR2_PACKAGE_MESA3D_OPENCL` (Clover) — which depends on `BR2_PACKAGE_MESA3D_LLVM` and selects `LLVM_RTTI`, `CLANG`, `LIBCLC` - `BR2_PACKAGE_SPIRV_LLVM_TRANSLATOR` — which selects `BR2_PACKAGE_LLVM` - `BR2_PACKAGE_SPIRV_TOOLS` The commit message says two things: "Panfrost driver depends on llvm […] and needs the host tool panfrost_compile". However, only the second is true. --- ### What was expected In fact, target-side LLVM should not be needed when only OpenGL support is needed. Mesa only requires LLVM for building Panfrost’s precompiled shader tools; when those tools are provided by host-mesa3d, target Mesa can be built with `-Dllvm=disabled`. Actually, <mesa source code>`docs/drivers/panfrost.rst` documents cross-build mode: build the host tools with LLVM, then use `-Dmesa-clc=system -Dprecomp-compiler=system` on the target side. --- ### Extra information I used LLM to create a patch by giving it all necessary information including mesa3d source code. This patch (attached below) is tested by human (me) to build and run correctly on an actual Rockchip board. With this patch applied, panfrost no longer requires target-side LLVM. This patch is for reference only, and I would kindly like to request a maintainer to edit & merge it, if looks good. The patch currently fixes the problem only for Panfrost; however, the following four drivers may also benefit from the same principle, and it would be nice if the maintainer can look into it. * Iris (gallium) * Intel (vulkan) * Imagination (vulkan) * Crocus <details> <summary>Click to expand the AI-generated, human-verified patch</summary> ```patch From a5359aefe1508eb8aef4c0dfcddc8fb6f0f2ebd7 Mon Sep 17 00:00:00 2001 From: User <user@user.com> Date: Tue, 19 May 2026 16:43:26 +0800 Subject: [PATCH] package/mesa3d: allow gallium panfrost without target llvm Mesa's Panfrost Gallium driver needs LLVM for building its precompiled shader tools, but those tools do not have to be built for or installed on the target. Mesa documents the cross-compilation flow as building mesa_clc, vtn_bindgen2, and panfrost_compile on the host, then using -Dmesa-clc=system and -Dprecomp-compiler=system for the target build. Buildroot already builds those tools through host-mesa3d. Split the Panfrost dependency from the existing target-side precompile path by adding a host-only precompile marker. Use it for Gallium Panfrost so that selecting the driver no longer forces BR2_PACKAGE_MESA3D_LLVM, Mesa OpenCL, target clang, target libclc, or the target SPIR-V translator stack. Keep the existing BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER path for the other users that still rely on the previous target-side dependency model. Also make the target SPIRV-Tools Meson option explicit: enable it for RustiCL, where CLC requires it, and disable it otherwise to avoid accidental target-side optional dependency pickup. Finally, pass cpp_rtti explicitly to host-mesa3d so its C++ RTTI mode continues to match host-llvm even when Panfrost no longer selects the target LLVM/OpenCL path. --- package/mesa3d/Config.in | 14 ++++++++++---- package/mesa3d/mesa3d.mk | 21 +++++++++++++++++---- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/package/mesa3d/Config.in b/package/mesa3d/Config.in index 8a7811b6a5..eea8f6d4ff 100644 --- a/package/mesa3d/Config.in +++ b/package/mesa3d/Config.in @@ -27,6 +27,10 @@ config BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER select BR2_PACKAGE_SPIRV_LLVM_TRANSLATOR select BR2_PACKAGE_SPIRV_TOOLS +config BR2_PACKAGE_MESA3D_NEEDS_HOST_PRECOMP_COMPILER + bool + select BR2_HOST_CMAKE_AT_LEAST_3_20 # host-llvm + config BR2_PACKAGE_MESA3D_LLVM bool "llvm support" depends on BR2_PACKAGE_LLVM_ARCH_SUPPORTS @@ -203,15 +207,17 @@ config BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_NOUVEAU config BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_PANFROST bool "Gallium panfrost driver" depends on BR2_TOOLCHAIN_HAS_SYNC_4 || !BR2_PACKAGE_XORG7 # libxshmfence - depends on BR2_PACKAGE_MESA3D_LLVM + depends on BR2_PACKAGE_LLVM_ARCH_SUPPORTS # host-llvm + depends on BR2_HOST_GCC_AT_LEAST_7 # host-llvm select BR2_PACKAGE_MESA3D_GALLIUM_DRIVER - select BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER + select BR2_PACKAGE_MESA3D_NEEDS_HOST_PRECOMP_COMPILER select BR2_PACKAGE_MESA3D_RUSTICL_SUPPORTED_DRIVER help Mesa driver for ARM Mali Midgard and Bifrost GPUs. -comment "panfrost driver needs llvm" - depends on !BR2_PACKAGE_MESA3D_LLVM +comment "panfrost driver needs host gcc >= 7" + depends on BR2_PACKAGE_LLVM_ARCH_SUPPORTS + depends on !BR2_HOST_GCC_AT_LEAST_7 config BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_R300 bool "Gallium Radeon R300 driver" diff --git a/package/mesa3d/mesa3d.mk b/package/mesa3d/mesa3d.mk index f082d3c429..72cfd9bc9d 100644 --- a/package/mesa3d/mesa3d.mk +++ b/package/mesa3d/mesa3d.mk @@ -69,14 +69,17 @@ MESA3D_DEPENDENCIES += \ MESA3D_CONF_OPTS += \ -Dgallium-rusticl=true \ -Drust_std=2021 \ - -Dmesa-clc-bundle-headers=enabled + -Dmesa-clc-bundle-headers=enabled \ + -Dspirv-tools=enabled MESA3D_MESON_EXTRA_BINARIES += \ rust=['$(HOST_DIR)/bin/rustc','--target=$(RUSTC_TARGET_NAME)'] \ rust_ld='$(TARGET_CROSS)gcc' else -MESA3D_CONF_OPTS += -Dgallium-rusticl=false +MESA3D_CONF_OPTS += \ + -Dgallium-rusticl=false \ + -Dspirv-tools=disabled endif ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_ELFUTILS),y) @@ -152,9 +155,13 @@ ifeq ($(BR2_PACKAGE_MESA3D_VULKAN_DRIVER_INTEL),y) MESA3D_DEPENDENCIES += host-python-ply endif -ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER),y) +ifneq ($(BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER)$(BR2_PACKAGE_MESA3D_NEEDS_HOST_PRECOMP_COMPILER),) MESA3D_CONF_OPTS += -Dmesa-clc=system -Dprecomp-compiler=system -MESA3D_DEPENDENCIES += host-mesa3d spirv-llvm-translator spirv-tools +MESA3D_DEPENDENCIES += host-mesa3d +endif + +ifeq ($(BR2_PACKAGE_MESA3D_NEEDS_PRECOMP_COMPILER),y) +MESA3D_DEPENDENCIES += spirv-llvm-translator spirv-tools endif ifeq ($(BR2_PACKAGE_MESA3D_VULKAN_DRIVER),) @@ -310,6 +317,12 @@ HOST_MESA3D_CONF_OPTS = \ -Dglx=disabled \ -Dvulkan-drivers="" +ifeq ($(BR2_PACKAGE_LLVM_RTTI),y) +HOST_MESA3D_CONF_OPTS += -Dcpp_rtti=true +else +HOST_MESA3D_CONF_OPTS += -Dcpp_rtti=false +endif + HOST_MESA3D_DEPENDENCIES = \ host-libclc \ host-libdrm \ -- 2.47.3 ``` </details>