Working with third party fork of linux kernel

First let me say: this is not your problem. It is mine and Xilinx's problem.
The code is here: https://github.com/Xilinx/linux-xlnx
It is based on version 6.1.0 of the official kernel repo.
I'm debugging the displayport output of a Xilinx MPSOC development board (specifically the Avnet UltraZed EV Carrier Board).
The display port out works on boot up once in a while. There are very few messages in dmesg when it doesn't work.
The code I am debugging is custom and written by Xilinx engineers. It is written to be kernel modules, but was by default set to be compiled in.
I changed the code to [M] so I could delay loading it until after boot to help with timing and to make debugging the code easier. (also because I thought there might be a race condition that is handled by the time the system is booted)
Changing to [M]odule required MODULE_LICENSE to be added to three C source codes and around 60 EXPORT_SYMBOL directives to be added.
However, after doing all that the kernel won't compile and because I'm a kernel novice I don't know what's going on. Here are the compiler errors:
LD [M] drivers/gpu/drm/xlnx/zynqmp-dpsub.ko LD .tmp_vmlinux.kallsyms1 ld: Unexpected GOT/PLT entries detected! ld: Unexpected run-time procedure linkages detected! ld: ID map text too big or misaligned ld: drivers/gpu/drm/display/drm_dp_mst_topology.o: in function `drm_dp_mst_duplicate_state': /usr/src/linux/drivers/gpu/drm/display/drm_dp_mst_topology.c:4951: undefined reference to `__drm_atomic_helper_private_obj_duplicate_state' ld: drivers/gpu/drm/display/drm_dp_mst_topology.o: in function `drm_dp_delayed_destroy_work': /usr/src/linux/drivers/gpu/drm/display/drm_dp_mst_topology.c:4937: undefined reference to `drm_kms_helper_hotplug_event' ld: drivers/gpu/drm/display/drm_dp_mst_topology.o: in function `drm_dp_mst_up_req_work': /usr/src/linux/drivers/gpu/drm/display/drm_dp_mst_topology.c:3979: undefined reference to `drm_kms_helper_hotplug_event' ld: drivers/gpu/drm/display/drm_dp_mst_topology.o: in function `drm_dp_mst_link_probe_work': /usr/src/linux/drivers/gpu/drm/display/drm_dp_mst_topology.c:2689: undefined reference to `drm_kms_helper_hotplug_event' make[1]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1 make: *** [Makefile:1236: vmlinux] Error 2
I have checked and those references are defined in actual headers and in c code. I verified the the .o files have at least the text of those references.
I'm hoping one of you will have mercy on a newb and help me out.
I'm using gcc:
ultrazed ~ # gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/aarch64-unknown-linux-gnu/12/lto-wrapper Target: aarch64-unknown-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-12.3.1_p20230526/work/gcc-12-20230526/configure --host=aarch64-unknown-linux-gnu --build=aarch64-unknown-linux-gnu --prefix=/usr --bindir=/usr/aarch64-unknown-linux-gnu/gcc-bin/12 --includedir=/usr/lib/gcc/aarch64-unknown-linux-gnu/12/include --datadir=/usr/share/gcc-data/aarch64-unknown-linux-gnu/12 --mandir=/usr/share/gcc-data/aarch64-unknown-linux-gnu/12/man --infodir=/usr/share/gcc-data/aarch64-unknown-linux-gnu/12/info --with-gxx-include-dir=/usr/lib/gcc/aarch64-unknown-linux-gnu/12/include/g++-v12 --with-python-dir=/share/gcc-data/aarch64-unknown-linux-gnu/12/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --disable-libunwind-exceptions --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 12.3.1_p20230526 p2' --with-gcc-major-version-only --enable-libstdcxx-time --enable-lto --disable-libstdcxx-pch --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-fixed-point --enable-libgomp --disable-libssp --disable-libada --disable-cet --disable-systemtap --disable-valgrind-annotations --disable-vtable-verify --disable-libvtv --without-zstd --without-isl --enable-default-pie --enable-default-ssp Thread model: posix Supported LTO compression algorithms: zlib gcc version 12.3.1 20230526 (Gentoo 12.3.1_p20230526 p2)
Answers
-
So I'm learning more about Kconfig. I think I found an issue related to this.
The Xilinx GPU driver is using select DRM_KMS_HELPER in it's Kconfig, which is setting DRM_KMS_HELPER=m which causes the Makefile to exclude the very files that are needed.
# # Modesetting helpers # drm_kms_helper-y := drm_bridge_connector.o drm_crtc_helper.o \ drm_encoder_slave.o drm_flip_work.o \ drm_probe_helper.o \ drm_plane_helper.o drm_atomic_helper.o \ drm_kms_helper_common.o \ drm_simple_kms_helper.o drm_modeset_helper.o \ drm_gem_atomic_helper.o \ drm_gem_framebuffer_helper.o \ drm_atomic_state_helper.o drm_damage_helper.o \ drm_format_helper.o drm_self_refresh_helper.o drm_rect.o drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
I'm trying to figure out how to get DRM_KMS_HELPER=y but google hasn't shown me the light yet.
Can someone point me the right direction?
Nevermind I changed Makefile to assign this: drm_kms_helper-($CONFIG_DRM_KMS_HELPER)) and it still generated the same error messages.
0
Categories
- All Categories
- 230 LFX Mentorship
- 230 LFX Mentorship: Linux Kernel
- 812 Linux Foundation IT Professional Programs
- 365 Cloud Engineer IT Professional Program
- 183 Advanced Cloud Engineer IT Professional Program
- 82 DevOps Engineer IT Professional Program
- 151 Cloud Native Developer IT Professional Program
- 138 Express Training Courses & Microlearning
- 138 Express Courses - Discussion Forum
- Microlearning - Discussion Forum
- 6.4K Training Courses
- 48 LFC110 Class Forum - Discontinued
- 71 LFC131 Class Forum
- 44 LFD102 Class Forum
- 228 LFD103 Class Forum
- 19 LFD110 Class Forum
- 42 LFD121 Class Forum
- 18 LFD133 Class Forum
- 8 LFD134 Class Forum
- 18 LFD137 Class Forum
- 71 LFD201 Class Forum
- 5 LFD210 Class Forum
- 5 LFD210-CN Class Forum
- 2 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum - Discontinued
- 2 LFD233 Class Forum
- 4 LFD237 Class Forum
- 24 LFD254 Class Forum
- 702 LFD259 Class Forum
- 111 LFD272 Class Forum - Discontinued
- 4 LFD272-JP クラス フォーラム
- 13 LFD273 Class Forum
- 186 LFS101 Class Forum
- 1 LFS111 Class Forum
- 3 LFS112 Class Forum
- 3 LFS116 Class Forum
- 7 LFS118 Class Forum
- LFS120 Class Forum
- 9 LFS142 Class Forum
- 8 LFS144 Class Forum
- 4 LFS145 Class Forum
- 3 LFS146 Class Forum
- 2 LFS148 Class Forum
- 15 LFS151 Class Forum
- 4 LFS157 Class Forum
- 45 LFS158 Class Forum
- LFS158-JP クラス フォーラム
- 10 LFS162 Class Forum
- 2 LFS166 Class Forum
- 4 LFS167 Class Forum
- 3 LFS170 Class Forum
- 2 LFS171 Class Forum
- 3 LFS178 Class Forum
- 3 LFS180 Class Forum
- 2 LFS182 Class Forum
- 5 LFS183 Class Forum
- 32 LFS200 Class Forum
- 737 LFS201 Class Forum - Discontinued
- 3 LFS201-JP クラス フォーラム - Discontinued
- 19 LFS203 Class Forum
- 135 LFS207 Class Forum
- 2 LFS207-DE-Klassenforum
- 1 LFS207-JP クラス フォーラム
- 302 LFS211 Class Forum
- 56 LFS216 Class Forum
- 52 LFS241 Class Forum
- 48 LFS242 Class Forum
- 38 LFS243 Class Forum
- 15 LFS244 Class Forum
- 5 LFS245 Class Forum
- LFS246 Class Forum
- LFS248 Class Forum
- 52 LFS250 Class Forum
- 2 LFS250-JP クラス フォーラム
- 1 LFS251 Class Forum
- 156 LFS253 Class Forum
- 1 LFS254 Class Forum
- 1 LFS255 Class Forum
- 9 LFS256 Class Forum
- 1 LFS257 Class Forum
- 1.3K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 131 LFS260 Class Forum
- 160 LFS261 Class Forum
- 43 LFS262 Class Forum
- 82 LFS263 Class Forum - Discontinued
- 15 LFS264 Class Forum - Discontinued
- 11 LFS266 Class Forum - Discontinued
- 24 LFS267 Class Forum
- 25 LFS268 Class Forum
- 32 LFS269 Class Forum
- 6 LFS270 Class Forum
- 202 LFS272 Class Forum - Discontinued
- 2 LFS272-JP クラス フォーラム
- 4 LFS147 Class Forum
- 1 LFS274 Class Forum
- 4 LFS281 Class Forum
- 12 LFW111 Class Forum
- 262 LFW211 Class Forum
- 184 LFW212 Class Forum
- 15 SKF100 Class Forum
- 1 SKF200 Class Forum
- 1 SKF201 Class Forum
- 797 Hardware
- 199 Drivers
- 68 I/O Devices
- 37 Monitors
- 104 Multimedia
- 174 Networking
- 91 Printers & Scanners
- 85 Storage
- 759 Linux Distributions
- 82 Debian
- 67 Fedora
- 17 Linux Mint
- 13 Mageia
- 23 openSUSE
- 148 Red Hat Enterprise
- 31 Slackware
- 13 SUSE Enterprise
- 354 Ubuntu
- 470 Linux System Administration
- 39 Cloud Computing
- 71 Command Line/Scripting
- Github systems admin projects
- 95 Linux Security
- 78 Network Management
- 102 System Management
- 47 Web Management
- 69 Mobile Computing
- 18 Android
- 38 Development
- 1.2K New to Linux
- 1K Getting Started with Linux
- 374 Off Topic
- 115 Introductions
- 174 Small Talk
- 24 Study Material
- 807 Programming and Development
- 304 Kernel Development
- 485 Software Development
- 1.8K Software
- 263 Applications
- 183 Command Line
- 3 Compiling/Installing
- 987 Games
- 317 Installation
- 102 All In Program
- 102 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)