How do I build the 4.1.15 kernel with FrameBuffer support?

[michaelworster]

I was using the latest imx_4.1.15_1.0.0_ga kernel branch and attempting to do a build using the imx_v6_v7_defconfig. Once I attempted to build the zImage target the build broke due to missing FB references. Below is a snippet of the process I used to get the code and build the defconfig/kernel

mike@mike-VirtualBox:~/fsl_test/kernel4$ git clone git://git.freescale.com/imx/linux-2.6-imx.git --branch imx_4.1.15_1.0.0_ga

mike@mike-VirtualBox:~/fsl_test/kernel4$ make O=/home/mike/fsl_test/k4_output/ imx_v6_v7_defconfig
make[1]: Entering directory `/home/mike/fsl_test/k4_output'
  HOSTCC  scripts/basic/fixdep
  GEN     ./Makefile
  HOSTCC  scripts/kconfig/conf.o
  SHIPPED scripts/kconfig/zconf.tab.c
  SHIPPED scripts/kconfig/zconf.lex.c
  SHIPPED scripts/kconfig/zconf.hash.c
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#
make[1]: Leaving directory `/home/mike/fsl_test/k4_output'
mike@mike-VirtualBox:~/fsl_test/kernel4$ make O=/home/mike/fsl_test/k4_output/ zImage LOADADDR=0x10008000
make[1]: Entering directory `/home/mike/fsl_test/k4_output'
  GEN     ./Makefile
scripts/kconfig/conf  --silentoldconfig Kconfig
make[1]: Leaving directory `/home/mike/fsl_test/k4_output'
make[1]: Entering directory `/home/mike/fsl_test/k4_output'
  CHK     include/config/kernel.release

...

  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o

drivers/built-in.o: In function `mxsfb_probe':
:(.text+0x45f4c): undefined reference to `mxc_dispdrv_gethandle'
make[1]: *** [vmlinux] Error 1

I've found that the missing reference comes from drivers/video/fbdev/mxc/mxc_dispdrv.c and can be added in by including:

CONFIG_FB_MXC_SYNC_PANEL=y

to the defconfig, once that is in place there are additional build issues that show up:

drivers/built-in.o: In function `mxcfb_blank':
:(.text+0x43674): undefined reference to `ipu_disable_channel'
:(.text+0x43688): undefined reference to `ipu_uninit_sync_panel'
:(.text+0x43694): undefined reference to `ipu_uninit_channel'
...

Which can be fixed by adding in:
CONFIG_MXC_IPU_V3=y

Once that is added there is a new problem, as both drivers/mxc/ipu3/ipu_capture.c and drivers/gpu/ipu-v3/ipu-csi.c include the same "exports" and thus there is a multiple definition issue:

drivers/mxc/built-in.o: In function `ipu_csi_init_interface':
:(.text+0x12f18): multiple definition of `ipu_csi_init_interface'
drivers/gpu/built-in.o::(.text+0x3a4fc): first defined here
drivers/mxc/built-in.o:(___ksymtab+ipu_csi_init_interface+0x0): multiple definition of `__ksymtab_ipu_csi_init_interface'
drivers/gpu/built-in.o:(___ksymtab_gpl+ipu_csi_init_interface+0x0): first defined here
drivers/mxc/built-in.o: In function `__crc_ipu_csi_init_interface':

... (A number of these)

(One example:)

drivers/mxc/ipu3/ipu_capture.c:ipu_csi_init_interface(struct ipu_soc *ipu, uint16_t width, uint16_t height,
drivers/mxc/ipu3/ipu_capture.c:EXPORT_SYMBOL(ipu_csi_init_interface);
drivers/gpu/ipu-v3/ipu-csi.c:int ipu_csi_init_interface(struct ipu_csi *csi,
drivers/gpu/ipu-v3/ipu-csi.c:EXPORT_SYMBOL_GPL(ipu_csi_init_interface);

So my question becomes:

How can I do a standard Linux Kernel 4.1.15 build with the imx_v6_v7_defconfig which includes Framebuffer support? Seems either I'm missing something, or there is something wrong with this config.

[michaelworster · Accepted solution]

gusarambula‌ - Thanks for your reply. I was indeed attempting to build on the 4.1.15_1.0.0_ga branch, and previously building the 3.14.38 kernel both in and without OpenEmbedded. The OpenEmbedded build takes more space and time so I try to avoid it for initial development. Your answer, however, did lead me to a thought which solved the problem.

It turns out that the answer to my question is that imx_v6_v7_defconfig doesn't work correctly with the Linux 4.1.15 kernel. When I built with OpenEmbedded the kernel succeeded but checking the logs for the kernel it was obvious what the difference was:

run.do_copy_defconfig.31634:    cp /home/mike/sandbox/nxp_linux_4.15/build_k4_linux/tmp/work/imx6dlsabresd-poky-linux-gnueabi/linux-imx/4.1.15-r0/git/arch/arm/configs/imx_v7_defconfig /home/mike/sandbox/nxp_linux_4.15/build_k4_linux/tmp/work/imx6dlsabresd-poky-linux-gnueabi/linux-imx/4.1.15-r0/build/.config

imx_v6_v7_defconfig, which I was using for a imx6dlsabresd build on the 3.14.38 kernel is no longer used, it is now replaced with the imx_v7_defconfig. When I replace my build steps with the same set but this different defconfig everything works.

[gusarambula]

Hello Michael Worster,

The easiest way to achieve this would be trough Yocto.

Have you used the 4.1.15_1.0.0_ga BSP Release? You can find the documentation on the link below (please note that you may need to login in order to download this file).

https://www.nxp.com/webapp/Download?colCode=L4.1.15_1.0.0_LINUX_DOCS&Parent_nodeId=13376371545356958...

Please look at the Yocto Project User’s Guide to install the required packages to run Yocto.

On Step 5 you can see how to setup for your board and also for the distro you would like to use. In your case fsl-imx-fb, which would be frame buffer graphics with no X11 or Wayland.

If you wish to build only the kernel you may also do to from within Yocto using the linux-imx recipe:

$ bitbake linux-imx

I hope this information helps!

Regards,