Question

Hi,

I have the latest teltonika firmware for RUT955: RUT9_R_00.07.01.2. 

I tried to install kmod-video-uvc, but i got the following error:

root@Teltonika-RUT955:/# opkg install kmod-video-uvc
Unknown package 'kmod-video-uvc'.
Collected errors:
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-nls-base
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-usb-core
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-dma-buf
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-dma-buf found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-i2c-core
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-video-core
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-core found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-video-videobuf2
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-videobuf2 found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-input-core
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-input-core found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-video-uvc
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-uvc found, but incompatible with the architectures configured
* opkg_install_cmd: Cannot install package kmod-video-uvc.

So i downloaded the SDK and compiled the package/kernel/linux with VIDEO UVC selected from a make menuconfig run. 

And tried to install my built kmod-video-uvc and got:

root@Teltonika-RUT955:/tmp/kernelz# opkg install kmod-video-uvc_5.4.147-1_mips_24kc.ipk  
Unknown package 'kmod-video-uvc'.
Collected errors:
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-nls-base
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-usb-core
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-dma-buf
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-dma-buf found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-i2c-core
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-video-core
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-core found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-video-videobuf2
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-videobuf2 found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-79c5dc6db69102eb2943a96b9bec8b63) for kmod-input-core
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-input-core found, but incompatible with the architectures configured
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.147-1-unknown) for kmod-video-uvc
* pkg_hash_fetch_best_installation_candidate: Packages for kmod-video-uvc found, but incompatible with the architectures configured
* opkg_install_cmd: Cannot install package kmod-video-uvc.

Anyone have any ideas why the pre-built kmod packages dossen't work with the firmware provided by teltonika and why the custom build package with the correct SDK dossen't work, i know i have the right version of the SDK since i use it to build other custom packages.

Any help or pointers would be appreciated!

Answer 1

Hello,

When you install your custom built kernel module via opkg install, make sure it takes the correct ipk not the one from the opkg update list. For that, execute rm /tmp/opkg-list/* and retry.

Regards,

Comments

I manually extracted and modules.d files and lib/modules files and made a list to keep track of them.

Now i get this at boot:

[   27.294359] videobuf2_memops: Unknown symbol put_vaddr_frames (err -2)
[   27.301427] videobuf2_memops: Unknown symbol get_vaddr_frames (err -2)
[   27.308450] videobuf2_memops: Unknown symbol frame_vector_destroy (err -2)
[   27.315814] videobuf2_memops: Unknown symbol frame_vector_create (err -2)
[   27.388114] kmodloader: 3 modules could not be probed
[   27.404200] kmodloader: dependency not loaded videobuf2-vmalloc
[   27.428669] kmodloader: - uvcvideo - 1
[   27.436653] kmodloader: - videobuf2-memops - 0
[   27.456668] kmodloader: dependency not loaded videobuf2-memops
[   27.472709] kmodloader: - videobuf2-vmalloc - 1
 

Seems like something is broken!, checking online it seems like the kernel needs to be configured with some option FRAME_VECTOR, how can i do this IF it is the source of the issue?

From some mailinglist:

diff --git a/mm/Kconfig b/mm/Kconfig
index 9b8fccb969dc..cfa6a80d1a0a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -701,7 +701,7 @@  config ZONE_DEVICE
          If FS_DAX is enabled, then say Y.

 config FRAME_VECTOR
-       bool
+       tristate "frame vector"

 config ARCH_USES_HIGH_VMA_FLAGS
        bool

All files shows up as loaded in when issuing lsmod, it seems like somthing else is missing in the kernel.

---

I finally fixed it, it turns out your kernel need to be built with the option above if the videobuf2_memops is to be loaded as a module.

So i just flashed the modem with my own image (so that i get the custom kernel).

Now the everyting works verified on the modem and webcam works fine, i can take my pictures.

Thanks to Flebourse for all the help!

R.

---

Turns out there was two issues, the .143 to .147 subversion and kernel hash one, and the FRAME_VECTOR one. So forcing the kernel hash was doomed anyway due to the second.

Where did you put the patch ?

---

Never put the patch anywhere, never used it, instead i run make menuconfig and selected the kernelmodules -> video (all modules) to include in image so (*) instead of (M). ran make -j10 -k after that and flashed the router with the generated image, after modem reboot it all worked, detection of USB camera and taking a picture periodically worked fine.

But i guess you can go to build_dir/target-mips.../linux-ath79_generic/linux-5.4.147/mm/Kconfig and apply the patch to that Kconfig or just change the affected line from "bool" to: { tristate "frame vector" } as mentioned above, but i never tried it, however the pro with having a kernel installed with the patch is that you could build ipks modulary {M} and your custom modules should be able to find the kernel address space even if you load them after boot a.k.a. loading a .ko file with "insmod". But as i said i never tried it just builded them into kernel with {*}, and flashed.

R.

---

I have added it to target/linux/ath79/patches-5.4/950-mm-tristate-frame-vector.pach to be immune to a make clean.

Btw, kudos for your RS485 comment.