I have the 7ULL module and I made some tests with the new yocto release Y1.0 specially with CAN interface. I didn't build the yocto from source but I directly tested the f&s compiled version in "binaries" folder after I extracted "fsimx6ul-Y1.0.tar.bz2"
In this "binaries" folder there are many files, I copied them to FAT formated USB stick and only renamed the following files so that the names match the environement variables that will be set by the install.scr file.
* uImage-fsimx6ul-Y1.0 --> uImage-fsimx6ul
* install-fsimx6ul-Y1.0.scr --> install.scr
* fus-image-std-x11-fsimx6ul-Y1.0.ubifs --> rootfs-fsimx6ul.ubifs
* efusa7ull-Y1.0.dtb --> efusa7ull.dtb
I erased the nand flash on the 7Ull module and installed new uboot version from the same "binaries" folder, exactly this one "uboot-fsimx6ul-Y1.0.nb0". After that I inserted the USB stick on the development boad then it started writing the ubifs to the nand and I can login normally.
I brought CAN0 interface up using "ip link set can0 up type can bitrate 125000" then I used PCAN adapter to test the communication between the development board and the adapter.
1- Transmission from PC over PCAN adapter to the development board:
running the following on the serial console on the development board receives all messages correctly when they sent from the PC side.
2- Transmission from development board to PC over PCAN adapter
when sending this frame from the development board over the CAN bus using -->
it will not be correctly received on the PC side in the PCAN View window. !!
PLEASE note when I perform the same test exactly as in 1 and 2 for those binaries of the buildroot method, then this problem does not show up again. This leaves no doubt that the CAN drivers used in yocto sources are somehow different from that of buildroot method.
I attached also a photo of the received frame on the PCAN view whe transmitted from the development board.