Using an MCIMX6ULL-EVK,
I have been trying to get my build system working with the end goal adding spidev to the linux userspace.
With the first step of simply compiling Linux on my system and verify that the board can boot correctly.
However, the kernels and SD card images my system is producing are not working. I don't know what the kernel is doing because it doesn't print to the terminal. It could be in an infinite loop for all I know.
Description of my process:
Using the provided SD card, pre-flashed with distribution 4.9.88_2.0.0, the board boots up correctly and I can log in over serial.
I have been approaching this problem from two directions:
1. Recompiling Linux with the appropriate imx_v6_v7_defconfig, and dropping the resulting zImage onto the SD card. Note that the Linux kernel is v5.15.31, and the corresponding SDK environment used to build Linux is 5.15-kirkstone.
However, once I power on the system, U-boot reads and starts the new kernel. But that's the end of that since I it never prints any more output afterwards.
2. Recompiling the whole system using Yocto using:
bitbake core-image-minimal
And either dropping the resulting zImage onto the SD card, or writing the whole core-image-base-imx6ulevk.wic to another SD card, in which case, the system performs an endless reboot loop. Producing this output:
CPU: Commercial temperature grade (0C to 95C) at 42C
Reset cause: POR
Model: Freescale i.MX6 UltraLite 14x14 EVK Board
Board: MX6UL 14x14 EVK
DRAM: 512 MiB
Core: 63 devices, 18 uclasses, devicetree: separate
MMC: FSL_SDHC: 0, FSL_SDHC: 1
Loading Environment from MMC... *** Warning - bad CRC, using default environment
[*]-Video Link 0 (480 x 272)
[0] lcdif@21c8000, video
In: serial
Out: serial
Err: serial
data abort
pc : [<9eea1e2a>] lr : [<9eec0a51>]
reloc pc : [<87823e2a>] lr : [<87842a51>]
sp : 9de748a0 ip : 9de7488c fp : 87800020
r10: 00000017 r9 : 9de7bec0 r8 : 00000100
r7 : 021bc400 r6 : 9eecd9e5 r5 : 00000000 r4 : 9de7e9d0
r3 : ffffffff r2 : 02140000 r1 : 00006cc8 r0 : ffffffff
Flags: NzCv IRQs off FIQs off Mode SVC_32 (T)
Code: 1e03 9300 da0e 6822 (6853) b125
Resetting CPU ...
resetting ...
When I drop the new Yocto zImage onto the SD card like I did for the linux kernel only compilation, It stops printing after U-boot jumps into the kernel just like in the first scenario I listed above.
