I am running the latest Raspbian build (Buster). I have compiled a kernel with audit/apparmor support and am trying to boot my Raspberry Pi 4 from it. The kernel is compiled from the latest branch cloned from the GitHub repository. This is resulting in a repeated error during boot:
[x.xxxxxx] raspberrypi-firmware soc:firmware: Coherent DMA mask 0xffffffff (pfn 0xfff40000-0x40000) covers a smaller range of system memory than the DMA zone pfn 0x0-0x80001
I also get other errors I do not understand the cause of:
[x.xxxxxx] bcm2835-cpureq:bcm2835_cpufreq_get_clock:93: Failed to get clock (-12)
[x.xxxxxx] bcm2835_cpufreq: min=0 max=0
[x.xxxxxx] raspberrypi-exp-gpio soc:firmware:gpio: Failed to get GPIO 2 config (-12 82)
[x.xxxxxx] leds-gpio: probe of leds failed with error -12
It ends up hanging after just over a total of 3 seconds into boot with the error:
[x.xxxxxx] Waiting for root device /dev/mmcblk0p2...
What can cause these type of errors?