Hi Kent, I have been following the instructions as directed - https://docs.sel4.systems/Hardware/imx8mm.html Without the change to disable KernelAArch64SErrorIgnore this is the output I get on my imx8mm-evk board Bootstrapping kernel available phys memory regions: 2 [40000000..b8000000] [b8400000..c0000000] reserved virt address space regions: 3 [ffffff8040000000..ffffff804023f000] [ffffff804023f000..ffffff804024a000] [ffffff804024a000..ffffff8040651000] Booting all finished, dropped to user space Node 0 of 1 IOPT levels: 0 IPC buffer: 0x807000 Empty slots: [1118 --> 8192) sharedFrames: [0 --> 0) userImageFrames: [30 --> 1061) userImagePaging: [14 --> 19) untypeds: [1061 --> 1118) Initial thread domain: 0 Initial thread cnode size: 13 List of untypeds ------------------ Paddr | Size | Device 0 | 29 | 1 0x20000000 | 28 | 1 0x30000000 | 27 | 1 0x38000000 | 23 | 1 0x38810000 | 16 | 1 0x38820000 | 17 | 1 0x38840000 | 18 | 1 0x38940000 | 18 | 1 0x38980000 | 19 | 1 0x38a00000 | 21 | 1 0x38c00000 | 22 | 1 0x39000000 | 24 | 1 0x3a000000 | 25 | 1 0x3c000000 | 26 | 1 0xb8000000 | 22 | 1 0xc0000000 | 30 | 1 0x100000000 | 32 | 1 0x200000000 | 33 | 1 0x400000000 | 34 | 1 0x800000000 | 35 | 1 0x1000000000 | 36 | 1 0x2000000000 | 37 | 1 0x4000000000 | 38 | 1 0x8000000000 | 39 | 1 0x40000000 | 16 | 0 0x40651000 | 12 | 0 0x40652000 | 13 | 0 0x40654000 | 14 | 0 0x40658000 | 15 | 0 0x40660000 | 17 | 0 0x40680000 | 19 | 0 0x40700000 | 20 | 0 0x40800000 | 23 | 0 0x41000000 | 24 | 0 0x42000000 | 25 | 0 0x44000000 | 26 | 0 0x48000000 | 27 | 0 0x50000000 | 28 | 0 0x60000000 | 29 | 0 0x80000000 | 29 | 0 0xa0000000 | 28 | 0 0xb0000000 | 27 | 0 0xb8400000 | 22 | 0 0xb8800000 | 23 | 0 0xb9000000 | 24 | 0 0xba000000 | 25 | 0 0xbc000000 | 25 | 0 0xbe000000 | 24 | 0 0xbf000000 | 23 | 0 0xbf800000 | 22 | 0 0xbfc00000 | 21 | 0 0xbfe00000 | 20 | 0 0xbff00000 | 19 | 0 0xbffd9800 | 11 | 0 0xbffda000 | 13 | 0 0xbffdc000 | 14 | 0 0xbffe0000 | 17 | 0 Untyped summary 1 untypeds of size 11 1 untypeds of size 12 2 untypeds of size 13 2 untypeds of size 14 1 untypeds of size 15 2 untypeds of size 16 3 untypeds of size 17 2 untypeds of size 18 3 untypeds of size 19 2 untypeds of size 20 2 untypeds of size 21 4 untypeds of size 22 4 untypeds of size 23 4 untypeds of size 24 4 untypeds of size 25 2 untypeds of size 26 3 untypeds of size 27 3 untypeds of size 28 3 untypeds of size 29 1 untypeds of size 30 1 untypeds of size 32 1 untypeds of size 33 1 untypeds of size 34 1 untypeds of size 35 1 untypeds of size 36 1 untypeds of size 37 1 untypeds of size 38 1 untypeds of size 39 Switching to a safer, bigger stack... seL4 Test ========= vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 2147483648, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 1073741824, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 536870912, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 268435456, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 134217728, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 67108864, error 1 vka_alloc_object_at_maybe_dev@object.h:58 Failed to allocate object of size 33554432, error 1 halting... Kernel entry via Syscall, number: 1, Call Cap type: 2, Invocation tag: 1 I am building with this version of gcc should the problem be related to the version of toolchain. This is the aarch64 compiler we use on other projects for building U-Boot without any issues. aarch64-linux-gnu-gcc (Debian 8.3.0-2) 8.3.0 Copyright (C) 2018 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Cheers, Zippy