Hi, I am trying to fix a kernel panic I am seeing on my vim3 board (Amlogic A311D). I don't have enough knowledge about this area, but my current guess is the kernel is using a piece of memory belonging to ARM-trusted firmware that I shouldn't. Log: [ 9.792966] SError Interrupt on CPU3, code 0x00000000bf000000 -- SError [ 9.792980] CPU: 3 PID: 3471 Comm: kded5 Tainted: G C 6.2.0 #1 [ 9.792985] Hardware name: Khadas VIM3 (DT) [ 9.792987] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 9.792991] pc : kmem_cache_free_bulk.part.98+0x1f0/0x528 [ 9.793004] lr : kmem_cache_free_bulk.part.98+0x2f8/0x528 [ 9.793008] sp : ffff80000a2eb7f0 [ 9.793009] x29: ffff80000a2eb7f0 x28: ffff00001f358518 x27: ffff000000008800 [ 9.793016] x26: ffff00000262b300 x25: ffff00000262b300 x24: 0000000000000001 [ 9.793019] x23: ffff00000262b000 x22: 0000000000000000 x21: ffff00001f358538 [ 9.793022] x20: fffffc0000098ac0 x19: 0000000000000004 x18: 0000000000000040 [ 9.793025] x17: 0000000000000018 x16: 00000000000007f8 x15: 0000000000000003 [ 9.793028] x14: 0000000000000006 x13: ffff800008e48550 x12: 0000ffff9dc91fff [ 9.793031] x11: 0000000000000004 x10: 0000000000000001 x9 : ffff000007e93680 [ 9.793035] x8 : 0000000000000020 x7 : ffff000001d2b100 x6 : 0000000000000007 [ 9.793037] x5 : 0000000000000020 x4 : ffff000000008800 x3 : 0000000000000001 [ 9.793040] x2 : 0000000000000007 x1 : 0000000000000000 x0 : ffff00001f358540 [ 9.793045] Kernel panic - not syncing: Asynchronous SError Interrupt This doesn't happen with downstream Khadas 6.2 kernel, and that's because the downstream kernel removed this from early_init_dt_reserve_memory (drivers/of/fdt.c): /* * If the memory is already reserved (by another region), we * should not allow it to be marked nomap, but don't worry * if the region isn't memory as it won't be mapped. */ if (memblock_overlaps_region(&memblock.memory, base, size) && memblock_is_region_reserved(base, size)) return -EBUSY; And this causes 3 MiB of memory belonging to ARM Trusted firmware to be reserved. arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi : /* 3 MiB reserved for ARM Trusted Firmware (BL31) */ secmon_reserved: secmon@5000000 { reg = <0x0 0x05000000 0x0 0x300000>; no-map; }; And the mainline kernel fails to reserve that memory: [ 0.000000] OF: fdt: Reserved memory: failed to reserve memory for node 'secmon@5000000': base 0x0000000005000000, size 3 MiB It fails to reserve because memblock_overlaps_region and memblock_is_region_reserved return one. I think memblock_is_region_reserved is saying the memory is already reserved by uboot and shouldn't be nomap, but it should. Is there a bug here? Why the kernel is failing to reserve this memory? Is this an u-boot issue? I would appreciate any help. The current mainline kernel fails 90% of the time to boot into the Vim3 board. Best Regards Lucas Tanure