Hi, I want to install the latest OpenBSD on a Mac mini, but the kernel fails with a panic. Everything was fine with OpenBSD 5.9 before.
Since version 6.0, OpenBSD is unable to boot on a Mac mini (2014 model = MacMini7,1). On amd64, I'm getting the following kernel panic with using 6.0, 6.1 and 6.2: avail mem = 4017737728 (3831MB) mainbus0 at root bios0 at mainbus0: SMBIOS rev. 2.4 @ 0x88d10000 (49 entries) bios0: vendor Apple Inc. bios0: Apple Inc Macmini7,1 acpi0 at bios0: rev2 [..] cpu0: Intel(R) Core(TM) i5-4260U CPU @ 1.40GHz, 2000.26 MHz [..] cpu at mainbus0: not configured ioapic0 at mainbus0: apid 2 pa 0xfec00000, version 20, 40 pins acpiec0 at acpi0 Unsupported RegionSpace 0x5 panic: aml_die aml_rwfield:2493 The operating system has halted. Press press any key to reboot. rebooting... This has also been reported by Bryan Vyhmeister over a year ago! https://marc.info/?l=openbsd-misc&m=146714369624842&w=4 So I'm wondering why nobody noticed that before... The kernel panic is caused in line 2493 in sys/dev/acpi/dsdt.c. (https://github.com/openbsd/src/blob/master/sys/dev/acpi/dsdt.c) The only difference in the code between OpenBSD 5.0 and 6.0 was a change in the default CASE, where aml_rwgas(ref1, fld->v_field.bitpos + bpos, blen, val, mode, fld->v_field.flags); was done before. Doing machine memory at the boot> prompt of the install62.fs, I can see the memory regions: [..] Region 4: type 1 at 0x90000 for 64KB Region 5: type 1 at 0x100000 for 2240576KB Region 6: type 1 at 0x88d10000 for 268KB [...] Low ram: 640KB High ram: 2352128KB Total free memory: 4067512KB I'm planning to boot the Mac mini with an external hd and custom-built kernel to see whether a change in the code will fix the problem for me. Please not that I do not have access to a running OpenBSD on the Mac mini right now... In the meantime it would be great if you could acknowledge the problem and propse a fix or at least some instructions how I could get the Mac mini booting again! PS: I also CC'ed Bryan as he might provide further help. Best wishes, *Kristian
