> > For i386/amd64 you have to tell boot you want serial output > > either at the boot prompt or via boot.conf. > > > > stty com0 115200 > > set tty com0 > > > OpenBSD 5.8 (GENERIC.MP) #1236: Sun Aug 16 02:31:04 MDT 2015 > dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP > RTC BIOS diagnostic error > ff<clock_battery,ROM_cksum,config_unit,memory_size,fixed_disk,invalid_time> > real mem = 4246003712 (4049MB) > avail mem = 4113428480 (3922MB) > mpath0 at root > scsibus0 at mpath0: 256 targets > mainbus0 at root > bios0 at mainbus0: SMBIOS rev. 2.7 @ 0xdf16d820 (7 entries) > bios0: vendor coreboot version "4.0" date 09/08/2014 > bios0: PC Engines APU > acpi0 at bios0: rev 0 > acpi0: sleep states S0 S1 S3 S4 S5 > acpi0: tables DSDT FACP SPCR HPET APIC HEST SSDT SSDT SSDT
Since the ACPI BIOS provides a SPCR table, we can actually tell that we're on a serial console. Shouldn't be too difficult to add support to the kernel for this, although we'd probably miss the first part of the dmesg if we do that. So a better place would be the bootloader, but then we'd have to add code to find and parse acpi tables there. And there might be space issues there.
