On Tue, Oct 20, 2015 at 02:12:35PM +0200, Mark Kettenis wrote: > > > 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. >
Interesting. On a dell server from 2007 booted via glass console the table is present with the address and baud set to 0. I guess that changes if I were to configure the bios to put the console on serial. On the other hand I have a machine from 2009 that only has serial and there is no SPCR table "acpi0: tables DSDT FACP APIC MCFG HPET". It seems there can be a DBGP/DBG2 table in some cases that indicates if debug ports are available on serial/firewire/usb/network as well. [028h 0040 12] Serial Port Register : [Generic Address Structure] [028h 0040 1] Space ID : 00 [SystemMemory] [029h 0041 1] Bit Width : 00 [02Ah 0042 1] Bit Offset : 00 [02Bh 0043 1] Encoded Access Width : 00 [Undefined/Legacy] [02Ch 0044 8] Address : 0000000000000000 [034h 0052 1] Interrupt Type : 03 [035h 0053 1] PCAT-compatible IRQ : 04 [036h 0054 4] Interrupt : 00000004 [03Ah 0058 1] Baud Rate : 00 [03Bh 0059 1] Parity : 00 [03Ch 0060 1] Stop Bits : 01 [03Dh 0061 1] Flow Control : 02 [03Eh 0062 1] Terminal Type : 01 [04Ch 0076 1] Reserved : 00 [040h 0064 2] PCI Device ID : FFFF [042h 0066 2] PCI Vendor ID : FFFF [044h 0068 1] PCI Bus : 00 [045h 0069 1] PCI Device : 00 [046h 0070 1] PCI Function : 00 [047h 0071 4] PCI Flags : 00000000 [04Bh 0075 1] PCI Segment : 00 [04Ch 0076 4] Reserved : 00000000
