On 2013-08-23, Hugo Osvaldo Barrera <h...@osvaldobarrera.com.ar> wrote: > Hi! > I've started managing a serial server through a serial console, and have > come into some unusual issues. > I followed the instrucitons on faq 7.7, and also configured by BIOS > accordingly. > > When I conect my PC to the server, I see BIOS and POST output properly, > I then see the OpenBSD bootloader properly, and all the kernel messages come > out fine (ie: the white-on-blue text), however, AFTER the kernel messages, > I only see the following sixteen characters and nothing else (though > later kernel messages like plugging in a USB are shown properly). > > In single user mode, this would be: > "Enter pathname o" > > In non-single user mode, this would be > "Automatic boot i" > > It's extremely odd. I'm cleary not having cable issues, wrong rates, > or anything alike, because I'm seeing kernel output just fine.
This is exactly what you would see if the IRQ assignment is wrong. There are other possibilities too, but this is easy to check in the BIOS, and is a somewhat likely problem. The first port (known as com0 in OpenBSD, com1 in MSDOS) should be at 0x3f8 irq 4, the second should be 0x2f8 irq 3. Sometimes vendors (I've seen it with Jetway) have been known to screw up and reverse the irq assignments. Some other OS take these from ISAPNP but OpenBSD hardcodes the standard values for a PC-compatible machine and expects the port to be there. > com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo > com0: console > com1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
