no serial console for ttyd0 HP Blade

[Jo Rhett]

On Jul 2, 2008, at 1:04 AM, Marian Hettwer wrote:
> puuuh, well, with your suggested change, I do get a login prompt now  
> (at
> ttyd1 it says), but I don't see any bootup messages anymore.
> It seems that the sio0 is irq 4 while booting and becomes irq3 later.
> That's odd.
> If I remember correctly, one was able to configure the mapping of  
> serial
> ports in the BIOS (in regards to those HP blades). Perhaps that helps.
> I'll give it a shot and if I found a way to have boot messages and the
> login getty, I'll drop a [solved] mail to this list.

So the boot loader uses 0x3f8 irq 4 no matter what it's mapped to.
Second stage does something similar, but
After you've loaded the kernel it does mappings to sio0 and sio1 and  
these may be different.
This is why you have to screw with device.hints so that all three  
stages are using the same device.

> Jul  1 15:13:57 db46-202 kernel: sio0: <Standard PC COM port> port  
> 0x2f8-0x2ff irq 3 flags 0x10 on acpi0


It's pretty clear from your grep command that sio0 is 0x2f8 irq 3, but  
the boot loader always uses 0x3f8 irq 4.  You have to change these  
until the device which has 0x3f8 irq 4 has the "flags 0x10" option,  
which is what makes it the console.

NOTE: I think this whole parade sucks, and the kernel should believe  
device.hints ... but there is no apparent interest in solving this  
problem (even when a bounty is offered), and I don't do enough device  
driver development these days for it to be worth my time.

-- 
Jo Rhett
Net Consonance : consonant endings by net philanthropy, open source  
and other randomness