i386/100831: sio ignores BIOS information about serial ports - bounty offered

[Jo Rhett]

On Aug 4, 2006, at 5:29 AM, Bruce Evans wrote:
> It makes perfects sense when you understand that the unit number  
> may be
> assigned at many levels, starting with the BIOS.  Whether you can make
> COM1 be COM2 at the BIOS level depends on BIOS support for this.  I've

Sorry, saying nonsense like this confuses the issue.  COM1 is a CPM/ 
DOS designation that means 0x3f8 irq 4.

Saying COM1 = COM2 means "IO 0x3f8 irq 4 == 0x2f8 irq 3".  Can you  
understand that this makes no sense?

Physical port ordering has no meaning with regards to COM1 ports.   
Even on the original IBM hardware you could set jumpers and swap  
which physical port was COM1 and which was COM2.  I spent years doing  
this! :-)

-- 
Jo Rhett
senior geek
Silicon Valley Colocation