Michel
Wed May 07 04:30:56 PDT 2008
No, of course it does not fail. What happens is this:
BIOS: CE
COM1 3F8 COM1 3F8
COM2 2F8 COM2 2F8
COM3 3E8 COM3 3E8
COM4 2E8 COM4 2E8
Now we change the BIOS:
BIOS CE
COM1 2E8 COM4 2E8
COM2 3E8 COM3 3E8
COM3 2F8 COM2 2F8
COM4 3F8 COM1 3F8
So, all you did is route *BIOS* COM1 to *CE* COM4. There's no way CE
"knows" about the *name* you assigned to an address in the BIOS. All you
did was change the addresses and CE just loads whatever name you give in
CE to that base address.
Good luck,
Michel Verhagen, eMVP
Check out my blog:
http://GuruCE.com/blog
GuruCE Ltd.
Microsoft Embedded Partner
http://GuruCE.com
Consultancy, training and development services.
Rick wrote:
> The port I verified is COM2. It is working well with IOBase 2F8 always.
> Then, in BIOS SETUP menu, I try to adjust the COM2 IO to 3F8.
> Right now, COM2 is 3F8 IObase at this x86 board.
> Next step, use original NK image (with COM2 2F8 IOBase in platform.reg) ,
> the COM2 still works by new BIOS setting.
> The same image actually works well, whenever what IObase of COM2 I modified
> in BIOS setup. 3F8, 2F8 and 2E8 are fit the same image.
> I think COM2 should be failed when IO resource changed in BIOS SETUP.
> But, Not this result.
>
> Rick
>
> "Luca Calligaris" wrote:
>
>> The usual configuration for serial ports in the PC BIOS is:
>>
>> COM1 3F8 / IRQ 4
>> COM2 2F8 / IRQ 3
>>
>> Take in account that Windows CE may use the first port (3F8/4) for debug; in
>> the CEPC registry, you would see:
>>
>> [HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Serial]
>> "SysIntr"=dword:13
>> "IoBase"=dword:02F8
>>
>> This means that what you see in Windows CE as "COM1:" will be the BIOS COM2.
>> Maybe the serial port that you are modifying in the BIOS is not the one
>> corresponding to your
>> registry entry
>>
>>
>>
>> --
>>
>> Luca Calligaris
>> www.eurotech.it
>>
>> "Rick" <Rick@discussions.microsoft.com> ha scritto nel messaggio
>> news:9C830583-9AEB-48F4-8A3A-5D0F4B5D9402@microsoft.com...
>>> Hi,
>>> I test WinCE5.0 at x86 platform. One strange thing in serial port confused
>>> me.
>>> Per my past experience , serial driver get IoBase address according to the
>>> IoBase value in platform.reg.
>>>
>>> [HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Serial2]
>>> "SysIntr"=dword:14
>>> "IoBase"=dword:02F8
>>>
>>> But, when I adjust IO address of COM2 to 3F8h (another value) in BIOS
>>> setup,
>>> COM2 still can work. Right now, the IoBase in BIOS setup conflicts with
>>> IoBase value in platform.reg. I didn't modify platform.reg.
>>>
>>> Why serial port can work well ?
>>>
>>> thanks
>>> Rick
>>>
>>>
>>
>>