Hello,
I'm currently developing a bootloader for a MPC8548 based board. This board has
got three PCI interfaces (PCI1, PCI2 and PCIe). At the PCIe interface the
MPC8548 appears as PCI-Bridge (at bus 0 device 0), at the PCI1/2 interfaces the
MPC8548 appears as normal devices (bus 0 device 0).
And now I'm a little bit unshure about how Linux expects the PCI bus mapping. I
see two ways:
A)
--------
MPC8548: PCI1 PCI2 PCIe
| | |
| | 3
| | bridge
0 2 4
-------- | | |
extern: ------- ------ ------
| | | | | | |
dev | dev dev dev... dev dev ...
0
bridge
1
|
---------
| | |
dev dev dev...
Since I have to create Type 0 Config Read/Writes to access the first bus of an
interface, my PciConfigRead/Write functions would have to convert the bus no.
from 0->0 2->0 3->0 (for the example). And PCIe bridge's primary bus no. has to
be set to 0.
or B)
--------
MPC8548: PCI1 PCI2 PCIe
| | |
| | 0
| | bridge
0 0 1
-------- | | |
extern: ------- ------ ------
| | | | | | |
dev | dev dev dev... dev dev ...
0
bridge
1
|
---------
| | |
dev dev dev...
Every bus is mapped independently. And PciConfigRead/Write functions convert
the bus no. so that upper layers (and user) see a bus mapping similar to A).
Maybe someone knows how U-Boot or Linux would map the interfaces?
Thank you for your Help.
Ralf
Best Regards/Mit freundlichen Gruessen
Ralf Trübenbach, Software Design
MEN Mikro Elektronik GmbH
Neuwieder Straße 5-7
90411 Nuremberg, Germany
Phone +49-911-99 33 5-0
Fax +49-911-99 33 5-910
E-Mail [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
www.men.de <http://www.men.de/>
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