PEX 8111 PCI-Express to PCI Bridge and FreeBSD

Konstantin Dimitrov kosio.dimitrov at
Thu Dec 27 05:44:47 PST 2007

hello All,

as far as i understand the documentation of the PEX 8111 PCI
Express-to-PCI Bridge, which is freely available here:

it is "Fully Transparent PCI Express to PCI Bridge", but under FreeBSD
it doesn't seem to behave as transparent, i.e. it doesn't seem to work
well with the standard FreeBSD PCI-PCI bridge driver, because it's not
possible to read/write from/to the PCI IC behind PEX 8111.

i've tried PEX 8111 on vanilla WinXP (i.e. without any updates), that
is 6-7 years old and thus made 3-4 years before even PEX 8111 existed
and indeed it is transparent and doesn't require special drivers,
works with the standard WinXP PCI-PCI bridge driver pci.sys and also
it is possible to read/write from/to the PCI IC behind the PEX 8111,
then made the same test under latest Debian GNU/Linux and again it
works as transparent bridge and it is possible to read/write from/to
the PCI IC behind the PEX 8111, without any special driver for the

here is the real life situation, that i'm talking about:

i am in possession of S010-V PCI-E audio card:

actually, S010-V uses PEX 8111 bridge to place Envy24HT PCI audio
controller on the PCI-E bus.

i'm testing with very simple code, that makes dump of the Envy24HT EEPROM:

that code works well and it is tested under FreeBSD with more than 10
Envy24HT PCI cards, but it doesn't work under FreeBSD with the S010-V
PCI-E card, the same code ported to Windows, as i mentioned above,
works with S010-V PCI-E card and same apply to Linux.

so, my kind request is someone to help me to resolve the issue.

i'm suspecting that something is wrong with the FreeBSD PCI-PCI bridge
driver, because only under FreeBSD, PEX 8111 doesn't behave as
transparent bridge, but maybe i'm wrong.

if someone want to look at the problem, i can give remote access to
the machine with the S010-V PCI-E card.

thank you and best wishes,

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