Date: Mon, 16 Dec 1996 13:19:33 -0800 From: "Jin Guojun[ITG]" <jin@george.lbl.gov> To: erich@lodgenet.com Cc: hackers@freebsd.org Subject: Re: Q for loadable network driver Message-ID: <199612162119.NAA29129@george.lbl.gov>
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Another question is that is necessary to link the newly loaded driver to
the kernel control block --
/sys/pci.c:155:static struct pcicb *pcicb;
-------------------------------------------------------------
pci/pci.c: unmodified: line 704 --
/*
** allocate bus descriptor for bus behind the bridge
*/
link = &pcicb->pcicb_down;
while (*link && (*link)->pcicb_bus < secondary)
link = &(*link)->pcicb_next;
this = malloc (sizeof (*this), M_DEVBUF, M_WAITOK);
... ...
/*
** Link it in chain.
*/
*link=this;
pci/pci.c: unmodified: line 819 --
-----------------------------------------------------------------
Without an interface to get the PCI control block address -- &pcicb -- it is
hardly to link the new information into the kernel PCI chain.
Also, is the segment above (pci/pci.c line 704 - 819) necessary for loading
a loadable device driver?
Thanks for any information,
-Jin
}>I have a question in writing a loadable network driver.
}>How is the PCI device table is load into pcidevice_set list --
}> pcidevice_set.ls_items
}
}it's a linker set, see the archives for Terry's good explanation
}of what these are and how they work.
}
}>That is, what is the mechanism to replace these lines :
}>
}>struct pci_device xyz_device = {
}> OEM_DRVNAME,
}> xyz_probe,
}> xyz_attach,
}> &xyz_count,
}> xyz_shutdown
}>};
}>
}>DATA_SET(pcidevice_set, xyz_device);
}
}I believe that they're only used during the autoconf phase of
}the pci bus. The pci subsystem gets a signature of all devices
}on the bus; then asks each driver in the pcidevice_set, `hey
}is this your device?' by calling the probe/attach members.
}
}I think they can savely be #ifdef'ed out for the lkm case, because
}you're not autoconf'ing. Then lkm equivalent is done in the
}xyz_load call. You might be able to peruse a pci data structure that
}has a list of `found but not claimed' devices where you should find
}your device's signature, or you may be able to play with /usr/bin/pciconf
}to determine if your device exists before attempting the modload.
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