Correct me if wrong. On 10/1/08, yogeshwar sonawane <yogyas@xxxxxxxxx> wrote: > Hi all, > > By reading the PCI BAR value from PCI config space, one gets BAR > region starting address for that PCI device. > If device is 32-bit capable, then max 6 BARs are possible, but for > 64-bit PCI card, only 3 BAR regions are possible. > > Generally, BIOS sets the address/value in these BARs which device > driver reads & access the device. I am referring linux OS. > So the BAR region address range OR starting address assignment is done by > BIOS. > Can we change this address through device driver, by writing the PCI > BARs in PCI config space ? > There are apis to read/write to PCI config space. > > Can i map a BAR region of a PCI device, above 4 GB (i.e. 64-bit addr) > instead of 32bit address(higher 32bits as 0) ? > If possible, how to do this ? > Above 4GB, u need PAE + HIGHMEM option both enabled. Yes, u can always use kmap() and friends API to map from > 4GB area to lowmem. Then writing will just write to these lowmem area. Reference: http://www.ussg.indiana.edu/hypermail/linux/kernel/0806.3/1019.html Correct???? > Writing/changing BAR register value through device driver, will > propagate till PCI root controller ? > Can setpci command be used for this ? > > Any link or reference will be helpful. > > Thanking in advance, > Yogeshwar -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
