> I'm trying to write an IDE driver with busmaster DMA support. > My problem is that I can't get the right controller registers addresses. > > In the IDE BusMaster DMA specification : > > "The control registers for the controller are allocated via the > devices Base Address register at offset 0x20 in PCI configuration > space." > > If I read the word at offset 0x20 in the PCI configuration space, I get > 0xc001. But if I boot qemu with a linux live-cd, it tells me that BM-DMA > is at 0xc000 > > Do I have to init the PCI IDE controller or something ?
Bit 0 encodes if the registers are in IO (1) or in memory (0) space. You get the IO base address by using a 0xfffffffe mask. For memory space the mask is 0xfffffff0, the low four bits encode a few memory properties (prefetch, 32-bit vs. 64-bit memory addresses). See the PCI spec for more details. Or for example the PCI_BASE_* defines here: http://cvs.opensolaris.org/source/xref/usr/src/uts/common/sys/pci.h#519 _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel
