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PCI Bus Master on MIPS platform
Hi, I'm currently
writing a simple test to bus master graphic data from system memory to video
memory using ATI's graphic chip. I set the descriptor tables and data
in system memory using malloc and assert the correct graphic chip registers to
initaiate the bus master, but the data doesn't get transfered.
I enabled the Bus
master bit in the PCI config space header, it seems like the graphic chip
doesn't know where to fetch the data since the address provided by Malloc
functions return the virtual address, where the graphic chip is expecting the
physical address. I also tried hardcoding the physical address of
the NEC VR5000 chip into the registers but the data doesn't get
transferred, It works on a PC platform using DPMI functions which
translate logical to physical address. Is there some sort of similar
functions for the MIPS platform where I can allocate a pool of system memory
that maps virtual to physical address?.
Any help in this
area would do. Has anyone else tried to do a bus master on a MIPS platform
with similar graphic chip?