On Dec 21, 2007 1:40 PM, Corey Osgood corey.osgood@gmail.com wrote:
aaron lwe wrote:
Dear All,
I'm terribly sorry that I just found I've mistakenly configured the dram MA Map Type, and now memtest showed no errors. But I still have to reduce the mem size when reporting to system through ram_resource or filo couldn't be started. I have disabled the integrated graphics card and the agp, so I don't think the top memory should be reserved for frame buffer.
And now you're where I am. For some reason there's a reserved memory range _somewhere_ at the tolm, of some unknown size. I've found that reserving an extra 1MB doesn't work, but 32MB does. I've found nothing in the documentation I have to explain this. BTW, have you had to make any code changes other than the MA Map, and board-specific fixes? I'm wondering how generic that code really is.
-Corey
From what you have said, I guess it might be AGP aperture memory
that caused this problem. I saw you allocated 32MB for agp aperture memory in agp.c, so reserving 32MB works for you, and I changed this to 128MB for agp aperture memory so 128MB works for me. The problem is why this agp aperture memory is at physical memory range (tolm - agp_aperture_size to tolm) while we have set this agp aperture memory base at some very large address(e.g 0xe0000000). should this memory range be assigned a mtrr?
The changes I made to your code are : 1) some registers in host bus, as their values are different from the factory BIOS ones; 2) dram size releated registers 3) dram timing is ok. and I found couldn't change dram operating frequency ;-(