Hi, I used the same strategy, but had similar issues. So I just skip the first couple of 1000 bytes. I'd like to find out why too. Also, memory wraps. If I have 32MB of RAM @ 0x80000000, then run the memory test in non-existent memory from 0x82000000 to 0x83ffffff it appears to reference 0x80000000 to 0x81ffffff. Can this be made to fail? Lyle > -----Original Message----- > From: linux-mips-bounce@linux-mips.org > [mailto:linux-mips-bounce@linux-mips.org] On Behalf Of Jeff Baitis > Sent: Wednesday, May 14, 2003 5:27 PM > To: linux-mips@linux-mips.org > Subject: Power On Self Test and testing memory > > > Hi all: > > I implemented memory tests in my bootloader code for the > AU1500. I'm trying to figure out why Linux boots when loaded > into cached KSEG0 (0x 80c0 0000), but my memory test FAILS > for this same region. > > (pretty backwards huh? get linux booting, then write memory tests!) > > > I start by writing 0x5555 5555 to all of uncached memory, > reading it back, and I write 0xAAAA AAAA to all of uncached > memory and read it back. > > This works great. > > Next, I try to write 0x5555 5555 to cached KSEG0 memory, and > it fails at addr 0x8000FE50. But Linux boots! > > I'm not issuing SYNC commands when writing to cached memory; > could this be the problem? > > We've exhaustively verified the memory burst parameters, etc. > They look good. > > Thank you in advance for your ideas! > > Regards, > Jeff > > -- > Jeffrey Baitis - Associate Software Engineer > > Evolution Robotics, Inc. > 130 West Union Street > Pasadena CA 91103 > > tel: 626.535.2776 | fax: 626.535.2777 | baitisj@evolution.com >
