Date: Mon, 22 Apr 2002 07:53:10 +0100 From: David Malone <dwmalone@maths.tcd.ie> To: acpi-jp@jp.FreeBSD.org, current@freebsd.org Subject: Odd problem with MTRR and ACPI Message-ID: <200204220753.aa19942@salmon.maths.tcd.ie>
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I have an ASUS A7A266 motherboard with an Athlon XP processor which seems prone to weirdness. The BIOS seems to set the MTRRs to some undocumented values, which used to prevent X starting. I've now fixed the MTRR code and X works fine. Unfortunately, when X changes the MTRRs then ACPI stops working. I tracked this down and found that the ACPI data just vanishes out of memory when you change the MTRRs! (Illustration included below, including hexdump of the bits of memory in question.) Has anyone seen anything like this? Does anyone have any idea what the old MTRR values mean? They are changed from 0x10(=???) to 0x01(=write-combine). David. MSR 26e, old=0x1010101010101010 new=0x0101010101010101 MSR 26f, old=0x1010101010101010 new=0x0101010101010101 gonzo 3 # acpidump | head -3 Found sig at f78c0 Checksum OK at f78c0 /* RSD PTR: Checksum=144, OEMID=ASUS, RsdtAddress=0x17fec000 */ gonzo 4# dd if=/dev/mem bs=1024 count=1024 | hd -s 0xf78c0 000f78c0 52 53 44 20 50 54 52 20 90 41 53 55 53 20 20 00 |RSD PTR .ASUS .| 000f78d0 00 c0 fe 17 00 c0 fe 17 40 c0 fe 17 80 c0 fe 17 |........@.......| 000f78e0 00 c1 fe 17 00 f0 ff 17 00 00 00 00 00 00 00 00 |................| 000f78f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000f8000 90 90 90 90 90 90 90 90 e9 41 61 2e 8b c0 8b c0 |.........Aa.....| <snipped binary data, which looks like it might be bios continues up to 1M> 00100000 gonzo 5# memcontrol set -b 983040 -l 65536 -o XFree86 write-combine gonzo 6# acpidump | head -3 acpidump: Can't find ACPI information gonzo 7# dd if=/dev/mem bs=1024 count=1024 | hd -s 0xf78c0 000f78c0 0c 00 04 00 00 40 f0 17 01 00 00 00 0b 80 00 00 |.....@..........| * 000fc240 0c 00 04 00 00 40 f0 17 01 00 00 00 00 00 00 00 |.....@..........| 000fc250 0c 00 00 00 00 08 3e ca 01 00 00 00 00 00 00 00 |......>.........| * 00100000 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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