2001-02-24 20:28:24 +00:00
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Setting up MTRR for X11 or mga_vid:
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===================================
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1. find the base address
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~~~~~~~~~~~~~~~~~~~~~~~~
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2001-03-12 14:56:55 +00:00
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You have 3 ways to find it:
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2001-02-24 20:28:24 +00:00
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- from X11 startup messages, for example:
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(--) SVGA: PCI: Matrox MGA G400 AGP rev 4, Memory @ 0xd8000000, 0xd4000000
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(--) SVGA: Linear framebuffer at 0xD8000000
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- from /proc/pci (use lspci -v command):
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01:00.0 VGA compatible controller: Matrox Graphics, Inc.: Unknown device 0525
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Memory at d8000000 (32-bit, prefetchable)
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- from mga_vid kernel driver messages (use dmesg):
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mga_mem_base = d8000000
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2. find memory size
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~~~~~~~~~~~~~~~~~~~
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2001-03-12 14:56:55 +00:00
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This is very easy, just convert video ram size to hexadecimal, or
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2001-02-24 20:28:24 +00:00
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use this table:
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1 MB 0x100000
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2 MB 0x200000
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4 MB 0x400000
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8 MB 0x800000
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16 MB 0x1000000
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32 MB 0x2000000
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3. setting up mtrr
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~~~~~~~~~~~~~~~~~~
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You know base address and memory size, let's setup mtrr registers!
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For example, for the matrox card above (base=0xd8000000) with 32MB
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ram (size=0x2000000) just execute:
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echo "base=0xd8000000 size=0x2000000 type=write-combining" >| /proc/mtrr
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2001-03-12 14:56:55 +00:00
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- Older K6-2's [around 266Mhz, stepping 0] doesn't support MTRR.
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- K6-2 with 'stepping 12' (do a cat /proc/cpuinfo) supports MTRR.
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