Messages in this thread | | | Date | Wed, 2 Jun 2010 13:31:29 -0700 | Subject | Re: How to tell kernel that a region of memory is reserved (in middle of ram)? | From | Yinghai Lu <> |
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On Wed, Jun 2, 2010 at 3:11 AM, Maxim Levitsky <maximlevitsky@gmail.com> wrote: > Hi, > > I need to reserve a region of ram to store there a ramoops buffer. > I need to do so early so kernel doesn't overwrite the existing contents. > > How to do it? > > I noticed that doing memmap=20M$0x70000000 crashes the system although > it promised to work. > Is that a bug? > > I have 2GB system with following memory map: > > [ 0.000000] BIOS-provided physical RAM map: > [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) > [ 0.000000] BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) > [ 0.000000] BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) > [ 0.000000] BIOS-e820: 0000000000100000 - 000000007fcfd000 (usable) > [ 0.000000] BIOS-e820: 000000007fcfd000 - 000000007fd08000 (reserved) > [ 0.000000] BIOS-e820: 000000007fd08000 - 000000007fd52000 (usable) > [ 0.000000] BIOS-e820: 000000007fd52000 - 000000007fd55000 (reserved) > [ 0.000000] BIOS-e820: 000000007fd55000 - 000000007fdbb000 (usable) > [ 0.000000] BIOS-e820: 000000007fdbb000 - 000000007fdbf000 (reserved) > [ 0.000000] BIOS-e820: 000000007fdbf000 - 000000007fe70000 (usable) > [ 0.000000] BIOS-e820: 000000007fe70000 - 000000007febf000 (ACPI NVS) > [ 0.000000] BIOS-e820: 000000007febf000 - 000000007ff00000 (ACPI data) > [ 0.000000] BIOS-e820: 000000007ff00000 - 0000000080000000 (reserved) > [ 0.000000] BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) > [ 0.000000] BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved) > [ 0.000000] BIOS-e820: 00000000fed14000 - 00000000fed1a000 (reserved) > [ 0.000000] BIOS-e820: 00000000fed1c000 - 00000000fed20000 (reserved) > [ 0.000000] BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved) > [ 0.000000] BIOS-e820: 00000000fff00000 - 0000000100000000 (reserved) >
kernel version?
you could boot with "debug earlyprintk=ttyS0,115200" to get more info.
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