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authorJan H. Schönherr <jschoenh@amazon.de>2018-02-03 00:10:20 +0100
committerIngo Molnar <mingo@kernel.org>2018-02-26 08:44:52 +0100
commitef61f8a340fd6d49df6b367785743febc47320c1 (patch)
tree010e1943bd46fcc03e8d5ddb638c0e81254a9a5b /Documentation/admin-guide
parent672c0ae09b33a11d8f31fc61526632e96301164c (diff)
downloadlinux-ef61f8a340fd6d49df6b367785743febc47320c1.tar.bz2
x86/boot/e820: Implement a range manipulation operator
Add a more versatile memmap= operator, which -- in addition to all the things that were possible before -- allows you to: - redeclare existing ranges -- before, you were limited to adding ranges; - drop any range -- like a mem= for any location; - use any e820 memory type -- not just some predefined ones. The syntax is: memmap=<size>%<offset>-<oldtype>+<newtype> Size and offset work as usual. The "-<oldtype>" and "+<newtype>" are optional and their existence determine the behavior: The command works on the specified range of memory limited to type <oldtype> (if specified). This memory is then configured to show up as <newtype>. If <newtype> is not specified, the memory is removed from the e820 map. Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180202231020.15608-1-jschoenh@amazon.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1d1d53f85ddd..5529fa82700b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2237,6 +2237,15 @@
The memory region may be marked as e820 type 12 (0xc)
and is NVDIMM or ADR memory.
+ memmap=<size>%<offset>-<oldtype>+<newtype>
+ [KNL,ACPI] Convert memory within the specified region
+ from <oldtype> to <newtype>. If "-<oldtype>" is left
+ out, the whole region will be marked as <newtype>,
+ even if previously unavailable. If "+<newtype>" is left
+ out, matching memory will be removed. Types are
+ specified as e820 types, e.g., 1 = RAM, 2 = reserved,
+ 3 = ACPI, 12 = PRAM.
+
memory_corruption_check=0/1 [X86]
Some BIOSes seem to corrupt the first 64k of
memory when doing things like suspend/resume.