LDP
/
man-pages
mirror of https://github.com/mkerrisk/man-pages
0
1
Fork 0
Code Releases Activity

bootparam.7: Remove crufty "mem=" details 

The information here relates to ancient systems
Some (possibly more up to date) info can be found
in Documentation/kernel-parameters.txt.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Michael Kerrisk 2015-04-24 11:03:50 +02:00
parent af26ce0fab
commit 2e10d8f65e
1 changed files with 0 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
man7/bootparam.7
View File

@ -278,43 +278,6 @@ reserve=0x300,32 blah=0x300
keeps all device drivers except the driver for 'blah' from probing
0x300\-0x31f.
.TP
.B "'mem=...'"
The BIOS call defined in the PC specification that returns
the amount of installed memory was designed only to be able
to report up to 64MB.
Linux uses this BIOS call at boot to
determine how much memory is installed.
If you have more than 64MB of
RAM installed, you can use this boot argument to tell Linux how much memory
you have.
The value is in decimal or hexadecimal (prefix 0x),
and the suffixes 'k' (times 1024) or 'M' (times 1048576) can be used.
Here is a quote from Linus on usage of the 'mem=' parameter.
.in +0.5i
The kernel will accept any 'mem=xx' parameter you give it, and if it
turns out that you lied to it, it will crash horribly sooner or later.
The parameter indicates the highest addressable RAM address, so
\&'mem=0x1000000' means you have 16MB of memory, for example.
For a 96MB machine this would be 'mem=0x6000000'.
.BR NOTE :
some machines might use the top of memory for BIOS
caching or whatever, so you might not actually have up to the full
96MB addressable.
The reverse is also true: some chipsets will map
the physical memory that is covered by the BIOS area into the area
just past the top of memory, so the top-of-mem might actually be 96MB
+ 384kB for example.
If you tell linux that it has more memory than
it actually does have, bad things will happen: maybe not at once, but
surely eventually.
.in
You can also use the boot argument 'mem=nopentium' to turn off 4 MB
page tables on kernels configured for IA32 systems with a pentium or newer
CPU.
.TP
.B "'panic=N'"
By default, the kernel will not reboot after a panic, but this option
will cause a kernel reboot after N seconds (if N is greater than zero).