linux/arch/um/Kconfig.um

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config STATIC_LINK
bool "Force a static link"
default n
help
This option gives you the ability to force a static link of UML.
Normally, UML is linked as a shared binary. This is inconvenient for
use in a chroot jail. So, if you intend to run UML inside a chroot,
you probably want to say Y here.
Additionally, this option enables using higher memory spaces (up to
2.75G) for UML.
source "mm/Kconfig"
config LD_SCRIPT_STATIC
bool
default y
uml: throw out CONFIG_MODE_TT This patchset throws out tt mode, which has been non-functional for a while. This is done in phases, interspersed with code cleanups on the affected files. The removal is done as follows: remove all code, config options, and files which depend on CONFIG_MODE_TT get rid of the CHOOSE_MODE macro, which decided whether to call tt-mode or skas-mode code, and replace invocations with their skas portions replace all now-trivial procedures with their skas equivalents There are now a bunch of now-redundant pieces of data structures, including mode-specific pieces of the thread structure, pt_regs, and mm_context. These are all replaced with their skas-specific contents. As part of the ongoing style compliance project, I made a style pass over all files that were changed. There are three such patches, one for each phase, covering the files affected by that phase but no later ones. I noticed that we weren't freeing the LDT state associated with a process when it exited, so that's fixed in one of the later patches. The last patch is a tidying patch which I've had for a while, but which caused inexplicable crashes under tt mode. Since that is no longer a problem, this can now go in. This patch: Start getting rid of tt mode support. This patch throws out CONFIG_MODE_TT and all config options, code, and files which depend on it. CONFIG_MODE_SKAS is gone and everything that depends on it is included unconditionally. The few changed lines are in re-written Kconfig help, lines which needed something skas-related removed from them, and a few more which weren't strictly deletions. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 10:26:50 +02:00
depends on STATIC_LINK
config LD_SCRIPT_DYN
bool
default y
depends on !LD_SCRIPT_STATIC
source "fs/Kconfig.binfmt"
config HOSTFS
tristate "Host filesystem"
help
While the User-Mode Linux port uses its own root file system for
booting and normal file access, this module lets the UML user
access files stored on the host. It does not require any
network connection between the Host and UML. An example use of
this might be:
mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
where /tmp/fromhost is an empty directory inside UML and
/tmp/umlshare is a directory on the host with files the UML user
wishes to access.
For more information, see
<http://user-mode-linux.sourceforge.net/hostfs.html>.
If you'd like to be able to work with files stored on the host,
say Y or M here; otherwise say N.
config HPPFS
tristate "HoneyPot ProcFS (EXPERIMENTAL)"
depends on EXPERIMENTAL && PROC_FS
help
hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
entries to be overridden, removed, or fabricated from the host.
Its purpose is to allow a UML to appear to be a physical machine
by removing or changing anything in /proc which gives away the
identity of a UML.
See <http://user-mode-linux.sf.net/old/hppfs.html> for more information.
You only need this if you are setting up a UML honeypot. Otherwise,
it is safe to say 'N' here.
config MCONSOLE
bool "Management console"
default y
help
The user mode linux management console is a low-level interface to
the kernel, somewhat like the i386 SysRq interface. Since there is
a full-blown operating system running under every user mode linux
instance, there is much greater flexibility possible than with the
SysRq mechanism.
If you answer 'Y' to this option, to use this feature, you need the
mconsole client (called uml_mconsole) which is present in CVS in
2.4.5-9um and later (path /tools/mconsole), and is also in the
distribution RPM package in 2.4.6 and later.
It is safe to say 'Y' here.
config MAGIC_SYSRQ
bool "Magic SysRq key"
depends on MCONSOLE
help
If you say Y here, you will have some control over the system even
if the system crashes for example during kernel debugging (e.g., you
will be able to flush the buffer cache to disk, reboot the system
immediately or dump some status information). A key for each of the
possible requests is provided.
This is the feature normally accomplished by pressing a key
while holding SysRq (Alt+PrintScreen).
On UML, this is accomplished by sending a "sysrq" command with
mconsole, followed by the letter for the requested command.
The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
unless you really know what this hack does.
config SMP
bool "Symmetric multi-processing support (EXPERIMENTAL)"
default n
depends on BROKEN
help
This option enables UML SMP support.
It is NOT related to having a real SMP box. Not directly, at least.
UML implements virtual SMP by allowing as many processes to run
simultaneously on the host as there are virtual processors configured.
Obviously, if the host is a uniprocessor, those processes will
timeshare, but, inside UML, will appear to be running simultaneously.
If the host is a multiprocessor, then UML processes may run
simultaneously, depending on the host scheduler.
This, however, is supported only in TT mode. So, if you use the SKAS
patch on your host, switching to TT mode and enabling SMP usually
gives you worse performances.
Also, since the support for SMP has been under-developed, there could
be some bugs being exposed by enabling SMP.
If you don't know what to do, say N.
config NR_CPUS
int "Maximum number of CPUs (2-32)"
range 2 32
depends on SMP
default "32"
config HIGHMEM
bool "Highmem support (EXPERIMENTAL)"
depends on !64BIT && BROKEN
default n
help
This was used to allow UML to run with big amounts of memory.
Currently it is unstable, so if unsure say N.
To use big amounts of memory, it is recommended enable static
linking (i.e. CONFIG_STATIC_LINK) - this should allow the
guest to use up to 2.75G of memory.
config KERNEL_STACK_ORDER
int "Kernel stack size order"
default 1 if 64BIT
range 1 10 if 64BIT
default 0 if !64BIT
help
This option determines the size of UML kernel stacks. They will
be 1 << order pages. The default is OK unless you're running Valgrind
on UML, in which case, set this to 3.
config MMAPPER
tristate "iomem emulation driver"
help
This driver allows a host file to be used as emulated IO memory inside
UML.
config NO_DMA
def_bool y