linux-toradex.git/arch/um/Makefile, branch v4.4.26

arch: um: fix error when linking vmlinux.

2015-12-08T21:25:13+00:00

On gcc Ubuntu 4.8.4-2ubuntu1~14.04, linking vmlinux fails with:

arch/um/os-Linux/built-in.o: In function `os_timer_create':
/android/kernel/android/arch/um/os-Linux/time.c:51: undefined reference to `timer_create'
arch/um/os-Linux/built-in.o: In function `os_timer_set_interval':
/android/kernel/android/arch/um/os-Linux/time.c:84: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_remain':
/android/kernel/android/arch/um/os-Linux/time.c:109: undefined reference to `timer_gettime'
arch/um/os-Linux/built-in.o: In function `os_timer_one_shot':
/android/kernel/android/arch/um/os-Linux/time.c:132: undefined reference to `timer_settime'
arch/um/os-Linux/built-in.o: In function `os_timer_disable':
/android/kernel/android/arch/um/os-Linux/time.c:145: undefined reference to `timer_settime'

This is because -lrt appears in the generated link commandline
after arch/um/os-Linux/built-in.o. Fix this by removing -lrt from
arch/um/Makefile and adding it to the UM-specific section of
scripts/link-vmlinux.sh.

Signed-off-by: Lorenzo Colitti 
Signed-off-by: Richard Weinberger

um: Switch clocksource to hrtimers

2015-11-06T21:54:49+00:00

UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.

This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.

Fixes:
 - crashes when hosts suspends/resumes
 - broken userspace timers - effecive ~40Hz instead
   of what they should be. Note - this modifies skas behavior
   by no longer setting an itimer per clone(). Timer events
   are relayed instead.
 - kernel network packet scheduling disciplines
 - tcp behaviour especially under load
 - various timer related corner cases

Finally, overall responsiveness of userspace is better.

Signed-off-by: Thomas Meyer 
Signed-off-by: Anton Ivanov 
[rw: massaged commit message]
Signed-off-by: Richard Weinberger

um: Fix out-of-tree build

2015-10-19T20:53:36+00:00

Commit 30b11ee9a (um: Remove copy&paste code from init.h)
uncovered an issue wrt. out-of-tree builds.
For out-of-tree builds, we must not rely on relative paths.
Before 30b11ee9a it worked by chance as no host code included
generated header files.

Acked-by: Randy Dunlap 
Signed-off-by: Richard Weinberger

um: Stop abusing KERNEL

2015-05-31T20:05:32+00:00

Currently UML is abusing __KERNEL__ to distinguish between
kernel and host code (os-Linux). It is better to use a custom
define such that existing users of __KERNEL__ don't get confused.

Signed-off-by: Richard Weinberger

kbuild: use relative path more to include Makefile

2015-04-02T14:42:08+00:00

Prior to this commit, it was impossible to use relative path to
include Makefiles from the top level Makefile because the option
"--include-dir=$(srctree)" becomes effective when Make enters into
sub Makefiles.

To use relative path in any places, this commit moves the option
above the "sub-make" target.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Michal Marek

um: Fix for relative objtree when generating x86 headers

2014-06-05T15:55:48+00:00

In an O= build, rely on the generated Makefile to call the main Makefile
properly. When building in the source tree, we do not need to specify
the -C and O= either. This fixes the problem when $(objtree) is a
relative path and the -C changes the directory.

Reported-by: Richard Weinberger 
Signed-off-by: Michal Marek

um: Build always with -mcmodel=large on 64bit

2013-12-01T12:06:51+00:00

On UML SUBARCH can be x86, x86_64 and i386 and if it is x86
we use uname -m to select a defconfig.
Therefore we can no longer use -mcmodel=large only if SUBARCH
is x86_64.

Reported-and-tested-by: Boaz Harrosh 
Signed-off-by: Richard Weinberger

arch/um: make it work with defconfig and x86_64

2013-11-17T10:31:48+00:00

arch/um/defconfig only lists one default configuration, and that applies
only to the i386 architecture.  Replace it with two minimal
configuration files generated using `make savedefconfig`:

  i386_defconfig and x86_64_defconfig

The build scripts now require two updates:

1. um's Kconfig (arch/x86/um/Kconfig) should specify an ARCH_DEFCONFIG
   section explicitly pointing to these scripts if the required
   variables are set.  Take care to remove the DEFCONFIG_LIST section
   defined in the included file arch/um/Kconfig.common.

2. um's Makefile (arch/um/Makefile) should set KBUILD_DEFCONFIG properly
   for the top-level Makefile to pick up.  Copy the logic in
   arch/x86/Makefile to properly pick the defconfig file depending on
   the actual architecture; except we're working with $SUBARCH here,
   instead of $ARCH.

Now, you can do:

  $ ARCH=um make defconfig
  $ ARCH=um make

and successfully build User-Mode Linux on an x86_64 box in default
configuration.

Cc: Richard Weinberger 
Cc: Jeff Dike 
Signed-off-by: Ramkumar Ramachandra 
Signed-off-by: Richard Weinberger

UAPI: Partition the header include path sets and add uapi/ header directories

2012-10-02T17:01:26+00:00

Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.

Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.

The userspace set (represented by the USERINCLUDE make variable) contains:

	-I $(srctree)/arch/$(hdr-arch)/include/uapi
	-I arch/$(hdr-arch)/include/generated/uapi
	-I $(srctree)/include/uapi
	-I include/generated/uapi
	-include $(srctree)/include/linux/kconfig.h

and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:

	-I $(srctree)/arch/$(hdr-arch)/include
	-I arch/$(hdr-arch)/include/generated
	-I $(srctree)/include
	-I include		--- if not building in the source tree

plus everything in the USERINCLUDE set.

Then use USERINCLUDE in building the x86 boot code.

Signed-off-by: David Howells 
Acked-by: Arnd Bergmann 
Acked-by: Thomas Gleixner 
Acked-by: Paul E. McKenney 
Acked-by: Dave Jones

kbuild: link of vmlinux moved to a script

2012-05-05T19:19:33+00:00

Move the final link of vmlinux to a script to improve
readability and maintainability of the code.

The Makefile fragments used to link vmlinux has over the
years seen far too many changes and the logic had become
hard to follow.

As the process by nature is serialized there was
nothing gained including this in the Makefile.

"um" has special link requirments - and the
only way to handle this was to hard-code the linking
of "um" in the script.
This was better than trying to modularize it only for the
benefit of "um" anyway.

The shell script has been improved after input from:
Arnaud Lacombe 
Nick Bowler 

Signed-off-by: Sam Ravnborg 
Cc: Arnaud Lacombe 
Cc: Nick Bowler 
Cc: Richard Weinberger 
Signed-off-by: Michal Marek