[ARM] 4137/1: Add kexec support

Add kexec support to ARM.

Improvements like commandline handling could be made but this patch gives
basic functional support. It uses the next available syscall number, 347.

Once the syscall number is known, userspace support will be
finalised/submitted to kexec-tools, various patches already exist.

Originally based on a patch by Maxim Syrchin but updated and forward
ported by various people.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6783c2e5512d..a8298949d166 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -738,6 +738,20 @@ config XIP_PHYS_ADDR
           be linked for and stored to.  This address is dependent on your
           own flash usage.
 
+config KEXEC
+        bool "Kexec system call (EXPERIMENTAL)"
+        depends on EXPERIMENTAL
+        help
+          kexec is a system call that implements the ability to shutdown your
+          current kernel, and to start another kernel.  It is like a reboot
+          but it is indepedent of the system firmware.   And like a reboot
+          you can start any kernel with it, not just Linux.
+
+          It is an ongoing process to be certain the hardware in a machine
+          is properly shutdown, so do not be surprised if this code does not
+          initially work for you.  It may help to enable device hotplugging
+          support.
+
 endmenu
 
 if (ARCH_SA1100 || ARCH_INTEGRATOR || ARCH_OMAP || ARCH_IMX )