[PATCH] kexec: x86_64: add CONFIG_PHYSICAL_START
For one kernel to report a crash another kernel has created we need
to have 2 kernels loaded simultaneously in memory. To accomplish this
the two kernels need to built to run at different physical addresses.
This patch adds the CONFIG_PHYSICAL_START option to the x86_64 kernel
so we can do just that. You need to know what you are doing and
the ramifications are before changing this value, and most users
won't care so I have made it depend on CONFIG_EMBEDDED
bzImage kernels will work and run at a different address when compiled
with this option but they will still load at 1MB. If you need a kernel
loaded at a different address as well you need to boot a vmlinux.
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index a853d87..56c02cf 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -369,6 +369,17 @@
Additional support for intel specific MCE features such as
the thermal monitor.
+config PHYSICAL_START
+ hex "Physical address where the kernel is loaded" if EMBEDDED
+ default "0x100000"
+ help
+ This gives the physical address where the kernel is loaded.
+ Primarily used in the case of kexec on panic where the
+ fail safe kernel needs to run at a different address than
+ the panic-ed kernel.
+
+ Don't change this unless you know what you are doing.
+
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
depends on PROC_FS