[PATCH v2 01/14] arch: introduce symbol HAVE_INITJMP

[Jerome Forissier]

HAVE_INIJMP will be set by architectures that support initjmp(), a
non-standard extension to setjmp()/longjmp() allowing to initialize a
jump buffer with a function pointer and a stack pointer. This will be
useful to later introduce threads. With this new function it becomes
possible to longjmp() to a particular function pointer (rather than
to a point previously reached during program execution as is the case
with setjmp()), and with a custom stack. Both things are needed to
spin off a new thread. Then the usual setjmp()/ longjmp() pair is
enough to save and restore a context, i.e., switch thread.

Signed-off-by: Jerome Forissier <jerome.forissier at linaro.org>
---
 arch/Kconfig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index 35b19f9bfdc..8d5b54031b3 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -13,6 +13,12 @@ config HAVE_SETJMP
 	help
 	 The architecture supports setjmp() and longjmp().
 
+config HAVE_INITJMP
+	bool
+	help
+	 The architecture supports initjmp(), a non-standard companion to
+	 setjmp() and longjmp().
+
 config SUPPORT_BIG_ENDIAN
 	bool
 
-- 
2.43.0