arm: provide a PCS-compliant setjmp implementation
The previous setjmp-implementation (as a static inline function that
contained an 'asm volatile' sequence) was extremely fragile: (some
versions of) GCC optimised the set of registers. One critical example
was the removal of 'r9' from the clobber list, if -ffixed-reg9 was
supplied.
To increase robustness and ensure PCS-compliant behaviour, the setjmp
and longjmp implementation are now in assembly and closely match what
one would expect to find in a libc implementation.
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Tested-by: Andy Yan <andy.yan@rock-chips.com>
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 6e1c436..abffa10 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -17,6 +17,12 @@
obj-y += vectors.o crt0.o
endif
+ifdef CONFIG_ARM64
+obj-y += setjmp_aarch64.o
+else
+obj-y += setjmp.o
+endif
+
ifndef CONFIG_SPL_BUILD
ifdef CONFIG_ARM64
obj-y += relocate_64.o