tree 603302f37d76a3e3a20ebfa01bfba45e6273caaf
parent 5636d4a7b9c3f6ada659b3a037e52dee1f5c9a4c
author Philipp Tomsich <philipp.tomsich@theobroma-systems.com> 1507645273 +0200
committer Philipp Tomsich <philipp.tomsich@theobroma-systems.com> 1511305042 +0100

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>