1b02a38329
This replaces the somewhat opaque preprocessor based stack/unstack macros with open coded ldp/stp sequences to preserve the interrupted context before handing over to the exception handler in C. This removes various arithmetic operations on the stack pointer, and reduces the exception return critical section to its minimum size (i.e., the bare minimum required to populate the ELR and SPSR registers and invoke the eret). Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org> Reviewed-by: Eugene Cohen <eugene@hp.com>