On 09/22/2017 10:59 AM, Peter Maydell wrote: > In the v7M architecture, there is an invariant that if the CPU is > in Handler mode then the CONTROL.SPSEL bit cannot be nonzero. > This in turn means that the current stack pointer is always > indicated by CONTROL.SPSEL, even though Handler mode always uses > the Main stack pointer. > > In v8M, this invariant is removed, and CONTROL.SPSEL may now > be nonzero in Handler mode (though Handler mode still always > uses the Main stack pointer). In preparation for this change, > change how we handle this bit: rename switch_v7m_sp() to > the now more accurate write_v7m_control_spsel(), and make it > check both the handler mode state and the SPSEL bit. > > Note that this implicitly changes the point at which we switch > active SP on exception exit from before we pop the exception > frame to after it. > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > --- > target/arm/cpu.h | 8 ++++++- > hw/intc/armv7m_nvic.c | 2 +- > target/arm/helper.c | 65 > ++++++++++++++++++++++++++++++++++----------------- > 3 files changed, 51 insertions(+), 24 deletions(-)
Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
