Enforce that for M-profile various FPSCR bits which are RES0 there
but have defined meanings on A-profile are never settable. This
ensures that M-profile code can't enable the A-profile behaviour
(notably vector length/stride handling) by accident.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id:
20190416125744.27770-2-peter.maydell@linaro.org
val &= ~FPCR_FZ16;
}
+ if (arm_feature(env, ARM_FEATURE_M)) {
+ /*
+ * M profile FPSCR is RES0 for the QC, STRIDE, FZ16, LEN bits
+ * and also for the trapped-exception-handling bits IxE.
+ */
+ val &= 0xf7c0009f;
+ }
+
/*
* We don't implement trapped exception handling, so the
* trap enable bits, IDE|IXE|UFE|OFE|DZE|IOE are all RAZ/WI (not RES0!)