From: Christophe Lyon <[email protected]> rt==15 is a special case when reading the flags: it means the destination is APSR. This patch avoids rejecting vmrs apsr_nzcv, fpscr as illegal instruction.
Cc: [email protected] Signed-off-by: Christophe Lyon <[email protected]> Message-id: [email protected] [PMM: updated the comment] Reviewed-by: Peter Maydell <[email protected]> Signed-off-by: Peter Maydell <[email protected]> (cherry picked from commit 2529ab43b8a05534494704e803e0332d111d8b91) Signed-off-by: Michael Roth <[email protected]> --- target/arm/translate-vfp.inc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/target/arm/translate-vfp.inc.c b/target/arm/translate-vfp.inc.c index ef45cecbea..75406fd9db 100644 --- a/target/arm/translate-vfp.inc.c +++ b/target/arm/translate-vfp.inc.c @@ -704,9 +704,10 @@ static bool trans_VMSR_VMRS(DisasContext *s, arg_VMSR_VMRS *a) if (arm_dc_feature(s, ARM_FEATURE_M)) { /* * The only M-profile VFP vmrs/vmsr sysreg is FPSCR. - * Writes to R15 are UNPREDICTABLE; we choose to undef. + * Accesses to R15 are UNPREDICTABLE; we choose to undef. + * (FPSCR -> r15 is a special case which writes to the PSR flags.) */ - if (a->rt == 15 || a->reg != ARM_VFP_FPSCR) { + if (a->rt == 15 && (!a->l || a->reg != ARM_VFP_FPSCR)) { return false; } } -- 2.17.1
