diff options
| -rw-r--r-- | target/arm/translate.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c index 4ea4018e2b..a978453506 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3513,12 +3513,27 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) } } } else { /* !dp */ + bool is_sysreg; + if ((insn & 0x6f) != 0x00) return 1; rn = VFP_SREG_N(insn); + + is_sysreg = extract32(insn, 21, 1); + + 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. + */ + if (is_sysreg && (rd == 15 || (rn >> 1) != ARM_VFP_FPSCR)) { + return 1; + } + } + if (insn & ARM_CP_RW_BIT) { /* vfp->arm */ - if (insn & (1 << 21)) { + if (is_sysreg) { /* system register */ rn >>= 1; @@ -3585,7 +3600,7 @@ static int disas_vfp_insn(DisasContext *s, uint32_t insn) } } else { /* arm->vfp */ - if (insn & (1 << 21)) { + if (is_sysreg) { rn >>= 1; /* system register */ switch (rn) { |