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| author | Peter Maydell <peter.maydell@linaro.org> | 2017-03-20 12:41:44 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2017-03-20 12:41:44 +0000 |
| commit | 43ac65742319ef5ac4461daf43316b189cd21e89 (patch) | |
| tree | 002d91e680d68c84c9583073482b75adb38b02fb /target/arm/translate.c | |
| parent | 001b3cab51ebfcb13e8dd03ea25bfa3bd0c517a3 (diff) | |
| download | qemu-43ac65742319ef5ac4461daf43316b189cd21e89.zip | |
arm: Don't decode MRS(banked) or MSR(banked) for M profile
M profile doesn't have the MSR(banked) and MRS(banked) instructions
and uses the encodings for different kinds of M-profile MRS/MSR.
Guard the relevant bits of the decode logic to make sure we don't
accidentally fall into them by accident on M-profile.
(The bit being checked for this (bit 5) is part of the SYSm field on
M-profile, but since no currently allocated system registers have
encodings with bit 5 of SYSm set, this hasn't been a problem in
practice.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1487616072-9226-3-git-send-email-peter.maydell@linaro.org
Diffstat (limited to 'target/arm/translate.c')
| -rw-r--r-- | target/arm/translate.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c index 216852b673..a5f5a28ba4 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -10500,7 +10500,8 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw gen_exception_return(s, tmp); break; case 6: /* MRS */ - if (extract32(insn, 5, 1)) { + if (extract32(insn, 5, 1) && + !arm_dc_feature(s, ARM_FEATURE_M)) { /* MRS (banked) */ int sysm = extract32(insn, 16, 4) | (extract32(insn, 4, 1) << 4); @@ -10521,7 +10522,8 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw store_reg(s, rd, tmp); break; case 7: /* MRS */ - if (extract32(insn, 5, 1)) { + if (extract32(insn, 5, 1) && + !arm_dc_feature(s, ARM_FEATURE_M)) { /* MRS (banked) */ int sysm = extract32(insn, 16, 4) | (extract32(insn, 4, 1) << 4); |