Support the "subs pc, lr" Thumb-2 exception return instruction.
Signed-off-by: Rabin Vincent <ra...@rab.in>
---
target-arm/translate.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 10a516b..f0667e5 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -8001,8 +8001,17 @@ static int disas_thumb2_insn(CPUState *env, DisasContext
*s, uint16_t insn_hw1)
gen_bx(s, tmp);
break;
case 5: /* Exception return. */
- /* Unpredictable in user mode. */
- goto illegal_op;
+ if (IS_USER(s)) {
+ goto illegal_op;
+ }
+
+ tmp = load_reg(s, rn);
+ tmp2 = new_tmp();
+ tcg_gen_movi_i32(tmp2, insn & 0xff);
+ gen_helper_sub_cc(tmp, tmp, tmp2);
+ gen_exception_return(s, tmp);
+ dead_tmp(tmp2);
+ break;
case 6: /* mrs cpsr. */
tmp = new_tmp();
if (IS_M(env)) {
--
1.6.6
