From b8b45b68f8836c1db8422badf3c0c573a88f8b43 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Mon, 15 Feb 2010 00:02:35 +0530 Subject: [PATCH] target-arm: implement Thumb-2 exception return Support the "subs pc, lr" Thumb-2 exception return instruction. Signed-off-by: Rabin Vincent Signed-off-by: Paul Brook --- target-arm/translate.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/target-arm/translate.c b/target-arm/translate.c index 10a516b909..8b3b12d67e 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -8001,8 +8001,16 @@ 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; + } + if (rn != 14 || rd != 15) { + goto illegal_op; + } + tmp = load_reg(s, rn); + tcg_gen_subi_i32(tmp, tmp, insn & 0xff); + gen_exception_return(s, tmp); + break; case 6: /* mrs cpsr. */ tmp = new_tmp(); if (IS_M(env)) {