[Qemu-devel] [PATCH v1 2/4] target/arm: handle A-profile T32 semihosting at translate time

["Alex Bennée" <alex.bennee@linaro.org>]

As for the other semihosting calls we can resolve this at translate
time.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 target/arm/translate.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index aaab043636..8e2e955cbe 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -10995,6 +10995,24 @@ static inline void gen_thumb_bkpt(DisasContext *s, int imm8)
     gen_exception_bkpt_insn(s, 2, syn_aa32_bkpt(imm8, true));
 }
 
+/*
+ * Thumb SWI. On A-profile CPUs this may be a semihosting call.
+ */
+static inline void gen_thumb_swi(DisasContext *s, int imm8)
+{
+    if (semihosting_enabled() &&
+#ifndef CONFIG_USER_ONLY
+        s->current_el != 0 &&
+#endif
+        (imm8 == 0xab)) {
+        gen_exception_internal_insn(s, 0, EXCP_SEMIHOST);
+        return;
+    }
+    gen_set_pc_im(s, s->pc);
+    s->svc_imm = imm8;
+    s->base.is_jmp = DISAS_SWI;
+}
+
 static void disas_thumb_insn(DisasContext *s, uint32_t insn)
 {
     uint32_t val, op, rm, rn, rd, shift, cond;
@@ -11752,10 +11770,8 @@ static void disas_thumb_insn(DisasContext *s, uint32_t insn)
             goto undef;
 
         if (cond == 0xf) {
-            /* swi */
-            gen_set_pc_im(s, s->pc);
-            s->svc_imm = extract32(insn, 0, 8);
-            s->base.is_jmp = DISAS_SWI;
+            /* swi/svc  */
+            gen_thumb_swi(s, extract32(insn, 0, 8));
             break;
         }
         /* generate a conditional jump to next instruction */
-- 
2.20.1