M68k system mode semihosting.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@2861 c046a42c-6fe2-441c-8c8c-71466251a162

4 files changed, 28 insertions, 2 deletions

diff --git a/target-m68k/cpu.h b/target-m68k/cpu.h
index c916ad7cd..93080cfe1 100644
--- a/target-m68k/cpu.h
+++ b/target-m68k/cpu.h
@@ -51,6 +51,7 @@
 #define EXCP_ICE            13
 
 #define EXCP_RTE            0x100
+#define EXCP_HALT_INSN      0x101
 
 typedef struct CPUM68KState {
     uint32_t dregs[8];
@@ -148,6 +149,8 @@ void m68k_set_irq_level(CPUM68KState *env, int level, uint8_t vector);
 
 #define M68K_FPCR_PREC (1 << 6)
 
+void do_m68k_semihosting(CPUM68KState *env, int nr);
+
 #ifdef CONFIG_USER_ONLY
 /* Linux uses 8k pages.  */
 #define TARGET_PAGE_BITS 13
diff --git a/target-m68k/op.c b/target-m68k/op.c
index 6134bb018..69d1fde9a 100644
--- a/target-m68k/op.c
+++ b/target-m68k/op.c
@@ -383,8 +383,15 @@ OP(divs)
     FORCE_RET();
 }
 
+/* Halt is special because it may be a semihosting call.  */
 OP(halt)
 {
+    RAISE_EXCEPTION(EXCP_HALT_INSN);
+    FORCE_RET();
+}
+
+OP(stop)
+{
     env->halted = 1;
     RAISE_EXCEPTION(EXCP_HLT);
     FORCE_RET();
diff --git a/target-m68k/op_helper.c b/target-m68k/op_helper.c
index 7455e3165..f5593eca0 100644
--- a/target-m68k/op_helper.c
+++ b/target-m68k/op_helper.c
@@ -28,6 +28,8 @@ void do_interrupt(int is_hw)
 
 #else
 
+extern int semihosting_enabled;
+
 #define MMUSUFFIX _mmu
 #define GETPC() (__builtin_return_address(0))
 
@@ -104,6 +106,20 @@ void do_interrupt(int is_hw)
             /* Return from an exception.  */
             do_rte();
             return;
+        case EXCP_HALT_INSN:
+            if (semihosting_enabled
+                    && (env->sr & SR_S) != 0
+                    && (env->pc & 3) == 0
+                    && lduw_code(env->pc - 4) == 0x4e71
+                    && ldl_code(env->pc) == 0x4e7bf000) {
+                env->pc += 4;
+                do_m68k_semihosting(env, env->dregs[0]);
+                return;
+            }
+            env->halted = 1;
+            env->exception_index = EXCP_HLT;
+            cpu_loop_exit();
+            return;
         }
         if (env->exception_index >= EXCP_TRAP0
             && env->exception_index <= EXCP_TRAP15) {
diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index eff32867b..d7162fea6 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -1901,7 +1901,6 @@ DISAS_INSN(move_to_usp)
 
 DISAS_INSN(halt)
 {
-    gen_flush_cc_op(s);
     gen_jmp(s, gen_im32(s->pc));
     gen_op_halt();
 }
@@ -1919,7 +1918,8 @@ DISAS_INSN(stop)
     s->pc += 2;
 
     gen_set_sr_im(s, ext, 0);
-    disas_halt(s, insn);
+    gen_jmp(s, gen_im32(s->pc));
+    gen_op_stop();
 }
 
 DISAS_INSN(rte)