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authorMichael Walle <michael@walle.cc>2013-09-23 20:47:33 +0200
committerMichael Walle <michael@walle.cc>2014-02-04 19:47:39 +0100
commit667ff9612b786f9bb5b70135811164b48b7d44eb (patch)
tree82e7dffb9c98421b72a4ae48772bc4b51eed307d /target-lm32/translate.c
parent8c5edce5b775f98cff2e340427740137bd6847be (diff)
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target-lm32: stop VM on illegal or unknown instruction
Instead of translating the instruction to a no-op, pause the VM and display a message to the user. As a side effect, this also works for instructions where the operands are only known at runtime. Signed-off-by: Michael Walle <michael@walle.cc>
Diffstat (limited to 'target-lm32/translate.c')
-rw-r--r--target-lm32/translate.c106
1 files changed, 68 insertions, 38 deletions
diff --git a/target-lm32/translate.c b/target-lm32/translate.c
index f20460a..80bffc7 100644
--- a/target-lm32/translate.c
+++ b/target-lm32/translate.c
@@ -122,6 +122,12 @@ static inline void t_gen_raise_exception(DisasContext *dc, uint32_t index)
tcg_temp_free_i32(tmp);
}
+static inline void t_gen_illegal_insn(DisasContext *dc)
+{
+ tcg_gen_movi_tl(cpu_pc, dc->pc);
+ gen_helper_ill(cpu_env);
+}
+
static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)
{
TranslationBlock *tb;
@@ -425,6 +431,7 @@ static void dec_divu(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_DIVIDE)) {
qemu_log_mask(LOG_GUEST_ERROR, "hardware divider is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -504,6 +511,7 @@ static void dec_modu(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_DIVIDE)) {
qemu_log_mask(LOG_GUEST_ERROR, "hardware divider is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -527,6 +535,7 @@ static void dec_mul(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_MULTIPLY)) {
qemu_log_mask(LOG_GUEST_ERROR,
"hardware multiplier is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -591,21 +600,21 @@ static void dec_orhi(DisasContext *dc)
static void dec_scall(DisasContext *dc)
{
- if (dc->imm5 == 7) {
- LOG_DIS("scall\n");
- } else if (dc->imm5 == 2) {
+ switch (dc->imm5) {
+ case 2:
LOG_DIS("break\n");
- } else {
- qemu_log_mask(LOG_GUEST_ERROR, "invalid opcode @0x%x", dc->pc);
- return;
- }
-
- if (dc->imm5 == 7) {
- tcg_gen_movi_tl(cpu_pc, dc->pc);
- t_gen_raise_exception(dc, EXCP_SYSTEMCALL);
- } else {
tcg_gen_movi_tl(cpu_pc, dc->pc);
t_gen_raise_exception(dc, EXCP_BREAKPOINT);
+ break;
+ case 7:
+ LOG_DIS("scall\n");
+ tcg_gen_movi_tl(cpu_pc, dc->pc);
+ t_gen_raise_exception(dc, EXCP_SYSTEMCALL);
+ break;
+ default:
+ qemu_log_mask(LOG_GUEST_ERROR, "invalid opcode @0x%x", dc->pc);
+ t_gen_illegal_insn(dc);
+ break;
}
}
@@ -681,6 +690,7 @@ static void dec_sextb(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_SIGN_EXTEND)) {
qemu_log_mask(LOG_GUEST_ERROR,
"hardware sign extender is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -694,6 +704,7 @@ static void dec_sexth(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_SIGN_EXTEND)) {
qemu_log_mask(LOG_GUEST_ERROR,
"hardware sign extender is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -722,6 +733,7 @@ static void dec_sl(DisasContext *dc)
if (!(dc->features & LM32_FEATURE_SHIFT)) {
qemu_log_mask(LOG_GUEST_ERROR, "hardware shifter is not available\n");
+ t_gen_illegal_insn(dc);
return;
}
@@ -743,24 +755,32 @@ static void dec_sr(DisasContext *dc)
LOG_DIS("sr r%d, r%d, r%d\n", dc->r2, dc->r0, dc->r1);
}
- if (!(dc->features & LM32_FEATURE_SHIFT)) {
- if (dc->format == OP_FMT_RI) {
- /* TODO: check r1 == 1 during runtime */
- } else {
- if (dc->imm5 != 1) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "hardware shifter is not available\n");
- return;
- }
- }
- }
-
+ /* The real CPU (w/o hardware shifter) only supports right shift by exactly
+ * one bit */
if (dc->format == OP_FMT_RI) {
+ if (!(dc->features & LM32_FEATURE_SHIFT) && (dc->imm5 != 1)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "hardware shifter is not available\n");
+ t_gen_illegal_insn(dc);
+ return;
+ }
tcg_gen_sari_tl(cpu_R[dc->r1], cpu_R[dc->r0], dc->imm5);
} else {
- TCGv t0 = tcg_temp_new();
+ int l1 = gen_new_label();
+ int l2 = gen_new_label();
+ TCGv t0 = tcg_temp_local_new();
tcg_gen_andi_tl(t0, cpu_R[dc->r1], 0x1f);
+
+ if (!(dc->features & LM32_FEATURE_SHIFT)) {
+ tcg_gen_brcondi_tl(TCG_COND_EQ, t0, 1, l1);
+ t_gen_illegal_insn(dc);
+ tcg_gen_br(l2);
+ }
+
+ gen_set_label(l1);
tcg_gen_sar_tl(cpu_R[dc->r2], cpu_R[dc->r0], t0);
+ gen_set_label(l2);
+
tcg_temp_free(t0);
}
}
@@ -773,24 +793,30 @@ static void dec_sru(DisasContext *dc)
LOG_DIS("sru r%d, r%d, r%d\n", dc->r2, dc->r0, dc->r1);
}
- if (!(dc->features & LM32_FEATURE_SHIFT)) {
- if (dc->format == OP_FMT_RI) {
- /* TODO: check r1 == 1 during runtime */
- } else {
- if (dc->imm5 != 1) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "hardware shifter is not available\n");
- return;
- }
- }
- }
-
if (dc->format == OP_FMT_RI) {
+ if (!(dc->features & LM32_FEATURE_SHIFT) && (dc->imm5 != 1)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "hardware shifter is not available\n");
+ t_gen_illegal_insn(dc);
+ return;
+ }
tcg_gen_shri_tl(cpu_R[dc->r1], cpu_R[dc->r0], dc->imm5);
} else {
- TCGv t0 = tcg_temp_new();
+ int l1 = gen_new_label();
+ int l2 = gen_new_label();
+ TCGv t0 = tcg_temp_local_new();
tcg_gen_andi_tl(t0, cpu_R[dc->r1], 0x1f);
+
+ if (!(dc->features & LM32_FEATURE_SHIFT)) {
+ tcg_gen_brcondi_tl(TCG_COND_EQ, t0, 1, l1);
+ t_gen_illegal_insn(dc);
+ tcg_gen_br(l2);
+ }
+
+ gen_set_label(l1);
tcg_gen_shr_tl(cpu_R[dc->r2], cpu_R[dc->r0], t0);
+ gen_set_label(l2);
+
tcg_temp_free(t0);
}
}
@@ -819,6 +845,7 @@ static void dec_user(DisasContext *dc)
LOG_DIS("user");
qemu_log_mask(LOG_GUEST_ERROR, "user instruction undefined\n");
+ t_gen_illegal_insn(dc);
}
static void dec_wcsr(DisasContext *dc)
@@ -886,6 +913,7 @@ static void dec_wcsr(DisasContext *dc)
if (dc->num_breakpoints <= no) {
qemu_log_mask(LOG_GUEST_ERROR,
"breakpoint #%i is not available\n", no);
+ t_gen_illegal_insn(dc);
break;
}
gen_helper_wcsr_bp(cpu_env, cpu_R[dc->r1], tcg_const_i32(no));
@@ -898,6 +926,7 @@ static void dec_wcsr(DisasContext *dc)
if (dc->num_watchpoints <= no) {
qemu_log_mask(LOG_GUEST_ERROR,
"watchpoint #%i is not available\n", no);
+ t_gen_illegal_insn(dc);
break;
}
gen_helper_wcsr_wp(cpu_env, cpu_R[dc->r1], tcg_const_i32(no));
@@ -956,6 +985,7 @@ static void dec_xor(DisasContext *dc)
static void dec_ill(DisasContext *dc)
{
qemu_log_mask(LOG_GUEST_ERROR, "invalid opcode 0x%02x\n", dc->opcode);
+ t_gen_illegal_insn(dc);
}
typedef void (*DecoderInfo)(DisasContext *dc);