This adds handling for the b and bl instructions.
Signed-off-by: Alexander Graf <[email protected]>
---
target-arm/translate-a64.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 73ccade..267fd4d 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -133,6 +133,58 @@ static void real_unallocated_encoding(DisasContext *s)
real_unallocated_encoding(s); \
} while (0)
+static int get_bits(uint32_t inst, int start, int len)
+{
+ return (inst >> start) & ((1 << len) - 1);
+}
+
+static int get_sbits(uint32_t inst, int start, int len)
+{
+ int r = get_bits(inst, start, len);
+ if (r & (1 << (len - 1))) {
+ /* Extend the MSB 1 to the higher bits */
+ r |= -1 & ~((1ULL << len) - 1);
+ }
+ return r;
+}
+
+static TCGv_i64 cpu_reg(int reg)
+{
+ if (reg == 31) {
+ /* XXX leaks temps */
+ return tcg_const_i64(0);
+ } else {
+ return cpu_X[reg];
+ }
+}
+
+static inline void gen_goto_tb(DisasContext *s, int n, uint64_t dest)
+{
+ TranslationBlock *tb;
+
+ tb = s->tb;
+ if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {
+ tcg_gen_goto_tb(n);
+ gen_a64_set_pc_im(dest);
+ tcg_gen_exit_tb((tcg_target_long)tb + n);
+ } else {
+ gen_a64_set_pc_im(dest);
+ tcg_gen_exit_tb(0);
+ }
+}
+
+static void handle_b(DisasContext *s, uint32_t insn)
+{
+ uint64_t addr = s->pc - 4 + (get_sbits(insn, 0, 26) << 2);
+
+ if (get_bits(insn, 31, 1)) {
+ /* BL */
+ tcg_gen_movi_i64(cpu_reg(30), s->pc);
+ }
+ gen_goto_tb(s, 0, addr);
+ s->is_jmp = DISAS_TB_JUMP;
+}
+
void disas_a64_insn(CPUARMState *env, DisasContext *s)
{
uint32_t insn;
@@ -141,12 +193,21 @@ void disas_a64_insn(CPUARMState *env, DisasContext *s)
s->insn = insn;
s->pc += 4;
+ /* One-off branch instruction layout */
+ switch (insn >> 26) {
+ case 0x25:
+ case 0x5:
+ handle_b(s, insn);
+ goto insn_done;
+ }
+
switch ((insn >> 24) & 0x1f) {
default:
unallocated_encoding(s);
break;
}
+insn_done:
if (unlikely(s->singlestep_enabled) && (s->is_jmp == DISAS_TB_JUMP)) {
/* go through the main loop for single step */
s->is_jmp = DISAS_JUMP;
--
1.7.12.4
