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-rw-r--r--target-arm/translate-a64.c43
1 files changed, 41 insertions, 2 deletions
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index bab890d932..ce2f841e36 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -384,10 +384,49 @@ static void disas_exc(DisasContext *s, uint32_t insn)
unsupported_encoding(s, insn);
}
-/* Unconditional branch (register) */
+/* C3.2.7 Unconditional branch (register)
+ * 31 25 24 21 20 16 15 10 9 5 4 0
+ * +---------------+-------+-------+-------+------+-------+
+ * | 1 1 0 1 0 1 1 | opc | op2 | op3 | Rn | op4 |
+ * +---------------+-------+-------+-------+------+-------+
+ */
static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
{
- unsupported_encoding(s, insn);
+ unsigned int opc, op2, op3, rn, op4;
+
+ opc = extract32(insn, 21, 4);
+ op2 = extract32(insn, 16, 5);
+ op3 = extract32(insn, 10, 6);
+ rn = extract32(insn, 5, 5);
+ op4 = extract32(insn, 0, 5);
+
+ if (op4 != 0x0 || op3 != 0x0 || op2 != 0x1f) {
+ unallocated_encoding(s);
+ return;
+ }
+
+ switch (opc) {
+ case 0: /* BR */
+ case 2: /* RET */
+ break;
+ case 1: /* BLR */
+ tcg_gen_movi_i64(cpu_reg(s, 30), s->pc);
+ break;
+ case 4: /* ERET */
+ case 5: /* DRPS */
+ if (rn != 0x1f) {
+ unallocated_encoding(s);
+ } else {
+ unsupported_encoding(s, insn);
+ }
+ return;
+ default:
+ unallocated_encoding(s);
+ return;
+ }
+
+ tcg_gen_mov_i64(cpu_pc, cpu_reg(s, rn));
+ s->is_jmp = DISAS_JUMP;
}
/* C3.2 Branches, exception generating and system instructions */