acpi: add aml_arg() term

Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/acpi/aml-build.c

@@ -397,6 +397,17 @@ Aml *aml_name_decl(const char *name, Aml *val)
     return var;
 }
 
+/* ACPI 1.0b: 16.2.6.1 Arg Objects Encoding */
+Aml *aml_arg(int pos)
+{
+    Aml *var;
+    uint8_t op = 0x68 /* ARG0 op */ + pos;
+
+    assert(pos <= 6);
+    var = aml_opcode(op);
+    return var;
+}
+
 /* ACPI 1.0b: 16.2.5.3 Type 1 Opcodes Encoding: DefIfElse */
 Aml *aml_if(Aml *predicate)
 {

include/hw/acpi/aml-build.h

@@ -64,6 +64,7 @@ Aml *aml_name(const char *name_format, ...) GCC_FMT_ATTR(1, 2);
 Aml *aml_name_decl(const char *name, Aml *val);
 Aml *aml_return(Aml *val);
 Aml *aml_int(const uint64_t val);
+Aml *aml_arg(int pos);
 
 /* Block AML object primitives */
 Aml *aml_scope(const char *name_format, ...) GCC_FMT_ATTR(1, 2);