Fix build tool with ARMC6/ARMv8M

1. Add linking time preprocessor macro __DOMAIN_NS for non-secure build
2. For output .hex format, combine multiple .hex files (for multiple load regions) into one
   This can help for Greentea test.
3. Fix 'None' build_dir with cmse_lib.o on Greentea test

Author: ccli8

tools/toolchains/arm.py

@@ -233,6 +233,11 @@ def link(self, output, objects, libraries, lib_dirs, scatter_file):
         cmd_pre = self.ld + args
         cmd = self.hook.get_cmdline_linker(cmd_pre)
 
+        # Create Secure library
+        if self.target.core == "Cortex-M23" or self.target.core == "Cortex-M33":
+            secure_file = join(dirname(output), "cmse_lib.o")
+            cmd.extend(["--import_cmse_lib_out=%s" % secure_file])
+
         if self.RESPONSE_FILES:
             cmd_linker = cmd[0]
             link_files = self.get_link_file(cmd[1:])
@@ -252,7 +257,8 @@ def archive(self, objects, lib_path):
     @hook_tool
     def binary(self, resources, elf, bin):
         _, fmt = splitext(bin)
-        bin_arg = {".bin": "--bin", ".hex": "--i32"}[fmt]
+        # On .hex format, combine multiple .hex files (for multiple load regions) into one 
+        bin_arg = {".bin": "--bin", ".hex": "--i32combined"}[fmt]
         cmd = [self.elf2bin, bin_arg, '-o', bin, elf]
         cmd = self.hook.get_cmdline_binary(cmd)
 
@@ -357,13 +363,12 @@ def __init__(self, target, *args, **kwargs):
 
         if target.core == "Cortex-M23" or target.core == "Cortex-M33":
             self.flags['common'].append("-mcmse")
-
-        # Create Secure library
-        if target.core == "Cortex-M23" or self.target.core == "Cortex-M33":
-            build_dir = kwargs['build_dir']
-            secure_file = join(build_dir, "cmse_lib.o")
-            self.flags["ld"] += ["--import_cmse_lib_out=%s" % secure_file]
-
+        
+        # Add linking time preprocessor macro __DOMAIN_NS
+        if target.core == "Cortex-M23-NS" or self.target.core == "Cortex-M33-NS":
+            define_string = self.make_ld_define("__DOMAIN_NS", 1)
+            self.flags["ld"].append(define_string)
+            
         asm_cpu = {
             "Cortex-M0+": "Cortex-M0",
             "Cortex-M4F": "Cortex-M4.fp",