qemu.bbclass: add qemu_wrapper_cmdline()

The class had qemu_run_binary() which was not suitable for gobject-introspection,
as it required the name of the binary to run.

qemu_wrapper_cmdline() returns just the command line string needed to run
binaries, and does not require the binary name.

(From OE-Core rev: 0b68f0632312392cbd20bfcb9ed4895cfc9883ff)

Signed-off-by: Alexander Kanavin <alexander.kanavin@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/qemu.bbclass

@@ -13,7 +13,19 @@ def qemu_target_binary(data):
         target_arch = "ppc64"
 
     return "qemu-" + target_arch
-#
+
+def qemu_wrapper_cmdline(data, rootfs_path, library_paths):
+    import string
+
+    qemu_binary = qemu_target_binary(data)
+    if qemu_binary == "qemu-allarch":
+        qemu_binary = "qemuwrapper"
+
+    qemu_options = data.getVar("QEMU_OPTIONS", True)    
+
+    return "PSEUDO_UNLOAD=1 " + qemu_binary + " " + qemu_options + " -L " + rootfs_path\
+            + " -E LD_LIBRARY_PATH=" + ":".join(library_paths) + " "
+
 # Next function will return a string containing the command that is needed to
 # to run a certain binary through qemu. For example, in order to make a certain
 # postinstall scriptlet run at do_rootfs time and running the postinstall is
@@ -23,17 +35,10 @@ def qemu_target_binary(data):
 # ${@qemu_run_binary(d, '$D', '/usr/bin/test_app')} [test_app arguments]
 #
 def qemu_run_binary(data, rootfs_path, binary):
-    qemu_binary = qemu_target_binary(data)
-    if qemu_binary == "qemu-allarch":
-        qemu_binary = "qemuwrapper"
-
     libdir = rootfs_path + data.getVar("libdir", False)
     base_libdir = rootfs_path + data.getVar("base_libdir", False)
-    qemu_options = data.getVar("QEMU_OPTIONS", True)
 
-    return "PSEUDO_UNLOAD=1 " + qemu_binary + " " + qemu_options + " -L " + rootfs_path\
-            + " -E LD_LIBRARY_PATH=" + libdir + ":" + base_libdir + " "\
-            + rootfs_path + binary
+    return qemu_wrapper_cmdline(data, rootfs_path, [libdir, base_libdir]) + rootfs_path + binary
 
 # QEMU_EXTRAOPTIONS is not meant to be directly used, the extensions are
 # PACKAGE_ARCH, *NOT* overrides.