runqemu: Let qemuparams override default settings

Fixed:
In meta/conf/machine/include/qemuboot-x86.inc:
QB_CPU_x86-64 = "-cpu core2duo"

$ runqemu qemux86-64 qemuparams="-cpu coreduo"
Check /proc/cpuinfo, it should use coreduo rather than core2duo since user
specifies it, but it doesn't, append qemuparams to the last can fix the
problem.

[YOCTO #11773]

(From OE-Core rev: a847dd7202a2c493788c45d11eb86866264af7a4)

(From OE-Core rev: 81ab6332bee0426201626cc8a0339ce3e6b81d6f)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu

@@ -188,6 +188,7 @@ class BaseConfig(object):
 
         self.qemu_opt = ''
         self.qemu_opt_script = ''
+        self.qemuparams = ''
         self.clean_nfs_dir = False
         self.nfs_server = ''
         self.rootfs = ''
@@ -455,7 +456,7 @@ class BaseConfig(object):
             elif arg.startswith('biosfilename='):
                 self.qemu_opt_script += ' -bios %s' % arg[len('biosfilename='):]
             elif arg.startswith('qemuparams='):
-                self.qemu_opt_script += ' %s' % arg[len('qemuparams='):]
+                self.qemuparams = ' %s' % arg[len('qemuparams='):]
             elif arg.startswith('bootparams='):
                 self.bootparams = arg[len('bootparams='):]
             elif os.path.exists(arg) or (re.search(':', arg) and re.search('/', arg)):
@@ -662,7 +663,11 @@ class BaseConfig(object):
             raise RunQemuError("Invalid custombiosdir: %s" % self.custombiosdir)
 
     def check_mem(self):
-        s = re.search('-m +([0-9]+)', self.qemu_opt_script)
+        """
+        Both qemu and kernel needs memory settings, so check QB_MEM and set it
+        for both.
+        """
+        s = re.search('-m +([0-9]+)', self.qemuparams)
         if s:
             self.set('QB_MEM', '-m %s' % s.group(1))
         elif not self.get('QB_MEM'):
@@ -1164,6 +1169,10 @@ class BaseConfig(object):
 
         self.qemu_opt += ' ' + self.qemu_opt_script
 
+        # Append qemuparams to override previous settings
+        if self.qemuparams:
+            self.qemu_opt += ' ' + self.qemuparams
+
         if self.snapshot:
             self.qemu_opt += " -snapshot"