[OE-core] [PATCH 8/9] runqemu: support UEFI with OVMF firmware

[Patrick Ohly]

In the simplest case, "runqemu qemux86 <some-image> qcow2 ovmf" for an
EFI-enabled image in the qcow2 format will locate the OVMF firmware file,
override the graphics hardware with "-vga std" because that is all
that OVMF supports, and boot with UEFI enabled. This depends on
"bitbake ovmf" deploying a "ovmf.qcow2" firmware file in the image deploy
directory.

The firmware file is activated as a flash drive instead of using the
qemu BIOS parameters, because that is the recommended method
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=764918#47) as it
allows storing UEFI variables in the file.

Instead of just "ovmf", a full path to an existing file can also be
used, just as with the rootfs. That may be useful when making a
permanent copy of the virtual machine data files.

Signed-off-by: Patrick Ohly <patrick.ohly at intel.com>
---
 scripts/runqemu | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/scripts/runqemu b/scripts/runqemu
index 203992a..257dcec 100755
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -74,6 +74,7 @@ of the following environment variables (in any order):
     kvm-vhost - enable KVM with vhost when running x86/x86_64 (VT-capable CPU required)
     publicvnc - enable a VNC server open to all hosts
     audio - enable audio
+    [*/]ovmf* - OVMF BIOS file or base name for booting with UEFI
   tcpserial=<port> - specify tcp serial port number
   biosdir=<dir> - specify custom bios dir
   biosfilename=<filename> - specify bios filename
@@ -162,6 +163,12 @@ class BaseConfig(object):
         self.clean_nfs_dir = False
         self.nfs_server = ''
         self.rootfs = ''
+        # File name of a OVMF BIOS file, to be added with -drive if=pflash.
+        # Found in the same places as the rootfs, with or without one of
+        # these suffices: qcow2, bin.
+        # Setting one also adds "-vga std" because that is all that
+        # OVMF supports.
+        self.ovmf_bios = ''
         self.qemuboot = ''
         self.qbconfload = False
         self.kernel = ''
@@ -369,6 +376,8 @@ class BaseConfig(object):
                 self.qemu_opt_script += ' %s' % arg[len('qemuparams='):]
             elif arg.startswith('bootparams='):
                 self.kernel_cmdline_script += ' %s' % arg[len('bootparams='):]
+            elif os.path.basename(arg).startswith('ovmf'):
+                self.ovmf_bios = arg
             elif os.path.exists(arg) or (re.search(':', arg) and re.search('/', arg)):
                 self.check_arg_path(os.path.abspath(arg))
             elif re.search('-image-', arg):
@@ -472,6 +481,20 @@ class BaseConfig(object):
         if not os.path.exists(self.rootfs):
             raise Exception("Can't find rootfs: %s" % self.rootfs)
 
+    def check_ovmf(self):
+        """Check and set full path for OVMF BIOS file."""
+
+        if self.ovmf_bios is None or os.path.exists(self.ovmf_bios):
+            return
+
+        for suffix in ('qcow2', 'bin'):
+            ovmf_bios = '%s/%s.%s' % (self.get('DEPLOY_DIR_IMAGE'), self.ovmf_bios, suffix)
+            if os.path.exists(ovmf_bios):
+                self.ovmf_bios = ovmf_bios
+                return
+
+        raise Exception("Can't find OVMF BIOS: %s" % self.ovmf_bios)
+
     def check_kernel(self):
         """Check and set kernel, dtb"""
         # The vm image doesn't need a kernel
@@ -562,6 +585,7 @@ class BaseConfig(object):
         self.check_kvm()
         self.check_fstype()
         self.check_rootfs()
+        self.check_ovmf()
         self.check_kernel()
         self.check_biosdir()
         self.check_mem()
@@ -670,6 +694,8 @@ class BaseConfig(object):
             print('NFS_DIR: [%s]' % self.nfs_dir)
         else:
             print('ROOTFS: [%s]' % self.rootfs)
+        if self.ovmf_bios:
+            print('OVMF: [%s]' % self.ovmf_bios)
         print('CONFFILE: [%s]' % self.qemuboot)
         print('')
 
@@ -926,7 +952,16 @@ class BaseConfig(object):
 
         check_libgl(qemu_bin)
 
-        self.qemu_opt = "%s %s %s %s %s" % (qemu_bin, self.get('NETWORK_CMD'), self.get('ROOTFS_OPTIONS'), self.get('QB_OPT_APPEND'), self.qemu_opt_script)
+        self.qemu_opt = "%s %s %s %s" % (qemu_bin, self.get('NETWORK_CMD'), self.get('ROOTFS_OPTIONS'), self.get('QB_OPT_APPEND'))
+
+        if self.ovmf_bios:
+            format = self.ovmf_bios.rsplit('.', 1)[-1]
+            self.qemu_opt += ' -drive if=pflash,format=%s,file=%s' % (format, self.ovmf_bios)
+            # OVMF only supports normal VGA, i.e. we need to override a -vga vmware
+            # that gets added for example for normal qemux86.
+            self.qemu_opt += ' -vga std'
+
+        self.qemu_opt += ' ' + self.qemu_opt_script
 
         if self.snapshot:
             self.qemu_opt += " -snapshot"
-- 
2.1.4