scripts: Move root-disk processing to helper

The build-efi and build-qemu scripts have common code to set up the root
disk. Move it to build_helper to avoid duplication.

Signed-off-by: Simon Glass <sjg@chromium.org>

scripts/build-efi

@@ -113,15 +113,6 @@ class BuildEfi:
         if self.args.kvm:
             extra.extend(['-enable-kvm', '-cpu', 'host'])
 
-        img_fname = Path(self.args.disk) if self.args.disk else None
-        if img_fname:
-            if img_fname.exists():
-                extra.extend([
-                    '-drive',
-                    f'if=virtio,file={img_fname},format=raw,id=hd1'])
-            else:
-                tout.warning(f"Disk image '{img_fname}' not found")
-
         print(f'Running {qemu}{serial_msg}')
 
         # Use 512MB since U-Boot EFI likes to have 256MB to play with

scripts/build-qemu

@@ -127,7 +127,6 @@ class BuildQemu:
                     f'{bios_override}')
 
         self.seq_fname = Path(args.sct_seq) if args.sct_seq else None
-        self.img_fname = Path(args.disk) if args.disk else None
 
         # arch-specific setup
         if args.arch == 'arm':
@@ -284,14 +283,6 @@ class BuildQemu:
         # Add other parameters gathered from options
         qemu_cmd.extend(self.qemu_extra)
 
-        if self.img_fname:
-            if self.img_fname.exists():
-                qemu_cmd.extend([
-                    '-drive',
-                    f'if=virtio,file={self.img_fname},format=raw,id=hd1'])
-            else:
-                tout.warning(f"Disk image '{self.img_fname}' not found")
-
         sock = Path('/tmp/virtiofs.sock')
         proc = None
         if self.args.share_dir:

scripts/build_helper.py

@@ -43,6 +43,7 @@ class Helper:
                 self.os_arch = 'amd64'
             else:
                 self.os_arch = 'i386'
+        self.img_fname = Path(args.disk) if args.disk else None
 
     def read_settings(self):
         """Get settings from the settings file"""
@@ -160,6 +161,14 @@ sct_mnt = /mnt/sct
                     '-drive',
                     f'if=virtio,file={os_path},format=raw,id=hd0,readonly=on'])
 
+        if self.img_fname:
+            if self.img_fname.exists():
+                cmd.extend([
+                    '-drive',
+                    f'if=virtio,file={self.img_fname},format=raw,id=hd1'])
+            else:
+                tout.warning(f"Disk image '{self.img_fname}' not found")
+
 
 def add_common_args(parser):
     """Add some arguments which are common to build-efi/qemu scripts