wic: 'wic cp' to copy from image

currently 'wic cp' only works for copy file from local storage to
wic image.

enhance 'wic cp' to copy file/directory from wic image to local storage.

include selftest and 'wic help' updates.

[YOCTO#12169]

(From OE-Core rev: bd669c1809a378f93580eb9e0679a26ec6746cb8)

Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/wic/engine.py

@@ -323,16 +323,31 @@ class Disk:
                                                    self._get_part_image(pnum),
                                                    path))
 
-    def copy(self, src, pnum, path):
+    def copy(self, src, dest):
         """Copy partition image into wic image."""
+        pnum =  dest.part if isinstance(src, str) else src.part
+
         if self.partitions[pnum].fstype.startswith('ext'):
-            cmd = "printf 'cd {}\nwrite {} {}\n' | {} -w {}".\
-                      format(path, src, os.path.basename(src),
+            if isinstance(src, str):
+                cmd = "printf 'cd {}\nwrite {} {}\n' | {} -w {}".\
+                      format(os.path.dirname(dest.path), src, os.path.basename(src),
                              self.debugfs, self._get_part_image(pnum))
+            else: # copy from wic
+                # run both dump and rdump to support both files and directory
+                cmd = "printf 'cd {}\ndump /{} {}\nrdump /{} {}\n' | {} {}".\
+                      format(os.path.dirname(src.path), src.path,
+                             dest, src.path, dest, self.debugfs,
+                             self._get_part_image(pnum))
         else: # fat
-            cmd = "{} -i {} -snop {} ::{}".format(self.mcopy,
+            if isinstance(src, str):
+                cmd = "{} -i {} -snop {} ::{}".format(self.mcopy,
                                                   self._get_part_image(pnum),
-                                                  src, path)
+                                                  src, dest.path)
+            else:
+                cmd = "{} -i {} -snop ::{} {}".format(self.mcopy,
+                                                  self._get_part_image(pnum),
+                                                  src.path, dest)
+
         exec_cmd(cmd, as_shell=True)
         self._put_part_image(pnum)
 
@@ -551,11 +566,15 @@ def wic_ls(args, native_sysroot):
 
 def wic_cp(args, native_sysroot):
     """
-    Copy local file or directory to the vfat partition of
+    Copy file or directory to/from the vfat/ext partition of
     partitioned image.
     """
-    disk = Disk(args.dest.image, native_sysroot)
-    disk.copy(args.src, args.dest.part, args.dest.path)
+    if isinstance(args.dest, str):
+        disk = Disk(args.src.image, native_sysroot)
+    else:
+        disk = Disk(args.dest.image, native_sysroot)
+    disk.copy(args.src, args.dest)
+
 
 def wic_rm(args, native_sysroot):
     """

scripts/lib/wic/help.py

@@ -341,12 +341,15 @@ DESCRIPTION
 
 wic_cp_usage = """
 
- Copy files and directories to the vfat or ext* partition
+ Copy files and directories to/from the vfat or ext* partition
 
- usage: wic cp <src> <image>:<partition>[<path>] [--native-sysroot <path>]
+ usage: wic cp <src> <dest> [--native-sysroot <path>]
 
- This command  copies local files or directories to the vfat or ext* partitions
-of partitioned  image.
+ source/destination image in format <image>:<partition>[<path>]
+
+ This command copies files or directories either
+  - from local to vfat or ext* partitions of partitioned image
+  - from vfat or ext* partitions of partitioned image to local
 
  See 'wic help cp' for more detailed instructions.
 
@@ -355,16 +358,18 @@ of partitioned  image.
 wic_cp_help = """
 
 NAME
-    wic cp - copy files and directories to the vfat or ext* partitions
+    wic cp - copy files and directories to/from the vfat or ext* partitions
 
 SYNOPSIS
-    wic cp <src> <image>:<partition>
-    wic cp <src> <image>:<partition><path>
-    wic cp <src> <image>:<partition><path> --native-sysroot <path>
+    wic cp <src> <dest>:<partition>
+    wic cp <src>:<partition> <dest>
+    wic cp <src> <dest-image>:<partition><path>
+    wic cp <src> <dest-image>:<partition><path> --native-sysroot <path>
 
 DESCRIPTION
-    This command copies files and directories to the vfat or ext* partition of
-    the partitioned image.
+    This command copies files or directories either
+      - from local to vfat or ext* partitions of partitioned image
+      - from vfat or ext* partitions of partitioned image to local
 
     The first form of it copies file or directory to the root directory of
     the partition:
@@ -397,6 +402,10 @@ DESCRIPTION
                4 files                   0 bytes
                                 15 675 392 bytes free
 
+    The third form of the command copies file or directory from the specified directory
+    on the partition to local:
+       $ wic cp tmp/deploy/images/qemux86-64/core-image-minimal-qemux86-64.wic:1/vmlinuz test
+
     The -n option is used to specify the path to the native sysroot
     containing the tools(parted and mtools) to use.
 """