[PATCH 2/2] BaseTools/FMMT: Add Shrink Fv function

["Yuwei Chen" <yuwei.chen@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3938

This function is used to remove the useless FV free space.
Usage: FMMT -s Inputfile Outputfile

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Yuwei Chen <yuwei.chen@intel.com>
---
 BaseTools/Source/Python/FMMT/FMMT.py          |  7 +++++
 .../Source/Python/FMMT/core/FMMTOperation.py  | 26 +++++++++++++++++
 .../Source/Python/FMMT/core/FvHandler.py      | 28 ++++++++++++++++++-
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/BaseTools/Source/Python/FMMT/FMMT.py b/BaseTools/Source/Python/FMMT/FMMT.py
index 3590f3340ec3..bf580b3843a8 100644
--- a/BaseTools/Source/Python/FMMT/FMMT.py
+++ b/BaseTools/Source/Python/FMMT/FMMT.py
@@ -41,6 +41,8 @@ parser.add_argument("-c", "--ConfigFilePath", dest="ConfigFilePath", nargs='+',
                         FmmtConf file saves the target guidtool used in compress/uncompress process.\
                         If do not provide, FMMT tool will search the inputfile folder for FmmtConf.ini firstly, if not found,\
                         the FmmtConf.ini saved in FMMT tool's folder will be used as default.")
+parser.add_argument("-s", "--ShrinkFv", dest="ShrinkFv", nargs='+',
+                    help="Shrink the Fv file: '-s InputFvfile OutputFvfile")
 
 def print_banner():
     print("")
@@ -111,6 +113,9 @@ class FMMT():
         else:
             ReplaceFfs(inputfile, self.CheckFfsName(Ffs_name), newffsfile, outputfile)
 
+    def Shrink(self,inputfile: str, outputfile: str) -> None:
+        self.SetDestPath(inputfile)
+        ShrinkFv(inputfile, outputfile)
 
 def main():
     args=parser.parse_args()
@@ -142,6 +147,8 @@ def main():
                 fmmt.Replace(args.Replace[0],args.Replace[2],args.Replace[3],args.Replace[4],args.Replace[1])
             else:
                 fmmt.Replace(args.Replace[0],args.Replace[1],args.Replace[2],args.Replace[3])
+        elif args.ShrinkFv:
+            fmmt.Shrink(args.ShrinkFv[0], args.ShrinkFv[1])
         else:
             parser.print_help()
     except Exception as e:
diff --git a/BaseTools/Source/Python/FMMT/core/FMMTOperation.py b/BaseTools/Source/Python/FMMT/core/FMMTOperation.py
index 4e58c91b5c41..a86f8dda9a1a 100644
--- a/BaseTools/Source/Python/FMMT/core/FMMTOperation.py
+++ b/BaseTools/Source/Python/FMMT/core/FMMTOperation.py
@@ -204,3 +204,29 @@ def ExtractFfs(inputfile: str, Ffs_name: str, outputfile: str, Fv_name: str=None
             logger.debug('Extract ffs data is saved in {}.'.format(outputfile))
     else:
         logger.error('Target Ffs/Fv not found!!!')
+
+def ShrinkFv(inputfile: str, outputfile: str) -> None:
+    if not os.path.exists(inputfile):
+        logger.error("Invalid inputfile, can not open {}.".format(inputfile))
+        raise Exception("Process Failed: Invalid inputfile!")
+    # 1. Data Prepare
+    with open(inputfile, "rb") as f:
+        whole_data = f.read()
+    FmmtParser = FMMTParser(inputfile, ROOT_TREE)
+    # 2. DataTree Create
+    logger.debug('Parsing inputfile data......')
+    FmmtParser.ParserFromRoot(FmmtParser.WholeFvTree, whole_data)
+    logger.debug('Done!')
+    TargetFv = FmmtParser.WholeFvTree.Child[0]
+    if TargetFv:
+        FvMod = FvHandler(TargetFv)
+        Status = FvMod.ShrinkFv()
+    else:
+        logger.error('Target Fv not found!!!')
+    # 4. Data Encapsulation
+    if Status:
+        logger.debug('Start encapsulating data......')
+        FmmtParser.Encapsulation(FmmtParser.WholeFvTree, False)
+        with open(outputfile, "wb") as f:
+            f.write(FmmtParser.FinalData)
+        logger.debug('Encapsulated data is saved in {}.'.format(outputfile))
diff --git a/BaseTools/Source/Python/FMMT/core/FvHandler.py b/BaseTools/Source/Python/FMMT/core/FvHandler.py
index e8b848009878..ff3d637623f8 100644
--- a/BaseTools/Source/Python/FMMT/core/FvHandler.py
+++ b/BaseTools/Source/Python/FMMT/core/FvHandler.py
@@ -145,7 +145,7 @@ def ModifyFvSystemGuid(TargetFv) -> None:
             TargetFv.Data.Data += struct2stream(item.Data.Header)+ item.Data.Data + item.Data.PadData
 
 class FvHandler:
-    def __init__(self, NewFfs, TargetFfs) -> None:
+    def __init__(self, NewFfs, TargetFfs=None) -> None:
         self.NewFfs = NewFfs
         self.TargetFfs = TargetFfs
         self.Status = False
@@ -638,3 +638,29 @@ class FvHandler:
         self.Status = True
         logger.debug('Done!')
         return self.Status
+
+    def ShrinkFv(self) -> bool:
+        TargetFv = self.NewFfs
+        TargetFv.Data.Data = b''
+        if not TargetFv.Data.Free_Space:
+            self.Status = True
+        else:
+            BlockSize = TargetFv.Data.Header.BlockMap[0].Length
+            New_Free_Space = TargetFv.Data.Free_Space%BlockSize
+            Removed_Space = TargetFv.Data.Free_Space - New_Free_Space
+            TargetFv.Child[-1].Data.Data = b'\xff' * New_Free_Space
+            TargetFv.Data.Size -= Removed_Space
+            TargetFv.Data.Header.Fvlength = TargetFv.Data.Size
+            ModifyFvSystemGuid(TargetFv)
+            for item in TargetFv.Child:
+                if item.type == FFS_FREE_SPACE:
+                    TargetFv.Data.Data += item.Data.Data + item.Data.PadData
+                else:
+                    TargetFv.Data.Data += struct2stream(item.Data.Header)+ item.Data.Data + item.Data.PadData
+            TargetFv.Data.ModFvExt()
+            TargetFv.Data.ModFvSize()
+            TargetFv.Data.ModExtHeaderData()
+            ModifyFvExtData(TargetFv)
+            TargetFv.Data.ModCheckSum()
+            self.Status = True
+        return self.Status
-- 
2.27.0.windows.1