lpmake: Allow writing split super images.

To use this mode, the build must be a retrofit build and --output should
be a folder rather than a file.

This also fixes a bug in lpdump where it refuses to dump full super.img
images on the host.

Bug: 118887112
Test: manual test
Change-Id: I3318684fbea6fe67bfa171001beea3a5c560fbab

2 files changed, 10 insertions, 6 deletions

diff --git a/partition_tools/lpdump.cc b/partition_tools/lpdump.cc
index 689ffb13..e3689d23 100644
--- a/partition_tools/lpdump.cc
+++ b/partition_tools/lpdump.cc
@@ -84,10 +84,8 @@ int main(int argc, char* argv[]) {
     }
     const char* file = argv[optind++];
 
-    std::unique_ptr<LpMetadata> pt;
-    if (IsBlockDevice(file)) {
-        pt = ReadMetadata(file, slot);
-    } else {
+    auto pt = ReadMetadata(file, slot);
+    if (!pt && !IsBlockDevice(file)) {
         pt = ReadFromImageFile(file);
     }
     if (!pt) {
diff --git a/partition_tools/lpmake.cc b/partition_tools/lpmake.cc
index 7a2ba518..1c11c4d2 100644
--- a/partition_tools/lpmake.cc
+++ b/partition_tools/lpmake.cc
@@ -352,8 +352,14 @@ int main(int argc, char* argv[]) {
 
     std::unique_ptr<LpMetadata> metadata = builder->Export();
     if (output_sparse) {
-        if (!WriteToSparseFile(output_path.c_str(), *metadata.get(), block_size, images)) {
-            return EX_CANTCREAT;
+        if (block_devices.size() == 1) {
+            if (!WriteToSparseFile(output_path.c_str(), *metadata.get(), block_size, images)) {
+                return EX_CANTCREAT;
+            }
+        } else {
+            if (!WriteSplitSparseFiles(output_path, *metadata.get(), block_size, images)) {
+                return EX_CANTCREAT;
+            }
         }
     } else if (!WriteToImageFile(output_path.c_str(), *metadata.get())) {
         return EX_CANTCREAT;