Index: test/tools/llvm-objcopy/basic-only-keep.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/basic-only-keep.test
@@ -0,0 +1,21 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -j=.test %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .test
+    Type:            SHT_PROGBITS
+    Flags:           [ ]
+
+# CHECK: SectionHeaderCount: 5
+
+# CHECK:     Name: .test
+# CHECK:     Name: .symtab
+# CHECK:     Name: .strtab
+# CHECK:     Name: .shstrtab
Index: test/tools/llvm-objcopy/binary-only-keep-error.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/binary-only-keep-error.test
@@ -0,0 +1,11 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-objcopy -O binary -j .foo -j .bar %t %t2 2>&1 >/dev/null | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+
+# CHECK: -O binary and -j can only be used together with a single -j
Index: test/tools/llvm-objcopy/dump-section.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/dump-section.test
@@ -0,0 +1,26 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -O binary -j .text %t %t2
+# RUN: od -t x1 %t2 | FileCheck %s
+# RUN: wc -c %t2 | FileCheck %s --check-prefix=SIZE
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000001000
+    Content:         "DEADBEEF"
+ProgramHeaders:
+- Type: PT_LOAD
+  Flags: [ PF_X, PF_R ]
+  Sections:
+    - Section: .text
+
+#CHECK: 0000000 de ad be ef
+
+#SIZE: 4
Index: test/tools/llvm-objcopy/only-keep-many.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/only-keep-many.test
@@ -0,0 +1,28 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -j .test1 -j .test2 %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .test1
+    Type:            SHT_PROGBITS
+    Flags:           [ ]
+  - Name:            .test2
+    Type:            SHT_PROGBITS
+    Flags:           [ ]
+  - Name:            .test3
+    Type:            SHT_PROGBITS
+    Flags:           [ ]
+
+# CHECK: SectionHeaderCount: 6
+
+# CHECK:     Name: .test1
+# CHECK:     Name: .test2
+# CHECK:     Name: .symtab
+# CHECK:     Name: .strtab
+# CHECK:     Name: .shstrtab
Index: tools/llvm-objcopy/Object.h
===================================================================
--- tools/llvm-objcopy/Object.h
+++ tools/llvm-objcopy/Object.h
@@ -179,6 +179,7 @@
 
 public:
   void setStrTab(StringTableSection *StrTab) { SymbolNames = StrTab; }
+  const StringTableSection *getStrTab() const { return SymbolNames; }
   void addSymbol(llvm::StringRef Name, uint8_t Bind, uint8_t Type,
                  SectionBase *DefinedIn, uint64_t Value, uint16_t Shndx,
                  uint64_t Sz);
@@ -349,6 +350,10 @@
   bool WriteSectionHeaders = true;
 
   Object(const llvm::object::ELFObjectFile<ELFT> &Obj);
+  const StringTableSection *getSectionHeaderStrTab() const {
+    return SectionNames;
+  }
+  const SymbolTableSection *getSymTab() const { return SymbolTable; }
   void removeSections(std::function<bool(const SectionBase &)> ToRemove);
   virtual size_t totalSize() const = 0;
   virtual void finalize() = 0;
@@ -389,4 +394,24 @@
   size_t totalSize() const override;
   void write(llvm::FileOutputBuffer &Out) const override;
 };
+
+template <class ELFT> class SectionDump : public Object<ELFT> {
+private:
+  SectionBase *SectionToOutput = nullptr;
+
+public:
+  SectionDump(const llvm::object::ELFObjectFile<ELFT> &Obj,
+              llvm::StringRef SecName)
+      : Object<ELFT>(Obj) {
+    for (auto &Sec : this->Sections) {
+      if (Sec->Name == SecName) {
+        SectionToOutput = Sec.get();
+        return;
+      }
+    }
+  }
+  void finalize() override;
+  size_t totalSize() const override;
+  void write(llvm::FileOutputBuffer &Out) const override;
+};
 #endif
Index: tools/llvm-objcopy/Object.cpp
===================================================================
--- tools/llvm-objcopy/Object.cpp
+++ tools/llvm-objcopy/Object.cpp
@@ -825,11 +825,31 @@
   TotalSize = Offset;
 }
 
+template <class ELFT> size_t SectionDump<ELFT>::totalSize() const {
+  if (SectionToOutput == nullptr)
+    return 0;
+  return SectionToOutput->Size;
+}
+
+template <class ELFT>
+void SectionDump<ELFT>::write(FileOutputBuffer &Out) const {
+  SectionToOutput->writeSection(Out);
+}
+
+template <class ELFT> void SectionDump<ELFT>::finalize() {
+  SectionToOutput->Offset = 0;
+}
+
 template class Object<ELF64LE>;
 template class Object<ELF64BE>;
 template class Object<ELF32LE>;
 template class Object<ELF32BE>;
 
+template class SectionDump<ELF64LE>;
+template class SectionDump<ELF64BE>;
+template class SectionDump<ELF32LE>;
+template class SectionDump<ELF32BE>;
+
 template class ELFObject<ELF64LE>;
 template class ELFObject<ELF64BE>;
 template class ELFObject<ELF32LE>;
Index: tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- tools/llvm-objcopy/llvm-objcopy.cpp
+++ tools/llvm-objcopy/llvm-objcopy.cpp
@@ -58,6 +58,10 @@
                                "\n\tbinary"));
 cl::list<std::string> ToRemove("remove-section",
                                cl::desc("Remove a specific section"));
+cl::list<std::string>
+    OnlySection("only-section", cl::desc("Remove all but a specific section"));
+cl::alias OnlySectionA("j", cl::desc("Alias for only-section"),
+                       cl::aliasopt(OnlySection));
 cl::alias ToRemoveA("R", cl::desc("Alias for remove-section"),
                     cl::aliasopt(ToRemove));
 cl::opt<bool> StripSections("strip-sections",
@@ -70,10 +74,20 @@
   std::unique_ptr<Object<ELF64LE>> Obj;
   if (!OutputFormat.empty() && OutputFormat != "binary")
     error("invalid output format '" + OutputFormat + "'");
-  if (!OutputFormat.empty() && OutputFormat == "binary")
-    Obj = llvm::make_unique<BinaryObject<ELF64LE>>(ObjFile);
-  else
+  if (!OutputFormat.empty() && OutputFormat == "binary") {
+    // When the user uses -O binary and -j together they're likely meaning to
+    // dump the section contents of that section. This is a fairly common
+    // pattern in GNU objcopy so we should support it.
+    if (!OnlySection.empty()) {
+      if (OnlySection.size() != 1)
+        error("-O binary and -j can only be used together with a single -j");
+      Obj = llvm::make_unique<SectionDump<ELF64LE>>(ObjFile, OnlySection[0]);
+    } else {
+      Obj = llvm::make_unique<BinaryObject<ELF64LE>>(ObjFile);
+    }
+  } else {
     Obj = llvm::make_unique<ELFObject<ELF64LE>>(ObjFile);
+  }
 
   SectionPred RemovePred = [](const SectionBase &) { return false; };
 
@@ -84,6 +98,21 @@
     };
   }
 
+  if (!OnlySection.empty()) {
+    RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
+      if (RemovePred(Sec))
+        return true;
+      if (&Sec == Obj->getSectionHeaderStrTab())
+        return false;
+      if (&Sec == Obj->getSymTab() || &Sec == Obj->getSymTab()->getStrTab())
+        return false;
+      if (Sec.Type == SHT_SYMTAB)
+        return false;
+      return std::find(std::begin(OnlySection), std::end(OnlySection),
+                       Sec.Name) == std::end(OnlySection);
+    };
+  }
+
   if (StripSections) {
     RemovePred = [RemovePred](const SectionBase &Sec) {
       return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;