tools: bt: add syscall interface

The bt data handler needs a handle to a syscall interface to do things
like opening files and reading their contents.

Change-Id: Iacf26665eea2b0ed77b7ac2fd8d272d7518664d8
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/tools/bt.hpp b/tools/bt.hpp
index d4710ce..f407afa 100644
--- a/tools/bt.hpp
+++ b/tools/bt.hpp
@@ -2,6 +2,7 @@
 
 #include "blob_interface.hpp"
 #include "interface.hpp"
+#include "internal/sys.hpp"
 
 namespace host_tool
 {
@@ -9,7 +10,10 @@
 class BtDataHandler : public DataInterface
 {
   public:
-    explicit BtDataHandler(BlobInterface* blob) : blob(blob){};
+    BtDataHandler(BlobInterface* blob,
+                  const internal::Sys* sys = &internal::sys_impl) :
+        blob(blob),
+        sys(sys){};
 
     bool sendContents(const std::string& input, std::uint16_t session) override;
     blobs::FirmwareBlobHandler::UpdateFlags supportedType() const override
@@ -19,6 +23,7 @@
 
   private:
     BlobInterface* blob;
+    const internal::Sys* sys;
     blobs::FirmwareBlobHandler::UpdateFlags flags =
         blobs::FirmwareBlobHandler::UpdateFlags::ipmi;
 };