diff --git a/Source/fileform.cpp b/Source/fileform.cpp
new file mode 100644
index 00000000..5abd08c8
--- /dev/null
+++ b/Source/fileform.cpp
@@ -0,0 +1,170 @@
+#include "fileform.h"
+#include "exehead/config.h"
+#include "Platform.h"
+
+#include <cassert>
+
+// these functions MUST be synchronized with the structures in Source/exehead/fileform.h !
+// data must be written in the same order it's defined in Source/exehead/fileform.h
+// in the future, i hope to get one of the two automtaically generated from the other
+
+void firstheader_writer::write(const firstheader *data)
+{
+  m_sink->write_int(data->flags);
+  m_sink->write_int(data->siginfo);
+  m_sink->write_int_array(data->nsinst, 3);
+  m_sink->write_int(data->length_of_header);
+  m_sink->write_int(data->length_of_all_following_data);
+}
+
+void block_header_writer::write(const block_header *data)
+{
+  m_sink->write_int(data->offset);
+  m_sink->write_int(data->num);
+}
+
+void header_writer::write(const header *data)
+{
+  m_sink->write_int(data->flags);
+
+  block_header_writer bw(writer::m_sink);
+  for (int i = 0; i < BLOCKS_NUM; i++)
+  {
+    bw.write(&data->blocks[i]);
+  }
+
+  m_sink->write_int(data->install_reg_rootkey);
+  m_sink->write_int(data->install_reg_key_ptr);
+  m_sink->write_int(data->install_reg_value_ptr);
+
+#ifdef NSIS_SUPPORT_BGBG
+  m_sink->write_int(data->bg_color1);
+  m_sink->write_int(data->bg_color2);
+  m_sink->write_int(data->bg_textcolor);
+#endif
+
+#ifdef NSIS_CONFIG_VISIBLE_SUPPORT
+  m_sink->write_int(data->lb_bg);
+  m_sink->write_int(data->lb_fg);
+#endif
+
+  m_sink->write_int(data->langtable_size);
+
+#ifdef NSIS_CONFIG_LICENSEPAGE
+  m_sink->write_int(data->license_bg);
+#endif//NSIS_CONFIG_LICENSEPAGE
+
+#ifdef NSIS_SUPPORT_CODECALLBACKS
+  m_sink->write_int(data->code_onInit);
+  m_sink->write_int(data->code_onInstSuccess);
+  m_sink->write_int(data->code_onInstFailed);
+  m_sink->write_int(data->code_onUserAbort);
+#ifdef NSIS_CONFIG_ENHANCEDUI_SUPPORT
+  m_sink->write_int(data->code_onGUIInit);
+  m_sink->write_int(data->code_onGUIEnd);
+  m_sink->write_int(data->code_onMouseOverSection);
+#endif//NSIS_CONFIG_ENHANCEDUI_SUPPORT
+  m_sink->write_int(data->code_onVerifyInstDir);
+#ifdef NSIS_CONFIG_COMPONENTPAGE
+  m_sink->write_int(data->code_onSelChange);
+#endif//NSIS_CONFIG_COMPONENTPAGE
+#ifdef NSIS_SUPPORT_REBOOT
+  m_sink->write_int(data->code_onRebootFailed);
+#endif//NSIS_SUPPORT_REBOOT
+#endif//NSIS_SUPPORT_CODECALLBACKS
+
+#ifdef NSIS_CONFIG_COMPONENTPAGE
+  m_sink->write_int_array(data->install_types, NSIS_MAX_INST_TYPES + 1);
+#endif
+
+  m_sink->write_int(data->install_directory_ptr);
+  m_sink->write_int(data->install_directory_auto_append);
+}
+
+void section_writer::write(const section *data)
+{
+  m_sink->write_int(data->name_ptr);
+  m_sink->write_int(data->install_types);
+  m_sink->write_int(data->flags);
+  m_sink->write_int(data->code);
+  m_sink->write_int(data->code_size);
+  m_sink->write_int(data->size_kb);
+  m_sink->write_string(data->name, NSIS_MAX_STRLEN);
+}
+
+void entry_writer::write(const entry *data)
+{
+  m_sink->write_int(data->which);
+  m_sink->write_int_array(data->offsets, MAX_ENTRY_OFFSETS);
+}
+
+void page_writer::write(const page *data)
+{
+  m_sink->write_int(data->dlg_id);
+  m_sink->write_int(data->wndproc_id);
+
+#ifdef NSIS_SUPPORT_CODECALLBACKS
+  m_sink->write_int(data->prefunc);
+  m_sink->write_int(data->showfunc);
+  m_sink->write_int(data->leavefunc);
+#endif //NSIS_SUPPORT_CODECALLBACKS
+
+  m_sink->write_int(data->flags);
+
+  m_sink->write_int(data->caption);
+  m_sink->write_int(data->back);
+  m_sink->write_int(data->next);
+  m_sink->write_int(data->clicknext);
+  m_sink->write_int(data->cancel);
+
+  m_sink->write_int_array(data->parms, 5);
+}
+
+void ctlcolors_writer::write(const ctlcolors *data)
+{
+  m_sink->write_int(data->text);
+  m_sink->write_int(data->bkc);
+  m_sink->write_int(data->lbStyle);
+  m_sink->write_int((int) data->bkb);
+  m_sink->write_int(data->bkmode);
+  m_sink->write_int(data->flags);
+}
+
+void LOGFONT_writer::write(const LOGFONT *data)
+{
+  m_sink->write_int(data->lfHeight);
+  m_sink->write_int(data->lfWidth);
+  m_sink->write_int(data->lfEscapement);
+  m_sink->write_int(data->lfOrientation);
+  m_sink->write_int(data->lfWeight);
+  m_sink->write_byte(data->lfItalic);
+  m_sink->write_byte(data->lfUnderline);
+  m_sink->write_byte(data->lfStrikeOut);
+  m_sink->write_byte(data->lfCharSet);
+  m_sink->write_byte(data->lfOutPrecision);
+  m_sink->write_byte(data->lfClipPrecision);
+  m_sink->write_byte(data->lfQuality);
+  m_sink->write_byte(data->lfPitchAndFamily);
+  m_sink->write_string(data->lfFaceName, LF_FACESIZE);
+}
+
+void lang_table_writer::write(const unsigned char *data)
+{
+  assert(sizeof(LANGID) == sizeof(short));
+
+  m_sink->write_short(* (short *) data);
+  data += sizeof(short);
+  m_sink->write_int_array((int *) data, m_lang_strings + 2);
+}
+
+void lang_table_writer::write_block(IGrowBuf *buf, writer_sink *sink, const size_t table_size)
+{
+  unsigned char *tables = (unsigned char *) buf->get();
+  size_t lang_strings = table_size - 2 * sizeof(int) - sizeof(LANGID);
+  size_t l = buf->getlen() / table_size;
+  lang_table_writer writer(sink, lang_strings);
+  for (size_t i = 0; i < l; i++)
+  {
+    writer.write(tables + i * table_size);
+  }
+}
diff --git a/Source/fileform.h b/Source/fileform.h
new file mode 100644
index 00000000..9fc053e9
--- /dev/null
+++ b/Source/fileform.h
@@ -0,0 +1,47 @@
+#ifndef ___MAKENSIS_FILEFORM_H___
+#define ___MAKENSIS_FILEFORM_H___
+
+#include "exehead/fileform.h"
+#include "writer.h"
+
+#define DECLARE_WRITER(x) \
+  class x##_writer : public writer \
+  { \
+  public: \
+    x##_writer(writer_sink *sink) : writer(sink) {} \
+    void write(const x *data); \
+    static void write_block(IGrowBuf *buf, writer_sink *sink) \
+    { \
+      x *arr = (x *) buf->get(); \
+      size_t l = buf->getlen() / sizeof(x); \
+      x##_writer writer(sink); \
+      for (size_t i = 0; i < l; i++) \
+      { \
+        writer.write(&arr[i]); \
+      } \
+    } \
+  }
+
+DECLARE_WRITER(firstheader);
+DECLARE_WRITER(block_header);
+DECLARE_WRITER(header);
+DECLARE_WRITER(section);
+DECLARE_WRITER(entry);
+DECLARE_WRITER(page);
+DECLARE_WRITER(ctlcolors);
+DECLARE_WRITER(LOGFONT);
+
+class lang_table_writer : public writer
+{
+public:
+  lang_table_writer(writer_sink *sink, const size_t lang_strings) :
+    writer(sink), m_lang_strings(lang_strings) {}
+  void write(const unsigned char *data);
+  static void write_block(IGrowBuf *buf, writer_sink *sink, const size_t table_size);
+
+private:
+  size_t m_lang_strings;
+
+};
+
+#endif//!___MAKENSIS_FILEFORM_H___