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diff --git a/proto/elf.ml b/proto/elf.ml
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--- /dev/null
+++ b/proto/elf.ml
@@ -0,0 +1,200 @@
+(* This is a module to spit simple ELF
+   object files that can afterwards be
+   linked to build an application.
+*)
+
+let hash s =
+  (* The ELF hash function. *)
+  let open Int64 in (* I doubt this is necessary... *)
+  let rec f p h =
+    if p = String.length s then to_int h else
+    let h = shift_left h 4 in
+    let h = add h (of_int (int_of_char s.[p])) in
+    let g = logand h (of_int 0xf0000000) in
+    let h = logxor h (shift_right g 24) in
+    f (p+1) (logand h (of_int 0x0fffffff)) in
+  f 0 (of_int 0)
+
+let le n x =
+  (* Make a string of bytes in little endian convention. *)
+  let b = Bytes.create n in
+  let rec f i x =
+    if i = n then () else
+    let d = char_of_int (x land 0xff) in
+    Bytes.set b i d;
+    f (i+1) (x lsr 8) in
+  f 0 x; Bytes.to_string b
+
+let stt_NOTYPE = 0
+let stt_OBJECT = 1
+let stt_FUNC   = 2
+
+let stb_LOCAL  = 0
+let stb_GLOBAL = 16
+let stb_WEAK   = 32
+
+let sht_NULL     = le 4 0
+let sht_PROGBITS = le 4 1
+let sht_SYMTAB   = le 4 2
+let sht_STRTAB   = le 4 3
+let sht_RELA     = le 4 4
+let sht_NOTE     = le 4 7
+let sht_NOBITS   = le 4 8
+
+let shf_WRITE     = 1
+let shf_ALLOC     = 2
+let shf_EXECINSTR = 4
+
+let barebones_elf oc fn text =
+  let header = String.concat ""
+    [ "\x7fELF"                          (* e_ident, magic *)
+    ; "\x02"                             (* e_ident, ELFCLASS64 *)
+    ; "\x01"                             (* e_ident, ELFDATA2LSB *)
+    ; "\x01"                             (* e_indent, EV_CURRENT *)
+    ; "\x00"                             (* e_ident, ELFOSABI_SYSV *)
+    ; "\x00"                             (* e_ident, ABI version *)
+    ; "\x00\x00\x00\x00\x00\x00\x00"     (* e_ident, padding *)
+    ; "\x01\x00"                         (* e_type, ET_REL *)
+    ; "\x3e\x00"                         (* e_machine, EM_X86_64 *)
+    ; "\x01\x00\x00\x00"                 (* e_version, EV_CURRENT *)
+    ; "\x00\x00\x00\x00\x00\x00\x00\x00" (* e_entry, unused *)
+    ; "\x00\x00\x00\x00\x00\x00\x00\x00" (* e_phoff, unused *)
+    ; "\x40\x00\x00\x00\x00\x00\x00\x00" (* e_shoff, 64 *)
+    ; "\x00\x00\x00\x00"                 (* e_flags, 0 *)
+    ; "\x40\x00"                         (* e_hsize, 64 *)
+    ; "\x00\x00"                         (* e_phentsize, 0 *)
+    ; "\x00\x00"                         (* e_phnum, 0 *)
+    ; "\x40\x00"                         (* e_shentsize, 64 *)
+    ; "\x07\x00"                         (* e_shnum, 7 *)
+    ; "\x06\x00"                         (* e_shstrndx, 6 *)
+    ] in
+
+  (* We will use the following section organization.
+     1- .text   PROGBITS
+     2- .data   PROGBITS
+     3- .bss    NOBITS
+     4- .rela   RELA
+     5- .symtab SYMTAB
+     6- .strtab STRTAB
+  *)
+
+  let adds s x = (String.length s, s ^ x ^ "\x00") in
+  (* section names *)
+  let textstr, strtab = adds "\x00" ".text" in
+  let datastr, strtab = adds strtab ".data" in
+  let bssstr , strtab = adds strtab ".bss"  in
+  let relastr, strtab = adds strtab ".rela" in
+  let symtstr, strtab = adds strtab ".symt" in
+  let strtstr, strtab = adds strtab ".strt" in
+  (* function names *)
+  let fnstr, strtab = adds strtab fn in
+
+  let symtab = String.concat ""
+    [ le 0x18 0                      (* first symbol is reserved *)
+    ; le 4 fnstr                     (* st_name *)
+    ; le 1 (stt_FUNC lor stb_GLOBAL) (* st_info *)
+    ; "\x00"                         (* st_other *)
+    ; le 2 1                         (* st_shndx, .text *)
+    ; le 8 0                         (* st_value, offset in .text section *)
+    ; le 8 (String.length text)      (* st_size *)
+    ] in
+
+  let textoff = 64 + 7 * 64 in
+  let txtlen, txtpad =
+    let l = String.length text in
+    let p = (l + 7) land 7 in
+    (l, p) in
+  let dataoff = textoff + txtlen + txtpad in
+  let bssoff  = dataoff + 0 in
+  let relaoff = bssoff + 0 in
+  let symtoff = relaoff + 0 in
+  let strtoff = symtoff + String.length symtab in
+
+  let sh = String.concat ""
+    [ le 64 0 (* first section header is reserved *)
+    (* .text *)
+    ; le 4 textstr                   (* sh_name *)
+    ; sht_PROGBITS                   (* sh_type *)
+    ; le 8 (shf_ALLOC lor shf_EXECINSTR) (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 textoff                   (* sh_offset *)
+    ; le 8 txtlen                    (* sh_size *)
+    ; le 4 0                         (* sh_link *)
+    ; le 4 0                         (* sh_info *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0                         (* sh_entsize *)
+    (* .data *)
+    ; le 4 datastr                   (* sh_name *)
+    ; sht_PROGBITS                   (* sh_type *)
+    ; le 8 (shf_ALLOC lor shf_WRITE) (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 dataoff                   (* sh_offset *)
+    ; le 8 0                         (* sh_size *)
+    ; le 4 0                         (* sh_link *)
+    ; le 4 0                         (* sh_info *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0                         (* sh_entsize *)
+    (* .bss *)
+    ; le 4 bssstr                    (* sh_name *)
+    ; sht_NOBITS                     (* sh_type *)
+    ; le 8 (shf_ALLOC lor shf_WRITE) (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 bssoff                    (* sh_offset *)
+    ; le 8 0                         (* sh_size *)
+    ; le 4 0                         (* sh_link *)
+    ; le 4 0                         (* sh_info *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0                         (* sh_entsize *)
+    (* .rela *)
+    ; le 4 relastr                   (* sh_name *)
+    ; sht_RELA                       (* sh_type *)
+    ; le 8 0                         (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 relaoff                   (* sh_offset *)
+    ; le 8 0                         (* sh_size *)
+    ; le 4 5                         (* sh_link, symtab index *)
+    ; le 4 1                         (* sh_info, text section *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0x18                      (* sh_entsize *)
+    (* .symtab *)
+    ; le 4 symtstr                   (* sh_name *)
+    ; sht_SYMTAB                     (* sh_type *)
+    ; le 8 0                         (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 symtoff                   (* sh_offset *)
+    ; le 8 (String.length symtab)    (* sh_size *)
+    ; le 4 6                         (* sh_link, strtab index *)
+    ; le 4 1                         (* sh_info, first non-local symbol *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0x18                      (* sh_entsize *)
+    (* .strtab *)
+    ; le 4 strtstr                   (* sh_name *)
+    ; sht_STRTAB                     (* sh_type *)
+    ; le 8 0                         (* sh_flags *)
+    ; le 8 0                         (* sh_addr *)
+    ; le 8 strtoff                   (* sh_offset *)
+    ; le 8 (String.length strtab)    (* sh_size *)
+    ; le 4 0                         (* sh_link *)
+    ; le 4 0                         (* sh_info *)
+    ; le 8 1                         (* sh_addralign *)
+    ; le 8 0x18                      (* sh_entsize *)
+    ] in
+
+  List.iter (output_string oc)
+    [ header
+    ; sh
+    ; text; String.make txtpad '\x90'
+    ; symtab
+    ; strtab
+    ]
+
+
+(*
+let _ =
+  let oc = open_out "test.o" in
+  let text = String.concat ""
+    [ "\xb8\x2a\x00\x00\x00" (* mov 42, %eax *)
+    ; "\xc3"                 (* retq *)
+    ] in
+  barebones_elf oc "main" text
+*)