diff options
Diffstat (limited to 'module/language/objcode')
-rw-r--r-- | module/language/objcode/elf.scm | 94 | ||||
-rw-r--r-- | module/language/objcode/spec.scm | 1 |
2 files changed, 95 insertions, 0 deletions
diff --git a/module/language/objcode/elf.scm b/module/language/objcode/elf.scm new file mode 100644 index 000000000..9654c0861 --- /dev/null +++ b/module/language/objcode/elf.scm @@ -0,0 +1,94 @@ +;;; Embedding bytecode in ELF + +;; Copyright (C) 2012 Free Software Foundation, Inc. + +;;;; This library is free software; you can redistribute it and/or +;;;; modify it under the terms of the GNU Lesser General Public +;;;; License as published by the Free Software Foundation; either +;;;; version 3 of the License, or (at your option) any later version. +;;;; +;;;; This library is distributed in the hope that it will be useful, +;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;;;; Lesser General Public License for more details. +;;;; +;;;; You should have received a copy of the GNU Lesser General Public +;;;; License along with this library; if not, write to the Free Software +;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + +;;; Code: + +;; The eval-when is because (language objcode elf) will not be loaded +;; yet when we go to compile it, but later passes of the +;; compiler need it. So we have to be sure that the module is present +;; at compile time, with all of its definitions. The easiest way to do +;; that is just to go ahead and resolve it now. +;; +(define-module (language objcode elf) + #:use-module (system vm objcode) + #:use-module (system base target) + #:use-module (rnrs bytevectors) + #:use-module (ice-9 binary-ports) + #:use-module (system vm elf) + #:export (write-objcode)) + +(define (bytecode->elf bv) + (let ((string-table (make-elf-string-table))) + (define (intern-string! string) + (call-with-values + (lambda () (elf-string-table-intern string-table string)) + (lambda (table idx) + (set! string-table table) + idx))) + (define (make-object name bv relocs . kwargs) + (let ((name-idx (intern-string! (symbol->string name)))) + (make-elf-object (apply make-elf-section + #:name name-idx + #:size (bytevector-length bv) + kwargs) + bv relocs + (list (make-elf-symbol name 0))))) + (define (make-dynamic-section word-size endianness) + (define (make-dynamic-section/32) + (let ((bv (make-bytevector 24 0))) + (bytevector-u32-set! bv 0 DT_GUILE_RTL_VERSION endianness) + (bytevector-u32-set! bv 4 #x02000000 endianness) + (bytevector-u32-set! bv 8 DT_GUILE_ENTRY endianness) + (bytevector-u32-set! bv 12 0 endianness) + (bytevector-u32-set! bv 16 DT_NULL endianness) + (bytevector-u32-set! bv 20 0 endianness) + (values bv (make-elf-reloc 'abs32/1 12 0 '.rtl-text)))) + (define (make-dynamic-section/64) + (let ((bv (make-bytevector 48 0))) + (bytevector-u64-set! bv 0 DT_GUILE_RTL_VERSION endianness) + (bytevector-u64-set! bv 8 #x02000000 endianness) + (bytevector-u64-set! bv 16 DT_GUILE_ENTRY endianness) + (bytevector-u64-set! bv 24 0 endianness) + (bytevector-u64-set! bv 32 DT_NULL endianness) + (bytevector-u64-set! bv 40 0 endianness) + (values bv (make-elf-reloc 'abs64/1 24 0 '.rtl-text)))) + (call-with-values (lambda () + (case word-size + ((4) (make-dynamic-section/32)) + ((8) (make-dynamic-section/64)) + (else (error "unexpected word size" word-size)))) + (lambda (bv reloc) + (make-object '.dynamic bv (list reloc) + #:type SHT_DYNAMIC #:flags SHF_ALLOC)))) + (define (link-string-table) + (intern-string! ".shstrtab") + (make-object '.shstrtab (link-elf-string-table string-table) '() + #:type SHT_STRTAB #:flags 0)) + (let* ((word-size (target-word-size)) + (endianness (target-endianness)) + (text (make-object '.rtl-text bv '())) + (dt (make-dynamic-section word-size endianness)) + ;; This needs to be linked last, because linking other + ;; sections adds entries to the string table. + (shstrtab (link-string-table))) + (link-elf (list text dt shstrtab) + #:endianness endianness #:word-size word-size)))) + +(define (write-objcode objcode port) + (let ((bv (objcode->bytecode objcode (target-endianness)))) + (put-bytevector port (bytecode->elf bv)))) diff --git a/module/language/objcode/spec.scm b/module/language/objcode/spec.scm index 7cc85b7f6..022419e9d 100644 --- a/module/language/objcode/spec.scm +++ b/module/language/objcode/spec.scm @@ -22,6 +22,7 @@ #:use-module (system base language) #:use-module (system vm objcode) #:use-module (system vm program) + #:use-module (language objcode elf) #:export (objcode)) (define (objcode->value x e opts) |