gnu/build/bootloader.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
   3 ;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org>
   4 ;;;
   5 ;;; This file is part of GNU Guix.
   6 ;;;
   7 ;;; GNU Guix is free software; you can redistribute it and/or modify it
   8 ;;; under the terms of the GNU General Public License as published by
   9 ;;; the Free Software Foundation; either version 3 of the License, or (at
  10 ;;; your option) any later version.
  11 ;;;
  12 ;;; GNU Guix is distributed in the hope that it will be useful, but
  13 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;;; GNU General Public License for more details.
  16 ;;;
  17 ;;; You should have received a copy of the GNU General Public License
  18 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 (define-module (gnu build bootloader)
  21   #:use-module (ice-9 binary-ports)
  22   #:export (write-file-on-device))
  23
  24 \f
  25 ;;;
  26 ;;; Writing utils.
  27 ;;;
  28
  29 (define (write-file-on-device file size device offset)
  30   "Write SIZE bytes from FILE to DEVICE starting at OFFSET."
  31   (call-with-input-file file
  32     (lambda (input)
  33       (let ((bv (get-bytevector-n input size)))
  34         (call-with-output-file device
  35           (lambda (output)
  36             (seek output offset SEEK_SET)
  37             (put-bytevector output bv))
  38           #:binary #t)))))