gnu/build/bootloader.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
   3 ;;;
   4 ;;; This file is part of GNU Guix.
   5 ;;;
   6 ;;; GNU Guix is free software; you can redistribute it and/or modify it
   7 ;;; under the terms of the GNU General Public License as published by
   8 ;;; the Free Software Foundation; either version 3 of the License, or (at
   9 ;;; your option) any later version.
  10 ;;;
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  13 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;;; GNU General Public License for more details.
  15 ;;;
  16 ;;; You should have received a copy of the GNU General Public License
  17 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 (define-module (gnu build bootloader)
  20   #:use-module (ice-9 binary-ports)
  21   #:export (write-file-on-device))
  22
  23 \f
  24 ;;;
  25 ;;; Writing utils.
  26 ;;;
  27
  28 (define (write-file-on-device file size device offset)
  29   "Write SIZE bytes from FILE to DEVICE starting at OFFSET."
  30   (call-with-input-file file
  31     (lambda (input)
  32       (let ((bv (get-bytevector-n input size)))
  33         (call-with-output-file device
  34           (lambda (output)
  35             (seek output offset SEEK_SET)
  36             (put-bytevector output bv))
  37           #:binary #t)))))