guix-devel/gnu/build/bootloader.scm

38 lines
1.3 KiB
Scheme
Raw Normal View History

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix 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 General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu build bootloader)
#:use-module (ice-9 binary-ports)
#:export (write-file-on-device))
;;;
;;; Writing utils.
;;;
(define (write-file-on-device file size device offset)
"Write SIZE bytes from FILE to DEVICE starting at OFFSET."
(call-with-input-file file
(lambda (input)
(let ((bv (get-bytevector-n input size)))
(call-with-output-file device
(lambda (output)
(seek output offset SEEK_SET)
(put-bytevector output bv))
#:binary #t)))))