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author | Mathieu Othacehe <m.othacehe@gmail.com> | 2017-04-10 19:18:10 +0200 |
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committer | Ludovic Courtès <ludo@gnu.org> | 2017-04-11 11:13:25 +0200 |
commit | 8336df0668e401a724cd61aa83ba4537591aa7bf (patch) | |
tree | 438bad45dccae1d1512a87aa7e7a9cf3947bd489 /guix/build | |
parent | e40335b27547064f0fefb62041fe5aa73f1ad7db (diff) | |
download | gnu-guix-8336df0668e401a724cd61aa83ba4537591aa7bf.tar gnu-guix-8336df0668e401a724cd61aa83ba4537591aa7bf.tar.gz |
syscalls: Add reboot.
* guix/build/syscalls.scm (define-as-needed): New macro.
(reboot): New procedure. Reimplemented from guile-linux-syscalls.patch.
(RB_AUTOBOOT, ..., RB_KEXEC): New flags copied from static Guile patch.
Co-Authored-By: Ludovic Courtès <ludo@gnu.org>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Diffstat (limited to 'guix/build')
-rw-r--r-- | guix/build/syscalls.scm | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index 4bcb2a871c..0de39aee6b 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -2,6 +2,7 @@ ;;; Copyright © 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2015 David Thompson <davet@gnu.org> ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org> +;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com> ;;; ;;; This file is part of GNU Guix. ;;; @@ -149,8 +150,19 @@ ;;; Commentary: ;;; ;;; This module provides bindings to libc's syscall wrappers. It uses the -;;; FFI, and thus requires a dynamically-linked Guile. (For statically-linked -;;; Guile, we instead apply 'guile-linux-syscalls.patch'.) +;;; FFI, and thus requires a dynamically-linked Guile. +;;; +;;; Some syscalls are already defined in statically-linked Guile by applying +;;; 'guile-linux-syscalls.patch'. +;;; +;;; Visibility of syscall's symbols shared between this module and static Guile +;;; is a bit delicate. It is handled by 'define-as-needed' macro. +;;; +;;; This macro is used to export symbols in dynamic Guile context, and to +;;; re-export them in static Guile context. +;;; +;;; This way, even if they don't appear in #:export list, it is safe to use +;;; syscalls from this module in static or dynamic Guile context. ;;; ;;; Code: @@ -409,6 +421,25 @@ the returned procedure is called." (error (format #f "~a: syscall->procedure failed: ~s" name args)))))) +(define-syntax define-as-needed + (syntax-rules () + "Define VARIABLE. If VARIABLE already exists in (guile) then re-export it, + otherwise export the newly-defined VARIABLE." + ((_ (proc args ...) body ...) + (define-as-needed proc (lambda* (args ...) body ...))) + ((_ variable value) + (begin + (when (module-defined? the-scm-module 'variable) + (re-export variable)) + + (define variable + (if (module-defined? the-scm-module 'variable) + (module-ref the-scm-module 'variable) + value)) + + (unless (module-defined? the-scm-module 'variable) + (export variable)))))) + ;;; ;;; File systems. @@ -547,6 +578,22 @@ constants from <sys/mount.h>." (list device (strerror err)) (list err))))))) +(define-as-needed RB_AUTOBOOT #x01234567) +(define-as-needed RB_HALT_SYSTEM #xcdef0123) +(define-as-needed RB_ENABLED_CAD #x89abcdef) +(define-as-needed RB_DISABLE_CAD 0) +(define-as-needed RB_POWER_OFF #x4321fedc) +(define-as-needed RB_SW_SUSPEND #xd000fce2) +(define-as-needed RB_KEXEC #x45584543) + +(define-as-needed (reboot #:optional (cmd RB_AUTOBOOT)) + (let ((proc (syscall->procedure int "reboot" (list int)))) + (let-values (((ret err) (proc cmd))) + (unless (zero? ret) + (throw 'system-error "reboot" "~S: ~A" + (list cmd (strerror err)) + (list err)))))) + (define (kernel? pid) "Return #t if PID designates a \"kernel thread\" rather than a normal user-land process." |