From 1305f78d05f4e0027162c1b7e783fc127a49fb8e Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Thu, 19 Dec 2024 16:24:49 +0100 Subject: reconfigure: Support loading the system for kexec reboot. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows rebooting straight into the new system with ‘reboot -k’. * guix/scripts/system/reconfigure.scm (kexec-loading-program) (load-system-for-kexec): New procedures. * gnu/tests/reconfigure.scm (run-kexec-test): New procedure. (%test-upgrade-kexec): New variable. * guix/scripts/system.scm (perform-action): Add #:load-for-kexec?. Call ‘load-system-for-kexec’. (show-help, %options): Add ‘--no-kexec’. (%default-options): Add ‘load-for-kexec?’. (process-action): Honor it and pass it to ‘perform-action’. * gnu/machine/ssh.scm (deploy-managed-host): Add call to ‘load-system-for-kexec’. * doc/guix.texi (Invoking guix system): Document it. Change-Id: I86d11f1c348e4359bc9e73c86e5aebff60fe875c --- doc/guix.texi | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'doc') diff --git a/doc/guix.texi b/doc/guix.texi index da4d2f5ebc..7bf14a49e9 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -43599,11 +43599,20 @@ list-generations}). If that generation already exists, it will be overwritten. This behavior mirrors that of @command{guix package} (@pxref{Invoking guix package}). -It also adds a bootloader menu entry for the new OS configuration, +It adds a bootloader menu entry for the new OS configuration, ---unless @option{--no-bootloader} is passed. For GRUB, it moves entries for older configurations to a submenu, allowing you to choose an older system generation at boot time should you need it. +@cindex kexec, for fast reboots +@cindex rebooting @i{via} Linux kexec +On Linux, @command{guix system reconfigure} also loads the new system +for fast reboot @i{via} kexec: running @command{reboot --kexec} will +boot the new system by directly executing its kernel, thus bypassing the +BIOS initialization phase and bootloader (@pxref{Invoking reboot,,, +shepherd, The GNU Shepherd Manual}). You can avoid this behavior by +passing the @option{--no-kexec} option. + @cindex provenance tracking, of the operating system Upon completion, the new system is deployed under @file{/run/current-system}. This directory contains @dfn{provenance -- cgit v1.2.3