From c85f316ae986331cc5181da4bcc757078d7a9412 Mon Sep 17 00:00:00 2001 From: Stefan Date: Sat, 26 Sep 2020 12:54:00 +0200 Subject: gnu: grub: Support for network boot via TFTP. * gnu/bootloader/grub.scm (grub-efi-netboot-bootloader): New variable. (install-grub-efi-netboot): New procedure. (grub-root-search): Update comment. Signed-off-by: Danny Milosavljevic --- gnu/bootloader/grub.scm | 114 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 110 insertions(+), 4 deletions(-) (limited to 'gnu/bootloader') diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm index f69bf8ed4d..516a7d48c8 100644 --- a/gnu/bootloader/grub.scm +++ b/gnu/bootloader/grub.scm @@ -23,8 +23,10 @@ ;;; along with GNU Guix. If not, see . (define-module (gnu bootloader grub) + #:use-module (guix build union) #:use-module (guix records) - #:use-module ((guix utils) #:select (%current-system)) + #:use-module (guix store) + #:use-module (guix utils) #:use-module (guix gexp) #:use-module (gnu artwork) #:use-module (gnu bootloader) @@ -46,8 +48,11 @@ grub-theme-color-highlight grub-theme-gfxmode + install-grub-efi-netboot + grub-bootloader grub-efi-bootloader + grub-efi-netboot-bootloader grub-mkrescue-bootloader grub-minimal-bootloader @@ -297,9 +302,11 @@ code." (file-system-label->string label))) ((? (lambda (device) (and (string? device) (string-contains device ":/"))) nfs-uri) - ;; This assumes that if your root file system is on NFS, then - ;; you also want to load your grub extra files, kernel and initrd - ;; from there. + ;; If the device is an NFS share, then we assume that the expected + ;; file on that device (e.g. the GRUB background image or the kernel) + ;; has to be loaded over the network. Otherwise we would need an + ;; additional device information for some local disk to look for that + ;; file, which we do not have. ;; ;; We explicitly set "root=(tftp)" here even though if grub.cfg ;; had been loaded via TFTP, Grub would have set "root=(tftp)" @@ -528,6 +535,99 @@ fi~%")))) "--bootloader-id=Guix" "--efi-directory" target-esp)))) +(define (install-grub-efi-netboot subdir) + "Define a grub-efi-netboot bootloader installer for installation in SUBDIR, +which is usually efi/Guix or efi/boot." + (let* ((system (string-split (nix-system->gnu-triplet + (or (%current-target-system) + (%current-system))) + #\-)) + (arch (first system)) + (boot-efi-link (match system + ;; These are the supportend systems and the names + ;; defined by the UEFI standard for removable media. + (("i686" _ ...) "/bootia32.efi") + (("x86_64" _ ...) "/bootx64.efi") + (("arm" _ ...) "/bootarm.efi") + (("aarch64" _ ...) "/bootaa64.efi") + (("riscv" _ ...) "/bootriscv32.efi") + (("riscv64" _ ...) "/bootriscv64.efi") + ;; Other systems are not supported, although defined. + ;; (("riscv128" _ ...) "/bootriscv128.efi") + ;; (("ia64" _ ...) "/bootia64.efi") + ((_ ...) #f))) + (core-efi (string-append + ;; This is the arch dependent file name of GRUB, e.g. + ;; i368-efi/core.efi or arm64-efi/core.efi. + (match arch + ("i686" "i386") + ("aarch64" "arm64") + ("riscv" "riscv32") + (_ arch)) + "-efi/core.efi"))) + (with-imported-modules + '((guix build union)) + #~(lambda (bootloader target mount-point) + "Install the BOOTLOADER, which must be the package grub, as e.g. +bootx64.efi or bootaa64.efi into SUBDIR, which is usually efi/Guix or efi/boot, +below the directory TARGET for the system whose root is mounted at MOUNT-POINT. + +MOUNT-POINT is the last argument in 'guix system init /etc/config.scm mnt/point' +or '/' for other 'guix system' commands. + +TARGET is the target argument given to the bootloader-configuration in + +(operating-system + (bootloader (bootloader-configuration + (target \"/boot\") + …)) + …) + +TARGET is required to be an absolute directory name, usually mounted via NFS, +and finally needs to be provided by a TFTP server as the TFTP root directory. + +GRUB will load tftp://server/SUBDIR/grub.cfg and this file will instruct it to +load more files from the store like tftp://server/gnu/store/…-linux…/Image. + +To make this possible two symlinks will be created. The first symlink points +relatively form MOUNT-POINT/TARGET/SUBDIR/grub.cfg to +MOUNT-POINT/boot/grub/grub.cfg, and the second symlink points relatively from +MOUNT-POINT/TARGET/%store-prefix to MOUNT-POINT/%store-prefix. + +It is important to note that these symlinks need to be relativ, as the absolute +paths on the TFTP server side are unknown. + +It is also important to note that both symlinks will point outside the TFTP root +directory and that the TARGET/%store-prefix symlink makes the whole store +accessible via TFTP. Possibly the TFTP server must be configured +to allow accesses outside its TFTP root directory. This may need to be +considered for security aspects." + (use-modules ((guix build union) #:select (symlink-relative))) + (let* ((net-dir (string-append mount-point target "/")) + (sub-dir (string-append net-dir #$subdir "/")) + (store (string-append mount-point (%store-prefix))) + (store-link (string-append net-dir (%store-prefix))) + (grub-cfg (string-append mount-point "/boot/grub/grub.cfg")) + (grub-cfg-link (string-append sub-dir (basename grub-cfg))) + (boot-efi-link (string-append sub-dir #$boot-efi-link))) + ;; Prepare the symlink to the store. + (mkdir-p (dirname store-link)) + (false-if-exception (delete-file store-link)) + (symlink-relative store store-link) + ;; Prepare the symlink to the grub.cfg, which points into the store. + (mkdir-p (dirname grub-cfg-link)) + (false-if-exception (delete-file grub-cfg-link)) + (symlink-relative grub-cfg grub-cfg-link) + ;; Install GRUB, which refers to the grub.cfg, with support for + ;; encrypted partitions, + (setenv "GRUB_ENABLE_CRYPTODISK" "y") + (invoke/quiet (string-append bootloader "/bin/grub-mknetdir") + (string-append "--net-directory=" net-dir) + (string-append "--subdir=" #$subdir)) + ;; Prepare the bootloader symlink, which points to core.efi of GRUB. + (false-if-exception (delete-file boot-efi-link)) + (symlink #$core-efi boot-efi-link)))))) + ;;; @@ -560,6 +660,12 @@ fi~%")))) (name 'grub-efi) (package grub-efi))) +(define grub-efi-netboot-bootloader + (bootloader + (inherit grub-efi-bootloader) + (name 'grub-efi-netboot-bootloader) + (installer (install-grub-efi-netboot "efi/Guix")))) + (define grub-mkrescue-bootloader (bootloader (inherit grub-efi-bootloader) -- cgit v1.2.3