From cbeba372def25a957f5d8942f01fbde6cdc03704 Mon Sep 17 00:00:00 2001 From: Reza Alizadeh Majd Date: Sun, 28 Aug 2022 12:34:46 +0430 Subject: [PATCH] bootloader: extlinux: support for optional FDTDIR There are situations that u-boot doesn't have to load from the device tree. some provide the device tree using a vendor bootloader (like what raspberry-pi does) or with an external bootloader that chainloads the u-boot (what Asahi does for m1n1 bootloader). Unfortunately we couldn't find any reliable document to enforce u-boot to pass the device tree via `extlinux.conf`, however during our tests, we found that removing the `FDTDIR` line from the `extlinux.conf` tend us to do so. There is also no reliable way to guess if u-boot bootloader should load device tree or not on a specific hardware. in addition, there are hardware that can be booted with both firmware device tree on some kernels and with special device tree on other (modified) kernels. the following changes provided to define an optional parameter in record, called which by default is set to #t to keep the current behavior unchanged. if this paramter is set to #f, the FDTDIR line will be discarded from the and u-boot doesn't load the device tree automatically. * gnu/bootloader.scm ()[device-tree-support?]: new field. * gnu/bootloader/extlinux.scm (extlinux-configuration-file): add FDTDIR line based on bootloader field of . * doc/guix.texi (Bootloader Configuration)[bootloader]: Add note about bootloader's optional FDTDIR support. --- doc/guix.texi | 9 +++++++++ gnu/bootloader.scm | 6 +++++- gnu/bootloader/extlinux.scm | 13 +++++++++++-- 3 files changed, 25 insertions(+), 3 deletions(-) diff --git a/doc/guix.texi b/doc/guix.texi index 023b48ae35..25b336e958 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -36814,6 +36814,15 @@ modules. In particular, @code{(gnu bootloader u-boot)} contains definitions of bootloaders for a wide range of ARM and AArch64 systems, using the @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}. +@quotation Note +There are situations when @code{u-boot} shouldn't load the device tree from +the file system. because it is either unnecessary for the platform being used +or has already been loaded into RAM earlier in the boot process. in such cases +you can set the @code{device-tree-support?} field of the @code{bootloader} +record to @code{#f}. setting this flag to @code{#f} removes the @code{FDTDIR} +from the @file{/boot/extlinux/extlinux.conf}. +@end quotation + @vindex grub-efi-bootloader @code{grub-efi-bootloader} allows to boot on modern systems using the @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should diff --git a/gnu/bootloader.scm b/gnu/bootloader.scm index 70e1836179..32fd7f0c2e 100644 --- a/gnu/bootloader.scm +++ b/gnu/bootloader.scm @@ -4,6 +4,7 @@ ;;; Copyright © 2017 Leo Famulari ;;; Copyright © 2019, 2021 Ludovic Courtès ;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen +;;; Copyright © 2022 Reza Alizadeh Majd ;;; ;;; This file is part of GNU Guix. ;;; @@ -54,6 +55,7 @@ (define-module (gnu bootloader) bootloader-disk-image-installer bootloader-configuration-file bootloader-configuration-file-generator + bootloader-device-tree-support? bootloader-configuration bootloader-configuration? @@ -172,7 +174,9 @@ (define-record-type* (disk-image-installer bootloader-disk-image-installer (default #f)) (configuration-file bootloader-configuration-file) - (configuration-file-generator bootloader-configuration-file-generator)) + (configuration-file-generator bootloader-configuration-file-generator) + (device-tree-support? bootloader-device-tree-support? + (default #t))) ;;; diff --git a/gnu/bootloader/extlinux.scm b/gnu/bootloader/extlinux.scm index 6b5ff298e7..f3d69c0cc0 100644 --- a/gnu/bootloader/extlinux.scm +++ b/gnu/bootloader/extlinux.scm @@ -1,6 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2017 David Craven ;;; Copyright © 2017 Mathieu Othacehe +;;; Copyright © 2022 Reza Alizadeh Majd ;;; ;;; This file is part of GNU Guix. ;;; @@ -38,6 +39,10 @@ (define* (extlinux-configuration-file config entries (define all-entries (append entries (bootloader-configuration-menu-entries config))) + (define with-fdtdir? + (let ((bootloader (bootloader-configuration-bootloader config))) + (bootloader-device-tree-support? bootloader))) + (define (menu-entry->gexp entry) (let ((label (menu-entry-label entry)) (kernel (menu-entry-linux entry)) @@ -46,12 +51,16 @@ (define (menu-entry->gexp entry) #~(format port "LABEL ~a MENU LABEL ~a KERNEL ~a - FDTDIR ~a/lib/dtbs + ~a INITRD ~a APPEND ~a ~%" #$label #$label - #$kernel (dirname #$kernel) #$initrd + #$kernel + (if #$with-fdtdir? + (string-append "FDTDIR " (dirname #$kernel) "/lib/dtbs") + "") + #$initrd (string-join (list #$@kernel-arguments))))) (define builder -- 2.37.1