Subject: [PATCH v4 11/15] gnu: bootloaders: Add uki-efi-bootloader.

From: Lilah Tascheter <[email-masked]>
Date: Mon, 5 Aug 2024 21:44:49 -0500

* gnu/bootloader.scm (<bootloader-configuration>): New keypair field.
* gnu/bootloader/uki.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add bootloader/uki.scm.

Change-Id: I2097da9f3dd35137b3419f6d0545de26d53cb6da
---
 gnu/bootloader.scm     |  3 ++
 gnu/bootloader/uki.scm | 96 ++++++++++++++++++++++++++++++++++++++++++
 gnu/local.mk           |  1 +
 3 files changed, 100 insertions(+)
 create mode 100644 gnu/bootloader/uki.scm

diff --git a/gnu/bootloader.scm b/gnu/bootloader.scm
index 9fb2accfd2..e261b38e71 100644
--- a/gnu/bootloader.scm
+++ b/gnu/bootloader.scm
@@ -101,6 +101,7 @@ (define-module (gnu bootloader)
             bootloader-configuration-default-entry
             bootloader-configuration-efi-removable?
             bootloader-configuration-32bit?
+            bootloader-configuration-keypair
             bootloader-configuration-timeout
             bootloader-configuration-keyboard-layout
             bootloader-configuration-theme
@@ -526,6 +527,8 @@ (define-record-type* <bootloader-configuration>
                          (default #f))    ;bool
   (32bit?                bootloader-configuration-32bit?
                          (default #f))    ;bool
+  (keypair               bootloader-configuration-keypair
+                         (default #f))    ;(cert . priv) pair
   (timeout               bootloader-configuration-timeout
                          (default 5))     ;seconds as integer
   (keyboard-layout       bootloader-configuration-keyboard-layout
diff --git a/gnu/bootloader/uki.scm b/gnu/bootloader/uki.scm
new file mode 100644
index 0000000000..4871dbe037
--- /dev/null
+++ b/gnu/bootloader/uki.scm
@@ -0,0 +1,96 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2024 Lilah Tascheter <[email-masked]>
+;;;
+;;; 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 bootloader uki)
+  #:use-module (gnu bootloader)
+  #:use-module (gnu packages bootloaders)
+  #:use-module (gnu packages efi)
+  #:use-module (gnu packages linux)
+  #:use-module (gnu system boot)
+  #:use-module (guix gexp)
+  #:use-module (guix diagnostics)
+  #:use-module (guix i18n)
+  #:use-module (guix records)
+  #:export (uki-efi-bootloader))
+
+;; TODO: support 32bit/mixed-mode UEFI.
+;; https://github.com/systemd/systemd/issues/17056 may be relevant
+(define bootcfg->menu-entry->builder
+  (match-record-lambda <bootloader-configuration> (32bit? theme keypair)
+    (match-record-lambda <menu-entry>
+      (label linux linux-arguments initrd chain-loader)
+      ;; support chainloader in order to allow arbitrary signed EFI binaries
+      (cond
+        ((and chain-loader keypair)
+         #~(lambda (dest)
+             (invoke/quiet #+(sbsigntools "/bin/sbsign")
+               "--cert" #$(car keypair) "--key" #$(cdr keypair)
+               "--output" dest #$chain-loader)
+             (invoke/quiet #+(sbsigntools "/bin/sbverify")
+               "--cert" #$(car keypair) dest)))
+        (chain-loader #~(lambda (dest) (copy-file #$chain-loader dest)))
+        (linux
+          (let* ((arch (efi-arch #:32? 32bit?))
+                 (stub (file-append systemd-stub
+                         "/libexec/linux" arch ".efi.stub")))
+            #~(lambda (dest)
+                (invoke/quiet #+(file-append ukify "/bin/ukify")
+                  "build" "--output" dest
+                  "--linux" #$linux "--initrd" #$initrd
+                  "--cmdline" (string-join (list #$@linux-arguments))
+                  "--os-release" #$label "--stub" #$stub "--efi-arch" #$arch
+                  #$@(if theme #~("--splash" #$theme) '())
+                  #$@(if keypair #~("--secureboot-certificate" #$(car keypair)
+                                    "--secureboot-private-key" #$(cdr keypair))
+                                 '())))))
+        (else (leave (G_ "uki-efi-bootloader doesn't support multiboot")))))))
+
+;; we cannot use guix's build system to make UKI images for two reasons:
+;; 1. signing is necessarily non-reproducable, especially since keys should not
+;;    be in the store, or else risk being publically accessible.
+;; 2. menu-entries may reference files which do not exist in the store.
+(define* (install-uki #:key bootloader-config
+                            current-boot-alternative
+                            old-boot-alternatives
+                      #:allow-other-keys)
+  (define* (menu-entry->plan entry num #:optional (prefix "menu-entry"))
+    #~(cons* #$((bootcfg->menu-entry->builder bootloader-config) entry)
+             #$(string-append prefix "-" (number->string num) ".efi")
+             #$(menu-entry-label entry)))
+
+  (define (boot-alternative->plan alt)
+    (menu-entry->plan (boot-alternative->menu-entry alt)
+                      (boot-alternative-generation alt)
+                      "generation"))
+
+  (install-efi bootloader-config
+    (let ((entries (bootloader-configuration-menu-entries bootloader-config)))
+      #~(list #$(boot-alternative->plan current-boot-alternative)
+              #$@(map menu-entry->plan entries (iota (length entries)))
+              #$@(map boot-alternative->plan old-boot-alternatives)))))
+
+
+
+(define uki-efi-bootloader
+  (bootloader
+    (name 'uki-efi)
+    (default-targets (list (bootloader-target
+                             (type 'vendir)
+                             (offset 'esp)
+                             (path "EFI/Guix"))))
+    (installer install-uki)))
diff --git a/gnu/local.mk b/gnu/local.mk
index 8375e13709..32ed753ee2 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -93,6 +93,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/bootloader/extlinux.scm                   \
   %D%/bootloader/u-boot.scm                     \
   %D%/bootloader/depthcharge.scm                \
+  %D%/bootloader/uki.scm                        \
   %D%/ci.scm					\
   %D%/compression.scm				\
   %D%/home.scm					\
-- 
2.45.2