From 50062572301d6653d8c2574eadb0bed460d25322 Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Tue, 30 Mar 2021 22:39:22 +0200
Subject: [PATCH] Put boot image into ESP

---
 nixos-modules/lib/make-bootable-image.nix |  6 ++--
 nixos-modules/lib/make-esp-fs.nix         | 40 +++++++++++++++++------
 nixos-modules/lib/make-ext2-fs.nix        | 24 ++------------
 3 files changed, 37 insertions(+), 33 deletions(-)

diff --git a/nixos-modules/lib/make-bootable-image.nix b/nixos-modules/lib/make-bootable-image.nix
index 9d9c260..f6056e7 100644
--- a/nixos-modules/lib/make-bootable-image.nix
+++ b/nixos-modules/lib/make-bootable-image.nix
@@ -10,6 +10,8 @@ pkgs.stdenv.mkDerivation {
     zstd
   ];
 
+  inherit espImage;
+
   buildCommand = ''
     img=./temp.raw
     blockSize=512
@@ -24,8 +26,8 @@ pkgs.stdenv.mkDerivation {
     truncate --size=$esbByteOffset $img
 
     # Concatentenate the ESP
-    echo "Concatenate ESP ${espImage}"
-    zstdcat ${espImage} >> $img
+    echo "Concatenate ESP $espImage"
+    zstdcat $espImage >> $img
 
     imgBytes=$(stat --format=%s $img)
     echo "Image is $(( $imgBytes >> 20 )) MiB with ESP partition"
diff --git a/nixos-modules/lib/make-esp-fs.nix b/nixos-modules/lib/make-esp-fs.nix
index 4e8233c..66616f0 100644
--- a/nixos-modules/lib/make-esp-fs.nix
+++ b/nixos-modules/lib/make-esp-fs.nix
@@ -23,29 +23,32 @@ in pkgs.stdenv.mkDerivation {
     "configfile"
     "efi_gop"
     "efi_uga"
-    "ext2"
+    "fat"
     "gzio"
     "multiboot"
     "multiboot2"
     "normal"
     "part_gpt"
-    "search_fs_uuid"
+    "search"
   ];
 
   buildCommand = ''
     img=tmp.raw
-    bootdir=EFI/boot/
-    mkdir -p $bootdir
+    bootdir=./espRoot/boot/
+    grubdir=./espRoot/boot/grub
+    efidir=./espRoot/EFI/boot
+
+    mkdir -p $bootdir $efidir $grubdir
 
     cat <<EOF > embedded.cfg
     insmod configfile
     insmod efi_gop
     insmod efi_uga
-    insmod ext2
+    insmod fat
     insmod normal
     insmod part_gpt
     insmod search_fs_uuid
-    search.fs_uuid ${config.genode.boot.storeFsUuid} root
+    search --set=root --label EFIBOOT
     set prefix=($root)/boot/grub
     configfile /boot/grub/grub.cfg
     EOF
@@ -54,17 +57,34 @@ in pkgs.stdenv.mkDerivation {
 
     ${grub'}/bin/grub-mkimage \
       --config=embedded.cfg \
-      --output=$bootdir/boot${targetArch}.efi \
-      --prefix=/boot/grub \
+      --output=$efidir/boot${targetArch}.efi \
+      --prefix=/sigil/grub \
       --format=${grub'.grubTarget} \
       $MODULES
 
+    cat > extraPrepareConfig.sh <<< '${config.boot.loader.grub.extraPrepareConfig}'
+    substituteInPlace extraPrepareConfig.sh \
+      --replace '${pkgs.coreutils}' '${pkgs.buildPackages.coreutils}' \
+      --replace '@bootPath@' "$bootdir"
+    source extraPrepareConfig.sh
+
+    cat <<EOF > $grubdir/grub.cfg
+    set timeout=3
+    set default=0
+    set gfxpayload=auto
+
+    ${config.boot.loader.grub.extraEntries}
+    EOF
+
+    grub-script-check $grubdir/grub.cfg
+
+
     # Make the ESP image twice as large as necessary
-    imageBytes=$(du --summarize --block-size=4096 --total $bootdir | tail -1 | awk '{ print int($1 * 8192) }')
+    imageBytes=$(du --summarize --block-size=4096 --total espRoot | tail -1 | awk '{ print int($1 * 8192) }')
 
     truncate --size=$imageBytes $img
     mkfs.vfat -n EFIBOOT --invariant $img
-    mcopy -sv -i $img EFI ::
+    mcopy -sv -i $img espRoot/* ::
     fsck.vfat -nv $img
 
     zstd --verbose --no-progress ./$img -o $out
diff --git a/nixos-modules/lib/make-ext2-fs.nix b/nixos-modules/lib/make-ext2-fs.nix
index 98d2103..013f14d 100644
--- a/nixos-modules/lib/make-ext2-fs.nix
+++ b/nixos-modules/lib/make-ext2-fs.nix
@@ -1,8 +1,6 @@
 { config, lib, pkgs, extraInputs ? [ ], contents }:
 
 let
-  grub' = pkgs.buildPackages.grub2_efi;
-
   copyEris = lib.strings.concatMapStrings ({ source, target }: ''
     cp -a --reflink=auto "${source}" "./rootImage/${target}"
   '') contents;
@@ -12,7 +10,6 @@ in pkgs.stdenv.mkDerivation {
 
   nativeBuildInputs = with pkgs.buildPackages; [
     e2fsprogs.bin
-    grub'
     libfaketime
     perl
     fakeroot
@@ -23,23 +20,7 @@ in pkgs.stdenv.mkDerivation {
     img=temp.raw
 
     # Create nix/store before copying path
-    mkdir -p ./rootImage/boot/grub ./rootImage/nix/store
-
-    cat > extraPrepareConfig.sh <<< '${config.boot.loader.grub.extraPrepareConfig}'
-    substituteInPlace extraPrepareConfig.sh \
-      --replace '${pkgs.coreutils}' '${pkgs.buildPackages.coreutils}' \
-      --replace '@bootPath@' './rootImage/boot'
-    source extraPrepareConfig.sh
-
-    cat <<EOF > ./rootImage/boot/grub/grub.cfg
-    set timeout=3
-    set default=0
-    set gfxpayload=auto
-
-    ${config.boot.loader.grub.extraEntries}
-    EOF
-
-    grub-script-check ./rootImage/boot/grub/grub.cfg
+    mkdir -p ./rootImage/nix/store
 
     (
       GLOBIGNORE=".:.."
@@ -65,7 +46,8 @@ in pkgs.stdenv.mkDerivation {
     faketime -f "1970-01-01 00:00:01" fakeroot mkfs.ext2 -L NIXOS_GENODE -U ${config.genode.boot.storeFsUuid} -d ./rootImage $img
 
     export EXT2FS_NO_MTAB_OK=yes
-    # I have ended up with corrupted images sometimes, I suspect that happens when the build machine's disk gets full during the build.
+    # I have ended up with corrupted images sometimes, I suspect that
+    # happens when the build machine's disk gets full during the build.
     if ! fsck.ext2 -n -f $img; then
       echo "--- Fsck failed for EXT2 image of $bytes bytes (numInodes=$numInodes, numDataBlocks=$numDataBlocks) ---"
       cat errorlog