build_library: support uefi boot from iso

Author: Nick Owens

build_library/grub.cfg

@@ -1,5 +1,17 @@
 # Main GRUB config
 
+# figure out the root
+if [ "$grub_platform" = "efi" ]; then
+    if [ -e "($cmddevice)/isolinux/efi.img" ]; then
+	set isoboot="1"
+    fi 
+
+    # on efi, $cmddevice has the disk grub was invoked from.
+    set root="$cmddevice"
+else
+    search --fs-uuid @@ESP_FSID@@ --set root --hint "$root"
+fi
+
 # Set the prefix back to the correct value after we're done with memdisk
 set prefix=($root)/coreos/grub
 
@@ -57,23 +69,25 @@ if [ "$net_default_server" != "" ]; then
 fi
 
 # Search for the OEM partition, load additional configuration if found.
-if [ "$secure_boot" = "0" ]; then
+if [ "$secure_boot" = "0" -a -z "$isoboot" ]; then
    search --no-floppy --set oem --part-label OEM --hint "$root"
    if [ -n "$oem" -a -f "($oem)/grub.cfg" ]; then
        source "($oem)/grub.cfg"
    fi
 fi
 
 # Determine if this is a first boot.
-search --no-floppy --set first_boot \
-       --disk-uuid 00000000-0000-0000-0000-000000000001
-if [ -n "$first_boot" ]; then
-    # Note we explicitly request the disk-guid randomization, first_boot only triggers ignition.
-    set first_boot="coreos.first_boot=1 coreos.randomize_disk_guid=00000000-0000-0000-0000-000000000001"
-fi
-
-if [ -n "$oem_id" ]; then
-    set oem_id="coreos.oem.id=$oem_id"
+if [ -z "$isoboot" ]; then
+    search --no-floppy --set first_boot \
+           --disk-uuid 00000000-0000-0000-0000-000000000001
+    if [ -n "$first_boot" ]; then
+        # Note we explicitly request the disk-guid randomization, first_boot only triggers ignition.
+        set first_boot="coreos.first_boot=1 coreos.randomize_disk_guid=00000000-0000-0000-0000-000000000001"
+    fi
+    
+    if [ -n "$oem_id" ]; then
+        set oem_id="coreos.oem.id=$oem_id"
+    fi
 fi
 
 # If no specific console has been set by the OEM then select based on
@@ -107,19 +121,27 @@ fi
 # Assemble the options applicable to all the kernels below
 set linux_cmdline="rootflags=rw mount.usrflags=ro consoleblank=0 $linux_root $linux_console $first_boot $oem_id $linux_append"
 
-menuentry "CoreOS default" --id=coreos {
-    gptprio.next -d usr -u usr_uuid
-    if [ "$usr_uuid" = "7130c94a-213a-4e5a-8e26-6cce9662f132" ]; then
-       linux$suf /coreos/vmlinuz-a @@MOUNTUSR@@=PARTUUID=$usr_uuid $linux_cmdline
-    else
-       linux$suf /coreos/vmlinuz-b @@MOUNTUSR@@=PARTUUID=$usr_uuid $linux_cmdline
-    fi
-}
-
-menuentry "CoreOS USR-A" --id=coreos-a {
-   linux$suf /coreos/vmlinuz-a @@MOUNTUSR@@=PARTLABEL=USR-A $linux_cmdline
-}
+if [ -z "$isoboot" ]; then
+    menuentry "CoreOS default" --id=coreos {
+        gptprio.next -d usr -u usr_uuid
+        if [ "$usr_uuid" = "7130c94a-213a-4e5a-8e26-6cce9662f132" ]; then
+           linux$suf /coreos/vmlinuz-a @@MOUNTUSR@@=PARTUUID=$usr_uuid $linux_cmdline
+        else
+           linux$suf /coreos/vmlinuz-b @@MOUNTUSR@@=PARTUUID=$usr_uuid $linux_cmdline
+        fi
+    }
+    
+    menuentry "CoreOS USR-A" --id=coreos-a {
+       linux$suf /coreos/vmlinuz-a @@MOUNTUSR@@=PARTLABEL=USR-A $linux_cmdline
+    }
+    
+    menuentry "CoreOS USR-B" --id=coreos-b {
+       linux$suf /coreos/vmlinuz-b @@MOUNTUSR@@=PARTLABEL=USR-B $linux_cmdline
+    }
+else
+    menuentry "CoreOS default" --id=coreos {
+       linux$suf /coreos/vmlinuz coreos.autologin= $linux_console
+       initrd$suf /coreos/cpio.gz
+    }
+fi
 
-menuentry "CoreOS USR-B" --id=coreos-b {
-   linux$suf /coreos/vmlinuz-b @@MOUNTUSR@@=PARTLABEL=USR-B $linux_cmdline
-}

build_library/grub_install.sh

@@ -54,14 +54,14 @@ case "${FLAGS_target}" in
         CORE_NAME="core.img"
         ;;
     x86_64-efi)
-	CORE_MODULES+=( serial linuxefi efi_gop getenv smbios efinet verify http )
+	CORE_MODULES+=( serial linuxefi efi_gop getenv smbios efinet verify http iso9660 )
         CORE_NAME="core.efi"
         ;;
     x86_64-xen)
         CORE_NAME="core.elf"
         ;;
     arm64-efi)
-        CORE_MODULES+=( serial efi_gop getenv smbios efinet verify http )
+        CORE_MODULES+=( serial linux efi_gop getenv smbios efinet verify http iso9660 )
         CORE_NAME="core.efi"
         BOARD_GRUB=1
         ;;
@@ -134,19 +134,16 @@ for file in "${GRUB_SRC}"/*{.lst,.mod}; do
 done
 
 info "Generating ${GRUB_DIR}/load.cfg"
-# Include a small initial config in the core image to search for the ESP
-# by filesystem ID in case the platform doesn't provide the boot disk.
-# The existing $root value is given as a hint so it is searched first.
-ESP_FSID=$(sudo grub-probe -t fs_uuid -d "${LOOP_DEV}p1")
+# Include a small initial config to set prefix and dump variables.
 sudo_clobber "${ESP_DIR}/${GRUB_DIR}/load.cfg" <<EOF
-search.fs_uuid ${ESP_FSID} root \$root
 set prefix=(memdisk)
 set
 EOF
 
 # Generate a memdisk containing the appropriately generated grub.cfg. Doing
 # this because we need conflicting default behaviors between verity and
 # non-verity images.
+ESP_FSID=$(sudo grub-probe -t fs_uuid -d "${LOOP_DEV}p1")
 GRUB_TEMP_DIR=$(mktemp -d)
 if [[ ! -f "${ESP_DIR}/coreos/grub/grub.cfg.tar" ]]; then
     info "Generating grub.cfg memdisk"
@@ -162,6 +159,9 @@ if [[ ! -f "${ESP_DIR}/coreos/grub/grub.cfg.tar" ]]; then
         sed 's/@@MOUNTUSR@@/mount.usr/' > "${GRUB_TEMP_DIR}/grub.cfg"
     fi
 
+    # fix up ESP UUID for PC boot. EFI boot will be able to provide the disk to grub.
+    sed --in-place --expression "s/@@ESP_FSID@@/${ESP_FSID}/" "${GRUB_TEMP_DIR}/grub.cfg"
+
     sudo tar cf "${ESP_DIR}/coreos/grub/grub.cfg.tar" \
 	 -C "${GRUB_TEMP_DIR}" "grub.cfg"
 fi

build_library/vm_image_util.sh

@@ -570,7 +570,7 @@ _write_cpio_disk() {
 }
 
 _write_iso_disk() {
-    local base_dir="${VM_TMP_ROOT}/usr"
+    local base_dir="${VM_TMP_ROOT}"
     local iso_target="${VM_TMP_DIR}/rootiso"
     local dst_dir=$(_dst_dir)
     local vmlinuz_name="$(_dst_name ".vmlinuz")"
@@ -579,7 +579,7 @@ _write_iso_disk() {
     pushd "${iso_target}" >/dev/null
     mkdir isolinux syslinux coreos
     _write_cpio_common "$1" "${iso_target}/coreos/cpio.gz"
-    cp "${base_dir}"/boot/vmlinuz "${iso_target}/coreos/vmlinuz"
+    cp "${base_dir}/boot/coreos/vmlinuz-a" "${iso_target}/coreos/vmlinuz"
     cp -R /usr/share/syslinux/* isolinux/
     cat<<EOF > isolinux/isolinux.cfg
 INCLUDE /syslinux/syslinux.cfg
@@ -594,8 +594,42 @@ label coreos
   kernel /coreos/vmlinuz
   append initrd=/coreos/cpio.gz coreos.autologin
 EOF
-    mkisofs -v -l -r -J -o $2 -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table .
-    isohybrid $2
+
+    # create fat image of grub for EFI
+    mformat -i isolinux/efi.img -C -v EFI -f 2880
+    mmd -i isolinux/efi.img EFI
+    mmd -i isolinux/efi.img EFI/BOOT
+
+    mcopy -i isolinux/efi.img -o "${base_dir}"/boot/EFI/boot/* "::EFI/BOOT/"
+
+    # syslinux won't work on arm64, and there is no point in isohybrid
+    # for arm64/uefi.
+    case $BOARD in
+        amd64-usr)
+            mkisofs -v -l -r -J -o $2 \
+                -eltorito-boot isolinux/isolinux.bin \
+                -eltorito-catalog isolinux/boot.cat \
+                -no-emul-boot \
+                -boot-load-size 4 \
+                -boot-info-table \
+                -eltorito-alt-boot \
+                -eltorito-platform efi \
+                -eltorito-boot isolinux/efi.img \
+                -no-emul-boot \
+                .
+
+            isohybrid --uefi $2
+        ;;
+        arm64-usr)
+            mkisofs -v -l -r -J -o $2 \
+                -eltorito-platform efi \
+                -eltorito-boot isolinux/efi.img \
+                -boot-info-table \
+                -no-emul-boot \
+                .
+        ;;
+    esac
+
     popd >/dev/null
 }