Add a 2G loop device for emergency swap

setup.sh

@@ -1300,6 +1300,10 @@ function get_disks_with_one_efipart () {
 
 function install_os_in_chroot () {
     #2.2
+    dd if='/dev/zero' of='/swapfile' bs='1M' count='2048'
+    losetup '/dev/loop9' '/swapfile'
+    mkswap '/dev/loop9'
+    swapon '/dev/loop9'
     ### Reinit keyring
     # As keyring is initialized at boot, and copied to the install dir with pacstrap, and ntp is running
     # Time changed after keyring initialization, it leads to malfunction
@@ -1346,6 +1350,9 @@ function install_os_in_chroot () {
         add_syslinux_pacman_hook
     fi
     add_zbm_pacman_hook
+    swapoff '/dev/loop9'
+    losetup -d '/dev/loop9'
+    rm '/swapfile'
 }
 
 function set_root_pw () {