feat: secure boot noble

Author: mvallim

README.md

@@ -536,7 +536,7 @@ remove packages specified in `filesystem.manifest` that are *not* listed in `fil
 6. Generate md5sum.txt
 
    ```shell
-   /bin/bash -c "(find . -type f -print0 | xargs -0 md5sum | grep -v -e 'md5sum.txt' -e 'bios.img' -e 'efiboot.img' > md5sum.txt)"
+   /bin/bash -c "(find . -type f -print0 | xargs -0 md5sum | grep -v -e 'isolinux' > md5sum.txt)"
    ```
 
 ### Cleanup the chroot environment

scripts/chroot_build.sh

@@ -279,7 +279,7 @@ EOF
     cat /usr/lib/grub/i386-pc/cdboot.img isolinux/core.img > isolinux/bios.img
 
     # generate md5sum.txt
-    /bin/bash -c "(find . -type f -print0 | xargs -0 md5sum | grep -v -e 'md5sum.txt' -e 'bios.img' -e 'efiboot.img' > md5sum.txt)"
+    /bin/bash -c "(find . -type f -print0 | xargs -0 md5sum | grep -v -e 'isolinux' > md5sum.txt)"
 
     popd # return initial directory
 }

scripts/default_config.sh

@@ -7,7 +7,7 @@
 
 # The version of Ubuntu to generate.  Successfully tested LTS: bionic, focal, jammy, noble
 # See https://wiki.ubuntu.com/DevelopmentCodeNames for details
-export TARGET_UBUNTU_VERSION="noble"
+export TARGET_UBUNTU_VERSION="focal"
 
 # The Ubuntu Mirror URL. It's better to change for faster download.
 # More mirrors see: https://launchpad.net/ubuntu/+archivemirrors