github.com/mvdan/u-root-coreutils@v0.0.0-20230122170626-c2eef2898555/pkg/boot/fit/testdata/README.md (about)

     1  # How to create the test fit image
     2  
     3  * install u-boot tools
     4  ```shell
     5  apt-get install u-boot-tools
     6  ```
     7  
     8  * create dummy kernel and initramfs
     9  ```shell
    10  IMAGE_SIZE=100
    11  yes "k0" | tr -d '\n' | head -c $IMAGE_SIZE > $tmp_dir/dummy_kernel_0
    12  yes "k1" | tr -d '\n' | head -c $IMAGE_SIZE > $tmp_dir/dummy_kernel_1
    13  yes "i0" | tr -d '\n' | head -c $IMAGE_SIZE > $tmp_dir/dummy_initramfs_0.cpio
    14  ```
    15  
    16  * create signatures to embed
    17  ```shell
    18  key0=042FF30F752685F2
    19  key1=9ED18B2103E33767
    20  gpg --import ./key0 ./key1
    21  gpg --default-key $key0 --output $tmp_dir/key0_initram0_pgp.sig --detach-sig $tmp_dir/dummy_initramfs_0.cpio
    22  gpg --default-key $key1 --output $tmp_dir/key1_initram0_pgp.sig --detach-sig $tmp_dir/dummy_initramfs_0.cpio
    23  gpg --default-key $key0 --output $tmp_dir/key0_kernel0_pgp.sig --detach-sig $tmp_dir/dummy_kernel_0
    24  ```
    25  
    26  * optional clean up keyring
    27  ```shell
    28  gpg --delete-secret-key $key0 $key1
    29  gpg --delete-key $key0 $key1
    30  ```
    31  
    32  *  create itb file
    33  ```shell
    34  mkimage -f fitimage.its fitimage.itb
    35  ```