diff.diff-tree_--pretty=oneline_--root_initial

$ git diff-tree --pretty=oneline --root initial
444ac553ac7612cc88969031b02b3767fb8a353a Initial
:000000 040000 0000000000000000000000000000000000000000 da7a33fa77d8066d6698643940ce5860fe2d7fb3 A	dir
:000000 100644 0000000000000000000000000000000000000000 01e79c32a8c99c557f0757da7cb6d65b3414466d A	file0
:000000 100644 0000000000000000000000000000000000000000 01e79c32a8c99c557f0757da7cb6d65b3414466d A	file2
$