How Can I Have A Page With All Products Under All Category, Not Only One Root Category

How can I have a page with all products under all categories, not only one root category?

I know that is existing page for displaying all products under one category, how about a page for displaying all product under all categories which would be root of root categories,

Please use

with pagination:

index.php?dispatch=products.search&search_performed=Y

without pagination:

index.php?dispatch=products.search&search_performed=Y&items_per_page=9999

Please use

with pagination:

index.php?dispatch=products.search&search_performed=Y

without pagination:

index.php?dispatch=products.search&search_performed=Y&items_per_page=9999

Thank you so much, this could be a solution.