How to change the wordpress default logo from the Admin?

Question

I want to create a custom logo so I need change the default logo of the wordpress logo.

Answer 1

I did few arrangement:
- support the fullscreen mode
- use the favicon of the site so it is automatically customized for multisites, and you can put some default image if there is no favicon)
I put "width: 12px" to have a square shape for the favicon cover background
If it can help someone here is the code :

function my_custom_admin_logo() {
    echo '
        
    ';
}
//hook into the administrative header output
add_action('wp_before_admin_bar_render', 'my_custom_admin_logo');