There might be Powerbook Linux boot floppy, though NetBSD might be a better choice. The CPU appears to be a 68LC040: <https://support.apple.com/en-us/112137>
A NetBSD install guide which seems to have worked for someone in 2012: <https://web.archive.org/web/20120602135739/http://www.macuni...>
(Site is now SEO scambait.)
NetBSD docs: <https://wiki.netbsd.org/ports/macppc/>