To install Linux on a SPARC based computer, should be strightforward if you follow the informations provided by your distribution.
To boot from a floppy drive you have to have an install image on a floppy disk and to issue the
boot floppy from the OpenBoot.
If your computer does not have a CDROM or a floppy drive, you can always try to perform a network installation using
NFS as explained by this French document: http://www.linux-france.org/article/materiel/sparc-install/Sparc-netinstall.html . Basicaly, you have to set up an
NFS server and to boot your computer using the
boot net vmlinux nfsroot=192.168.52.12:/tmp in order to access the image that is exported by the
192.168.52.12 computer on the
/tmp directory. Another source of information, this one is written in English, is this FAQ from the UltraLinux website ( http://www.ultralinux.org/faq.html#q_5_9 )