Hi wimb!
I also get blinking cursor for a half minute when setup loads firadisk driver from virtual floppy. If cursor blinks "forever", I think you mistyped the firadisk parameters (write (99) ...).
"Why do you refer first to XP-1.vhd and then for FiraDisk Options to XP-4.vhd" - It was a mistype.
Please try this config exactly:
title Start - TXT-mode XP Setup
map --mem (md)0x800+4 (99)
map /setup.iso (0xff)
map --mem /firadisk.img (fd0)
map --mem /firadisk.img (fd1)
map /XP.vhd (hd0)
map --hook
write (99) [FiraDisk]\nStartOptions=cdrom,vmem=find:/setup.iso;disk,vmem=find:/XP.vhd,boot;\n\0
chainloader (0xff)
title Continue GUI-mode XP Setup
map --mem (md)0x800+4 (99)
map /setup.iso (0xff)
map --mem /firadisk.img (fd0)
map --mem /firadisk.img (fd1)
map /XP.vhd (hd0)
map --hook
write (99) [FiraDisk]\nStartOptions=cdrom,vmem=find:/setup.iso;disk,vmem=find:/XP.vhd,boot;\n\0
chainloader (hd0)+1
I created the blank vhd file with oracle virualbox, and have it with firadisk.img and setup.iso on the root of a partition.