Also, since Akira's port seems to be quite far along, you'd be better off using that as your base and just making a new sub.
"...The source [#3] by akira for, filewrite.c, movie_rec.c, capt_seq.c are still
based on the a2500 port...."
Only [#3] Boot.c is done the filewrite.c, movie_rec.c, capt_seq.c files are just direct copies of the a2500.
So, in terms of file size, Akira's port is less than 20% done.
H-H's version, in terms of file size, is about 90%++ done, BUT not yet de-bugged.
For #1 Ixus 265 and sx600. [paired]
For #2 Ixus 145, 150, 155 and Sx400. [as a set]