gsf.txt

GSF Specifications version 0.02

GSF is a PSF format for the GBA. The header of the file should begin with 'PSF' with a version byte
of 0x22. Next comes the Reserved section size, Program Section Size, and the Program CRC.

The Reserved section is reserved for the possible future use of storing a save state. You may not
delete/disregard this section.  The format of how the save state is stored has yet to be defined,
as there hasn't been an instance where a save state is needed.

The program section contains a GBA rom, that has been patched to only play back music.  If the rip
quality is good, then no graphics or any other such things should be in the VRAM/OAM/Pallete Ram.
It is layed out in the program section as follows

Offset         Size    Description
0x0000000      4       GSF_Entry_Point
0x0000004      4       GSF_Offset
0x0000008      4       Size of Rom.
0x000000C      XX      The Rom data itself.

The valid GSF_Entry_Points are 0x2000000 (Multiboot region), and 0x8000000 (Rom region).
The The High byte of the Offset should match the high byte of Entry_Point.

The offset/size helps you to know how much rom space to allocate, but is also used for
minigsf/gsflibs.  Look at the official psf specs for lib loading order.  Multiple libs are
now supported.

Finally, Look at the official psf specs for info on how tags are stored.