SRAM patching is easy to confuse with applying an ordinary game hack. A normal UPS or BPS changes the game relative to a dump. An SRAM or batteryless patch changes the save routine so a cart without a battery, or a cart with a different save chip, can keep the file. GBATEK is the reference I use for the commercial picture: GBA saves are SRAM, flash, or EEPROM, and the game code talks to that chip. Rewriting that code is a different patch than a translation.
Two public projects show the split. GBA-Save-Fix-Patcher describes a toolchain for save fixes. Its readme points at metroid-maniac's gba-auto-batteryless-patcher. I opened the first repository. The second is cited by that readme and I did not open it as its own page, so I treat the pair as one lead plus a quotation, not as two independent confirmations. I will not paste a procedure copied from a repo I did not read.
What I will say: do not expect the home button to perform this rewrite. Feed it a .ups and it applies a UPS. If a project ships the save fix as an IPS or UPS you can apply it like any other file, and the readme should say which base it hashed. SuperFW shows up in the same search cluster. I have not verified how SuperFW relates to these patches, so I am not describing it.
Related pages: the GBA console guide for ordinary hacks, the UPS format page, and the error index if a checksum fails. Save-type settings inside mGBA are an emulator concern after the file exists.
