What this Tool does
Append an existing same-type 16-byte mGBA RTC trailer to an explicitly selected raw EEPROM 512 B save, using a validated template and preserving the raw source exactly.
Verification boundary
Raw source must be exactly the selected EEPROM 512 B size. A separate same-type mGBA template must already contain the 16-byte RTC trailer. No RTC state is synthesized. Save-memory type is an explicit user assertion. Phase 72 does not auto-detect GBA cartridge save type, synthesize or alter RTC state, repair game checksums, or treat extension/size as game identity.
Output and rollback
mGBA save containing the exact raw source plus the template RTC trailer, raw-source rollback, and deterministic SHA-256-bound proof JSON. The original selected source is never modified in place.
Before you convert
Keep an independent backup, use the exact representation named by this Tool, and test the resulting copy in the intended emulator or utility before replacing any working save.