A complete Seagate hard drive firmware contains APP, Cert, Cert table, ATA(7200.10 and .9 contains ATA 0 and ATA 1) and vendor modules and ROM module.
APP module: it’s necessary to load within level F command mode and it’s one codes module;
CERT module: it’s one selftest module;
CERT table: selftest process module;
ATA interface protocol module: after selftest, it’s necessary to load ATA;
Vendor info module: after selftest, it’s necessary to load ventor module.
Seagate hard drive can work on both normal mode and safe mode too like WD hard drive. Within safe mode, power on the hdd, the pcb is ready but the motor doesn’t spin up. When users want to read/write APP and ROM, it’s necessary to operate within safe mode. Anyway, functions within safe mode is limited.
Normal mode: most functions are run within normal mode and selftest needs to be run within normal mode too;
Safe mode: PCB mode and firmware is not working at all, when the APP module is damaged, the hdd enters level F command mode.