And here is the info in boards.txt....
atmega328_1mhz_4800baud.name=Optiboot 5 for bare 328P, 1MHz internal clock, fast start, 1.8V BOD, 4800baud upload, c/o tim7 20130416
atmega328_1mhz_4800baud.upload.protocol=arduino
atmega328_1mhz_4800baud.upload.maximum_size=32256
atmega328_1mhz_4800baud.upload.speed=4800
atmega328_1mhz_4800baud.bootloader.tool=arduino:avrdude
atmega328_1mhz_4800baud.bootloader.low_fuses=0x42
atmega328_1mhz_4800baud.bootloader.high_fuses=0xde
atmega328_1mhz_4800baud.bootloader.extended_fuses=0xfe
atmega328_1mhz_4800baud.bootloader.path=atmega
atmega328_1mhz_4800baud.bootloader.file=atmega328_1b.hex
atmega328_1mhz_4800baud.bootloader.unlock_bits=0x3F
atmega328_1mhz_4800baud.bootloader.lock_bits=0x2F
atmega328_1mhz_4800baud.build.mcu=atmega328p
atmega328_1mhz_4800baud.build.f_cpu=1000000L
atmega328_1mhz_4800baud.build.core=arduino
atmega328_1mhz_4800baud.build.variant=standard
atmega328_1mhz_4800baud.upload.tool=arduino:avrdude```.