@Arjun, I think it’s time to step back and review. The P1 contains a P0 module which is the STM32F205 MCU and the Broadcom (Cypress now) wifi chip. The board also has an external SPI flash of 1MB in size. The STM32 MCU has 1MB of onboard flash, most of which is used by the Particle firmware AND a small amount for emulating EEPROM. The external SPI flash is commonly used with the
flash-eeprom library to simplify the use of the external flash.
Flash memory supports a limited number of erase cycles before it wears out. As such EEPROM emulation software uses extra flash memory in order to support “wear leveling” and extend the life of the flash.
Now, back to your question. On the P1, the 2047 bytes of EEPROM is emulated from onboard (not external) flash. The EEPROM emulation uses two 16KB pages of flash to emulate 2KB of EEPROM with wear leveling. Accessing the external SPI is not documented and a forum search may be necessary. This external flash is not accessible via DFU (that I know of).
Which flash memory are you wanting to use?