I am using nRF51 (PCA10028) DK and nRF51 SDK v9.0.0 for Development. I want to merge all three DFU(BLE + SERIAL + ANT). i have merge BLE and SERIAL DFU code. For this i have make changes in dfu_transport_ble.c, dfu_transport_serial.c, bootloader.c and dfu_types.h files. BLE DFU using nrf toolbox App is working ok, but when I perform Serial DFU Using nrfgo studio it shows error like "target is not in DFU mode. If using the SDK examples, press Button 4 and RESET and release both to enter DFU mode." i have checked that target is already in DFU Mode.
Target setting is,
Start Size
IROM1: 0x30000 0xFC00
IRAM1: 0x20002C00 0x5380
IRAM2: 0x20007F80 0x80