Flash doesn't work for esp-12

[chaojijun52]

I'm quite new to esp8266 and have noticed that this repository hasn't been maintained for a while. But now I want to use https://github.com/martin-ger/esp_slip_router, which is based on esp-open-sdk. The current situation is that I've successfully made the sdk. blank.bin and esp_init_data_default.bin have been successfully generated. Also, I made the blinky example and got blinky-0x00000.bin and blinky-0x10000.bin generated. Then I got stuck at how to successfully flash the bins into my esp-12f nodeMCU.

I know that the flash size of esp-12f is 32Mbit, which should be 4MB. According the document https://www.espressif.com/sites/default/files/documentation/2a-esp8266-sdk_getting_started_guide_en.pdf, the addresses to flash bins should be as follows:
blank.bin: 0x3FB000 & 0x3FE000
esp_init_data_default.bin: 0x3FC000
blinky-0x00000.bin: 0x00000
blinky-0x10000.bin: 0x10000

In the tool ESP8266 DOWNLOAD TOOL V3.8.5, I set the bins and addresses as above, as well as the following settings. Then clicked the "START" button and waited for "FINISH". It showed the flash successful. But after I re-plug the nodeMCU or pushed the RST button, the onboard blue LED light blinked fast for once then became quiet.
CrystalFreq: 26M
SPI SPEED: 40MHz
SPI MODE: QIO
FLASH SIZE: 32Mbit
COM: COM3
BAUD: 115200

I'm able to flash the combined bins, the address is set to 0x0, provided by the producer. The onboard LED light can be successfully lit up.

Additionally, I've tried to have the simplest code as below, which only prints the SDK version, flashed again. Unfortunately, I got no luck.
#include "ets_sys.h"
#include "osapi.h"
#include "gpio.h"
#include "os_type.h"

void user_init() {
os_printf("SDK version: %s\n", system_get_sdk_version());
}

I tried the addresses from the official document, #279 and other posts online, but all failed. So can anyone help me with this?