Hacky script to use an ESP32 as an emergency BIOS/UEFI recovery flasher

esp32_spirecovery.ino

// WARNING! 
// THIS SCRIPT IMMEDIATELY ERASES ANY CONNECTED SPI FLASH ROMS AFTER STARTUP!
// WARNING! 

// Wiring:
// ESP32 CS0 (GPIO 5) - Flash /CS (Pin 1)
// ESP32 MISO (GPIO 19) - Flash DO (Pin 2)
// ESP32 GPIO 2 - Flash /WP (Pin 3)
// ESP32 GND - Flash GND (Pin 4)
// ESP32 MOSI (GPIO 23) - Flash DI (Pin 5)
// ESP32 V_SPI_CLK (GPIO 35) - Flash CLK (Pin 6)
// ESP32 V_SPI_HD (GPIO 21) - Flash /HOLD (Pin 7)
// ESP32 3V3 - Flash VCC (Pin 8)

#include <Arduino.h>
#include <SPIMemory.h>

int8_t SPIPins[4] = {-1, -1, -1, 33};

SPIFlash flash;


bool getID() {
	uint32_t JEDEC = flash.getJEDECID();
	if (!JEDEC) {
		Serial.println("No comms. Check wiring. Is chip supported? If unable to fix, raise an issue on Github");
		return false;
	}
	else {
		Serial.print("JEDEC ID: 0x");
		Serial.println(JEDEC, HEX);
		Serial.print("Man ID: 0x");
		Serial.println(uint8_t(JEDEC >> 16), HEX);
		Serial.print("Memory ID: 0x");
		Serial.println(uint8_t(JEDEC >> 8), HEX);
		Serial.print("Capacity: ");
		Serial.println(flash.getCapacity());
		Serial.print("Max Pages: ");
		Serial.println(flash.getMaxPage());
	}
	return true;
}

uint8_t buffer[4099];

void setup() {

	Serial.begin(115200);
	while (!Serial) ; // Wait for Serial monitor to open

	delay(50); //Time to terminal get connected
	Serial.print(F("Initialising"));
	for (uint8_t i = 0; i < 10; ++i)
	{
		Serial.print(F("."));
	}
	Serial.println();
	
	if (flash.error()) {
		Serial.println(flash.error(VERBOSE));
	}

	// H_SPI_WP (write protect) pin
	pinMode(2, OUTPUT);
	digitalWrite(2, HIGH);

	// V_SPI_HD (hold) pin
	pinMode(21, OUTPUT);
	digitalWrite(21, HIGH);
	
	flash.begin();

	getID();
	flash.eraseChip();
	Serial.println("E");
	uint32_t address = 0;
		
	// 8 MiB, change this to your flash size
	while (address < (8 * 1024 * 1024))
	{
		Serial.println("W");

		for (uint32_t i = 0; i < 4096; i++)
		{
			while (!Serial.available());
			buffer[i] = Serial.read();
		}
		flash.writeByteArray(address, buffer, 4096);
		address += 4096;

	}
}

void loop() {
	Serial.println("done!");
	delay(1000);
}

looks promising, might test it out