# flashrom

## Theory

Flashrom is an open-source tool used for reading, writing, verifying, and erasing flash memory chips. It supports a wide range of chipsets and is primarily used for flashing BIOS, firmware, and embedded systems. Flashrom is essential for penetration testers and hardware hackers, as it enables low-level access to the firmware of devices, allowing for potential vulnerabilities to be identified and exploited.

#### Key Features

* Cross-Platform
  * Available on Linux, Windows, and macOS.
* Wide Chip Support
  * Compatible with various flash chips and devices.
* Read/Write Operations
  * Allows for easy backup and flashing of firmware.
* Verification
  * Ensures that the flashing process was successful by comparing the written data with the source.
* Live Flashing
  * Can be used to flash a system while it is running.

## Cheat Sheet

```bash
# Install Flashrom on Linux
sudo apt-get update
sudo apt-get install flashrom

# Install Flashrom on macOS (using Homebrew)
brew install flashrom

# Detect the flash chip on your device
sudo flashrom -p <programmer>

# Example with Bus Pirate
flashrom -p buspirate_spi:dev=/dev/ttyUSB0,spispeed=1M

# Read flash memory and save it to a file
sudo flashrom -p <programmer> -r backup.bin

# Write a new firmware image to the flash chip
sudo flashrom -p <programmer> -w firmware.bin
```

### Installation

To install Flashrom on different platforms, you can follow these commands:

{% tabs %}
{% tab title="Linux" %}

```bash
sudo apt-get update
sudo apt-get install flashrom
```

{% endtab %}

{% tab title="OSX" %}
Here are the instructions for macOS using Homebrew

```bash
brew install flashrom
```

{% endtab %}

{% tab title="Windows" %}
**Installation Steps**

1. **Download Flashrom**:
   * Visit the [Flashrom Releases page on GitHub](https://github.com/flashrom/flashrom/releases) and download the latest `.zip` file for Windows.
2. **Extract the Zip File**:
   * After downloading, extract the contents of the `.zip` file to a directory of your choice.
3. **Set Up Environment**:
   * Open Command Prompt and navigate to the directory where you extracted Flashrom.
   * You may need to add the directory to your system's `PATH` environment variable for easier access.

**Example Commands**

If you want to use it directly without adding it to your PATH, you can navigate to the directory where Flashrom is located. For example, if you extracted it to `C:\flashrom`, you would use:

```bash
cd C:\flashrom
```

Then run Flashrom with the following command:

```bash
flashrom -p internal
```

{% endtab %}
{% endtabs %}

## Usage

#### Detecting the Chip

To detect the flash chip on a device, use:

```bash
sudo flashrom -p <programmer>
```

Replace `<programmer>` with the appropriate programmer (e.g., `linux_spi`, `internal`, etc.).

Example Bus Pirate:

```bash
flashrom -p buspirate_spi:dev=/dev/ttyUSB0,spispeed=1M
```

#### Reading the Flash

To read the flash memory and save it to a file:

```bash
sudo flashrom -p <programmer> -r backup.bin
```

#### Writing to the Flash

To write a new firmware image to the flash:

```bash
sudo flashrom -p <programmer> -w firmware.bin
```

## Expected Output

When the command executes successfully, you might see output similar to the following:

```vbnet
Flashrom v1.2.3-r1234 on Linux 5.4.0-74-generic (x86_64), built with libpci 3.6.4, gcc 9.3.0, little endian
   
Calibrating delay loop... OK.
Detected chipset: Intel H61
Found chip "W25Q64.V" (8192 KB, SPI) at physical address 0x00000000.
Reading flash... done.
Size: 8192 KB
Saved to backup.bin
```

### Important Notes

* Always ensure you have a valid backup of the current firmware before attempting to flash a new image.
* Incorrectly flashing firmware can lead to bricking the device, making it inoperable.
* Consult the Flashrom documentation for more detailed information and supported hardware.

## Resources

* [Flashrom website](https://www.flashrom.org/)
* [Flashrom Git repository](https://github.com/flashrom/flashrom)