Installing an operating system on a Raspberry Pi Compute Module is a fairly simple job. The problem shows up when you have to repeat it dozens or hundreds of times during a product’s manufacturing run. Spanish engineering firm blackdevice hit that exact bottleneck and built FlashRock, a hardware-and-software platform that can prepare up to seven Compute Modules in a single batch, compatible with Raspberry Pi CM4, CM5, and Radxa Compute Module 3.
FlashRock in 20 seconds
- FlashRock has seven slots for flashing Compute Modules in a single run.
- It’s compatible with Raspberry Pi CM4, Raspberry Pi CM5, and Radxa Compute Module 3.
- The software automatically detects the installed modules and lets you pick the OS image.
- Modules are flashed in pairs until the whole batch is done.
- blackdevice uses the tool in its own development, testing, and production workflows.
FlashRock started out as an internal tool. Many of the products blackdevice develops run custom operating systems, and each unit needs to be prepared before it goes into the finished product.
Doing that job module by module worked fine while volumes were low. As the number of units grew, flashing them one at a time started eating up too much time and turned into a repetitive chore inside the production process.
The company’s answer was to design its own system for working with several modules at once.
Seven Modules Connected, One Flashing Run
FlashRock’s hardware has seven dedicated slots for Compute Modules, connected through their respective Hirose connectors.
The platform currently supports three module families: Raspberry Pi Compute Module 4 (CM4), Raspberry Pi Compute Module 5 (CM5), and Radxa Compute Module 3 (CM3).
Once the modules are seated on the board, the operator connects power and USB. From that point, the software built for FlashRock takes over.
The app detects which modules are present and in which slots. The user can then choose which ones to prepare and select the OS image to write.
FlashRock then manages the flashing sequence itself.
According to blackdevice, modules are processed in pairs. Once a pair finishes, the system moves on to the next devices until every selected slot has been handled.
That detail means the seven units aren’t necessarily written at exactly the same time. The platform manages the batch and automatically works through it without the operator having to manually kick off the process for each Compute Module.
LED indicators on the board itself let you check status at a glance. When a module finishes flashing successfully, its indicator turns green.
The software also tracks the overall status of the batch and confirms once every module is ready.
The difference from doing it one unit at a time mostly comes down to the operator’s workload. Instead of connecting a module, flashing it, removing it, and starting over, they can load up several units and let FlashRock manage the sequence.
From Prototype to Production Line
Compute Modules are designed specifically to bring Raspberry Pi and other Arm-based platforms into custom products.
Unlike a standard Raspberry Pi board, a Compute Module packs the processor, memory, and other essential components into a form factor meant to plug into a carrier board designed specifically for each product.
That makes them common in industrial devices, embedded systems, digital signage, automation, robotics, and other equipment where using a full development board directly isn’t practical.
Once a product reaches production, a different problem shows up than the one you deal with during prototyping.
Preparing two or three modules by hand is perfectly manageable. Preparing 50, 100, or several hundred turns that same task into a meaningful part of the manufacturing process.
And it’s not just about doing it faster.
In production, you want every unit to receive the same image and follow a repeatable procedure. It also helps to have a clear signal about which devices finished successfully before moving on to assembly.
That’s the scenario blackdevice designed FlashRock for.
The tool centralizes image selection, identifies which slots are occupied, controls the flashing process, and provides visual feedback on the result.
It Can Also Re-Flash a Module
FlashRock isn’t limited to modules fresh off the line for production.
The board includes a mechanism to put an already-configured Compute Module back into the mode needed to rewrite its storage.
The operator can use the corresponding reset button, and FlashRock detects the device again, allowing a new OS image to be installed.
That capability means the tool can also be used during development and testing.
An engineering team might need to switch images repeatedly while testing different versions of its software. Later on, it can use the same system to prepare the units headed for production.
It also comes in handy when a batch of devices needs a complete refresh via a new image rather than an incremental update on top of the existing system.
The platform is designed to keep the same workflow working across different stages of a product’s life.
FlashRock Also Preps the Modules Used by Hive
One of FlashRock’s internal uses ties into another blackdevice project called Hive.
Hive uses Raspberry Pi Compute Modules inside nodes it calls beenodes. Each one runs its own operating system and needs to be prepared before joining the cluster.
FlashRock lets the team load the OS onto several of these modules in a single operation.
The case also illustrates something common at companies that design hardware: some of the tooling needed to manufacture a product ends up becoming an engineering project in its own right.
A company might develop a board or device, but it then needs test benches, systems for installing firmware, diagnostic tools, or mechanisms for automatically prepping units before shipping.
FlashRock falls into that last category.
It doesn’t necessarily end up as part of the product the end customer receives. Its role is in the process that happens beforehand — the one that lets that product get manufactured and prepared in a repeatable way.
Built for In-House Use, But Adaptable
blackdevice explains that FlashRock was initially designed around its own production needs, though it believes the same approach could be adapted to other projects built on Compute Modules.
The company has documented both the hardware and the software and offers additional information on possible configurations.
Current compatibility with CM4, CM5, and Radxa CM3 covers several platforms, but adapting it to other modules would require looking at each hardware’s connections, boot process, and specific flashing mechanisms.
FlashRock also isn’t trying to change how each Compute Module’s installation process works internally. Its contribution is grouping and controlling several units from a single tool.
That distinction matters.
In development environments, plenty of tasks that seem trivial can turn into production problems simply by being multiplied. Flashing one image barely requires any attention. Doing the exact same thing hundreds of times demands thinking about automation, repeatability, and error control.
FlashRock is a physical example of that leap: a task that could be done by hand ends up turning into a dedicated platform once the number of devices starts to grow.
Frequently Asked Questions
What is FlashRock?
FlashRock is a hardware-and-software platform built by blackdevice to flash multiple Compute Modules in a single batch. It has seven slots and automatically manages the process of installing the images.
Which Compute Modules work with FlashRock?
Current published compatibility includes Raspberry Pi Compute Module 4, Raspberry Pi Compute Module 5, and Radxa Compute Module 3.
Does FlashRock flash seven Compute Modules at the same time?
The platform can manage up to seven modules within a single batch. According to blackdevice, flashing happens in pairs, and the system automatically moves on to the next modules as each pair finishes.
Can it be used to reinstall the operating system?
Yes. A previously configured module can be put back into flashing mode using FlashRock’s built-in procedure and then receive a new OS image.
