Would it be possible to run Bruce from SD card?

[jesshampshire]

The scenario I'm thinking of is a regular firmware installed on the flash memory, and launcher installed, an extra button on launcher that would load Bruce (not flash) from SD card in a similar way to a PC loading from a hard drive.

If this is sensible and viable, could you make it a feature request, please?

[bmorcelli]

I don't think it is possible.. due to the binary structure, memory handling and resources concurrences..

I know a way to, possibly, run .elf files (lets say compile a project in a special way and run it from the sd card) but it limits a lot the firmware development.. because Launcher would need to provide many library resources, increasing its size.. This method is similar to what flipper zero does.. and the firmwares must be done specifically for this purpose (can't be flashed directly)

[jesshampshire]

Thanks for the reply.

So basically a ventoy like solution would be far too clumsy and inefficient to be an option? This is what I expected to be likely

But an MSDOS style set up would be viable? (With Launcher being the equivalent of the BIOS and Bruce being the equivalent
of command.com).

This could not be the same as the firmware, but could presumably the same executable could be common for all launcher ESP32 SD platforms, and potentially provide far more options?

And the interface would be available for other systems to use, too?

[bmorcelli]

It is not possible..

The binary MUST be copied to the flash memory to work..

Running from the SD card would need the target firmware (Bruce for example) to be compiled with some specific flags, use the .elf file for that, and the user experience would be very poor because it would run at half of the speed..

So no, it is not possible...

One thing that can be done is flashing more firmware into the device.. like having a boot selector (to point which firmware to load) and 2 or more App partitions that have the firmware installed plus a SPIFFS partition (data partition needed by some firmware like Bruce)

It would not work on 4mb flash devices, because the flash selector would use like 1mb amd the other 3mb wouldn't be enough for other firmware

8mb is better, but can store up to 2 firmware...
16mb is way better, storing up to 4 firmware at a time

I can do it, but it takes time.. you would be able to have Marauder, Bruce and some other stuff packed into one device

[jesshampshire]

I did wonder if dual firmware would be an option, interesting to know that it would be.

But the scenario I was thinking was for Meshcore (or MeshTastic) where I don't expect there to be spare space, and I obviously expect it not to be as fast. But for occasional light use it would be a better experience than flashing Bruce, then flashing Meshcore back after.

But if there were space to have MeshCore alongside Bruce, (or even Bruce and MeshTastic) that would be amazing.