[embedded] Create program without flash

Embedded
1

Hi,
I'm new to the Rust world and trying to recreate things which I had done in C/C++ world in Rust. One of my projects is using the Raspberry Pico without a flash. In the Pico SDK there is this no_flash feature, which basically just uses a different linkerscript. I try to do a similar thing in Rust. But as soon as I remove the flash from my memory.x file I get:

memory region not defined: FLASH

If I leave the memory region but insert the program into RAM I get:

ERROR(cortex-m-rt): The .text section must be placed inside the FLASH memory.
Set _stext to an address smaller than 'ORIGIN(FLASH) + LENGTH(FLASH)'

Is this something which is just not supported, or am I thinking to too much in the way of GNU linker?

Thanks for your help.

2

I've found a partly solution myself. It seems this is not possible with the cortex-m-rt generated linkerscript. I will have to create my own linkerscript from scratch to achieve what I want. This blog is helping me to find on how to do that Embedded Rust: customizing the Cortex-M exception vector table | Thomas

I have now a binary that links but does not start yet. But I guess that can be figured out. It just seems it was never considered to have no flash.