Help me find "linker script" in source code

bot

I'm a total newb. I'm trying to learn about embedded C programming, to better understand how RRF works. Where can I find the linker script? What is its filename and location? I'm such a newb I have no idea about conventions like this.

oliof

I assume you already did read through https://github.com/Duet3D/RepRapFirmware/blob/dev/BuildInstructions.md and have a working build setup?

arhi

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A Former User

i was under the impression eclipse generate that on the fly behind the scenes?

arhi

@bot said in Help me find "linker script" in source code:

Where can I find the linker script? What is its filename and location?

not that simple for project as complex with so many targets

e.g. for duet2ethernet linker scripts are (flash.ld is what you want to look at):

https://github.com/Duet3D/CoreNG/tree/master/variants/duetNG/linker_scripts/gcc

arhi

@bearer said in Help me find "linker script" in source code:

i was under the impression eclipse generate that on the fly behind the scenes?

not really
there are are some "default" linker scripts that come with "chip support" and some tools can create the linker script using input (what cpu, do you have external sram etc etc) but usually you have to deal with it yourself (I must say I'm far from master wrt that but I dabble)

bot

@oliof said in Help me find "linker script" in source code:

I assume you already did read through https://github.com/Duet3D/RepRapFirmware/blob/dev/BuildInstructions.md and have a working build setup?

Lol. No. Not at that point yet. I'm just learning about everything first. Like, introductory courses in C and embedded C. In these courses they mentioned linker scripts. I then searched the codebase on GitHub for linker script, and found comments referencing it but alas found no "linker script."

At the moment, I'm just curious about what would be in there, and how the memory is mapped for the different boards. I'm getting the sense that these scripts are built at compile time automatically?

@arhi said in Help me find "linker script" in source code:

@bearer said in Help me find "linker script" in source code:

i was under the impression eclipse generate that on the fly behind the scenes?

not really
there are are some "default" linker scripts that come with "chip support" and some tools can create the linker script using input (what cpu, do you have external sram etc etc) but usually you have to deal with it yourself (I must say I'm far from master wrt that but I dabble)

@arhi said in Help me find "linker script" in source code:

@bot said in Help me find "linker script" in source code:

Where can I find the linker script? What is its filename and location?

not that simple for project as complex with so many targets

e.g. for duet2ethernet linker scripts are (flash.ld is what you want to look at):

https://github.com/Duet3D/CoreNG/tree/master/variants/duetNG/linker_scripts/gcc

Well, thank you!! I will check these out. [edit: these are exactly what I was looking for, thank you!]

I wish that GitHub repos were more noob-friendly, with a "description" in the directory/file tree structure, rather than just commit messages.

[edit: I get it now. I was looking in the RRF repo. That's an abstraction layer. I wanted to be looking at CoreNG, which is the... part that comes before the OS? Or the part that comes after the OS? Or whatever it's not RRF! ]

arhi

@bot said in Help me find "linker script" in source code:

I wanted to be looking at CoreNG, which is the... part that comes before the OS? Or the part that comes after the OS? Or whatever it's not RRF! ]

The structure of the whole RRF is not to my liking (nothing wrong with it, just not what I am used to. For example, smoothieware, while waaaaaaaaaaaaaay less powerful than RRF, has the structure that's something I'm used to) and that's the main reason I was delaying my move to RRF for many years... but I bit the bullet and I didn't regret it. I'm still not fully clear on the RRF structure myself. I can build the firmware and make small adjustments but that's it. Still more time needed till I fully grasp the structure.

It would be cool if a document explaining the RRF structure existed, but it's not a simple thing to write, even harder to maintain, if not done by the firmware developer. And takes a huge amount of time from the firmware developer so... and I guess we all prefer bugfixes and new features to documentation

IMHO the best way to understand embedded development and how RRF work is to make this documentation .. bug dc42 trough PP/Forum/email/phone to gather info and than articulate it into a wiki :). Starting point can be