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Not really. I guess it should be somewhere in the gcc documentation.

But the format isn't so difficult to understand. The linker script is automatically generated, and in the IDE you can find it in your syslib -> Debug -> system_description -> generated.x

You can move it elsewhere, define it as a custom linker script in the system library properties, and modify it to suit your needs.

But be careful, any changes to the memory mapping in your SOPC system will not be automatically transferred to the linker script any more, you would have to change it manually.