From how I view linker scripts:
U can use a linker script to create file layout. If you want a flat binary file... u dont want a file layout. So linkerscript is really useless for a flat binary blob. Even if you make it with multiple files. It'd be just the same as saying: cat blob1 blob2 blob2 > finalyblob.
If you'd say have multiple blobs, and use linker directives to align them, the position dependent code within the assembled files will be wrong, unless you specifically define that using for example ORG directive in NASM.
If you use the ORG directive in NASM, u will need to keep that synchronized with the linker script in order for all the labels etc. to keep the right offsets calculated.
So essentially.. this linker script might even add complexity and issues when working with multiple binary blobs. u can't align them or use nice linker features....
If you use more structured files, which allow for example for relocation... then ur already using ELF or PE and can simple produce those files. They can be more masterfuly linked with nice features, and linker scripts are then essential.
You can add your binary blob in the right location in the output file of a linking run, using a linker script.
This is useful to add data into your files but for an MBR it's not particularly useful. People do it, but it adds no benefit over just sticking it on the front if your disk using 'dd' for example.
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That being my views, I am wondering what you see the benefit here? Are there some linker features i am unaware of that are particularly useful here? (I really know only alignment stuff in there... and include blobs or put stuff into /discard/ and some basic define sections/segments etc.). I am not familiar with perhaps more advanced linking features.