MSP430F2350: Overlay sections with UNION statement in the linker script

Jason Liszewski67

Part Number: MSP430F2350

To reduce the ram usage I'm trying to use the UNION statement in the linker script to overlay the globals in remote_update.c with the globals used in the reset of the firmware. The following works, but I'm not happy with it. How can I tell the linker to overlay the globals from remote_update.c with ALL other globals, not just the ones from link.c?

	UNION:
	{
		.bss:p1:		: { link.obj(.bss) }
		.bss:p2:		: { remote_update.obj(.bss) }
	}		 > RAM
  	.bss        : {} > RAM                  /* Global & static vars              */

over 5 years ago

0 George Mock over 5 years ago

TI__Guru**** 232920 points

Please read the first part of the article Linker Command File Primer, especially to get an understanding of the term output section. A UNION is a collection of output sections which all begin at the same address. So I suggest you do something similar to ...

UNION
{
    .bss_remote          /* global & static vars for remote */
    { 
        remote_update.obj(.bss)
    }

    .bss                 /* all other global & static vars  */

} > RAM

Thanks and regards,

-George

0 Jason Liszewski67 over 5 years ago in reply to George Mock

Prodigy 30 points

Thanks George,

I had tried something similar but I was getting the syntax wrong. I did have to tweek your answer just a bit. Thanks again.


UNION:
{
	.bss_remote : { remote_update.obj(.bss) }	/* global & static vars for remote */
	.bss						                        /* all other globals & static vars */
}  > RAM

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MSP430F2350: Overlay sections with UNION statement in the linker script