Confusion about value stored in linker script

Rick Mann rmann@latencyzero.com
Thu Nov 1 19:02:00 GMT 2007


I do a lot of this kind of thing:

	. = 0x80008000
	.text :
	{
		obj/start.o(.text);
		src/Interrupts.o(.text);
		
		. = ALIGN(4);
		gVectorsStart = .;
		KEEP (obj/vectors.o(.text));
		gVectorsEnd = .;
		
		. = ALIGN(4);
		*(.text);
	}


I expect gVectorsStart and gVectorsEnd to contain the value of the  
address at each point. In C, I refer to them like this:

typedef unsigned long UInt32;

extern UInt32*	gVectorsStart;
extern UInt32*	gVectorsEnd;



However, when I look at the values in those variables from the C code,  
it seems like the value contained is the value at that point in the  
link. In other words, the first few bytes of vectors.o are 0xe59ff018,  
and that's what I see as the value of the gVectorsStart. I *expected*  
to see that for *gVectorsStart (the pointed-to data). According to the  
map file:

                 0x8000807c                gVectorsStart = .
  obj/vectors.o(.text)
  .text          0x8000807c       0x3c obj/vectors.o
                 0x800080b8                gVectorsEnd = .


Summarizing, the C code thinks:

Vectors start address: 0xE59FF018
Vectors start &addres: 0x8000807C
Vectors first word:    0x8000807C

help! Thanks!

-- 
Rick



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