Subject: Re: Section attributes from ld
From: [email-masked] (Jon Thackray)

16 Jul 1997 07:47:59 -0700
Approved: [email-masked]
Distribution: cygnus
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References: <[email-masked]>
	<[email-masked]>
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[email-masked] writes:
 > >How does ld determine which attributes sections are to have? By
 > >attributes, I mean things like:-
 > 
 > >Contains code, contains initialised data, should be laoded with
 > >execute permission, should be loaded with read permission, should be
 > >loaded with write permission etc.
 > 
 > The attributes are based on the attributes of the input sections which
 > are mapped into the output sections.  Take a look at
 > gas/config/obj-coff.c to see how to use the .section directive in an
 > assembler file.

As far as I can see, this allows me no control over the flags I'm
talking about. The ones I mean are documented in MSDN as:-

IMAGE_SCN_MEM_DISCARDABLE	0x02000000
IMAGE_SCN_MEM_NOT_CACHED	0x04000000
IMAGE_SCN_MEM_NOT_PAGED		0x08000000
IMAGE_SCN_MEM_SHARED		0x10000000
IMAGE_SCN_MEM_EXECUTE		0x20000000
IMAGE_SCN_MEM_READ		0x40000000
IMAGE_SCN_MEM_WRITE		0x80000000

It would appear that as automatcially puts MEM_READ and MEM_EXECUTE on
the .text section, MEM_READ and MEM_WRITE on the .data section and the
same on the .bss section. For sections it doesn't know about (eg I
have one called .dyfix), it outs none of these. However, my compiler,
when generating these sections, does add attributes such as MEM_READ
and MEM_WRITE, but then ld appears to throw them away (at least binary
editing the resulting executable or looking at it with any of the
tools available shows them to have gone away).

On a separate point, is a three stage link required (al la relocatable
dll) to produce relocatable .exe files?
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