[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug ld/5785] New: Spurious "section xxx overlaps section yyy"

From: Nick Clifton
Subject: Re: [Bug ld/5785] New: Spurious "section xxx overlaps section yyy"
Date: Fri, 22 Feb 2008 11:29:16 +0000
User-agent: Thunderbird (X11/20071129)

Hi Sergei,

LD version 2.18.x produces bogus "section .xxx overlaps section .bss", while LD
version 2.16.1 works just fine.

Well the 2.18 linker is behaving as documented. Specifically in the bit on the "Output Section LMA" in the manual:

  If neither AT nor AT> is specified for an allocatable section,
  the linker will set the LMA such that the difference between
  VMA and LMA for the section is the same as the preceding output
  section in the same region.

Since the .bss section does not have an AT or an AT> directive its LMA is set to 0x110, so that difference between its VMA (0x4110), as set by the "> RAM" directive, and its LMA is 0x4000, ie the same as the difference between the VMA and the LMA of the .data section. (Try running the linker with the --no-check-sections option and then looking at the section headers to see this).

This is a change in the linker's behaviour that was made for the 2.18 release. There is even a mention of it in the NEWS file.

It does suggest a workaround for the problem: Change the "> RAM" in the description of the .bss section to "AT> RAM". ie:

   .bss : {
     . += 0x120;
   } AT> RAM

According to the manual this will set both the LMA and the VMA for the section, and you will end up with the same behaviour as the 2.16 linker. (This change is backwards compatible, i.e. it will work with the 2.16 linker as well). Unfortunately there is a bug in the current linker sources such that the "AT> [region-name]" syntax is ignored unless there is also an "> [region-name-2]" specified for the section, and the two regions are different. I can see no good reason for this, and the behaviour certainly isn't documented, so I am planning to check in the uploaded patch to remove this restriction unless my regression testing shows up a problem.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]