Inclusion of Custom NOLOAD Section in pei-x86-64 Output Binary

[Jan Beulich]

On 27.05.2025 11:30, Niteesh G. S. wrote:
> GNU binutils version 2.43.1
> Target Format: pei-x86-64
> 
> I'm encountering an issue with the GNU linker when defining a custom
> uninitialized data section in my linker script. Specifically, I have the
> following section defined:
> 
> .boot.bss (NOLOAD) : {
>   *(.boot.bss)
> }
> 
> My expectation is that this section, marked with the NOLOAD attribute,
> would not be included in the loadable segments of the output binary.
> However, upon inspecting the generated binary, I observe that .boot.bss is
> being included in the loadable segments, contrary to the intended
> behavior.
> 
> objdump -h  kernel.pe
> ------------------------------------------------------------------------------------------
> kernel/kernel.pe:     file format pei-x86-64
> 
> Sections:
> Idx Name          Size      VMA               LMA               File off
>  Algn
>   0 .boot.text    00000048  0000000000100000  0000000000100000  00000400
>  2**2
>                   CONTENTS, ALLOC, LOAD, READONLY, CODE
>   1 .boot.bss     00002000  0000000000101000  0000000000101000  00000600
>  2**2
>                   CONTENTS, ALLOC, LOAD, DATA
> -------------------------------------------------------------------------------------------
> 
> Is this the intended behaviour? How can I create a custom BSS section in
> non-elf targets?

About three years ago I had to look into this. My conclusion was that NOLOAD
is simply ignored for PE/COFF. See e.g. the comment resulting from that
analysis in
https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=dedb0aa42c6d1ee31805dfc61630db2c41117330

Jan