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Re: gcc: NOLOAD and .noinit

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On 19.3.22 17.27, pozz wrote:
> 
> You're right, .bss has only ALLOC attribute, while .text and .data have 
> LOAD attribute too.
> 
> It's strange because, as I wrote to David, my linker script doesn't use 
> NOLOAD for .bss sections.


Please look at the unlinked .o file of some module accessing the
.bss section. The LOAD attribute is missing there, also.

An example:

tauno@ubuntu:~/sandbox/lm3/app$ arm-none-eabi-objdump -h stest.o

stest.o:     file format elf32-littlearm

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
   0 .text         00000000  00000000  00000000  00000034  2**1
                   CONTENTS, ALLOC, LOAD, READONLY, CODE
   1 .data         00000000  00000000  00000000  00000034  2**0
                   CONTENTS, ALLOC, LOAD, DATA
   2 .bss          00001428  00000000  00000000  00000038  2**3
                   ALLOC
   3 .text.boot_thr 00000098  00000000  00000000  00000038  2**2
                   CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
   4 .text.net_thread 00000004  00000000  00000000  000000d0  2**1
                   CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
   5 .text.startup.main 0000008c  00000000  00000000  000000d4  2**2
                   CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
   6 .rodata       00000020  00000000  00000000  00000160  2**2
                   CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA
   7 .comment      0000005a  00000000  00000000  00000180  2**0
                   CONTENTS, READONLY
   8 .ARM.attributes 0000002d  00000000  00000000  000001da  2**0
                   CONTENTS, READONLY

It is the assembly phase of the compilation (GNU as) which knows
about the .bss section and leaves the LOAD bit off.

-- 

-TV

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Thread

gcc: NOLOAD and .noinit pozz <pozzugno@gmail.com> - 2022-03-19 08:02 +0100
  Re: gcc: NOLOAD and .noinit David Brown <david.brown@hesbynett.no> - 2022-03-19 11:33 +0100
    Re: gcc: NOLOAD and .noinit pozz <pozzugno@gmail.com> - 2022-03-19 16:20 +0100
      Re: gcc: NOLOAD and .noinit David Brown <david.brown@hesbynett.no> - 2022-03-19 16:49 +0100
  Re: gcc: NOLOAD and .noinit Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2022-03-19 12:46 +0100
    Re: gcc: NOLOAD and .noinit pozz <pozzugno@gmail.com> - 2022-03-19 16:27 +0100
      Re: gcc: NOLOAD and .noinit Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2022-03-19 18:57 +0200
  Re: gcc: NOLOAD and .noinit kegs@provalid.com (Kent Dickey) - 2022-03-21 04:43 +0000

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