From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens To: Gabriel Paubert cc: linuxppc-dev@lists.linuxppc.org Subject: Re: Where does ppc define __start___ksymtab? In-reply-to: Your message of "Thu, 03 Aug 2000 14:01:44 +0200." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 03 Aug 2000 22:18:36 +1000 Message-ID: <31728.965305116@ocs3.ocs-net> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Thu, 3 Aug 2000 14:01:44 +0200 (METDST), Gabriel Paubert wrote: >On Thu, 3 Aug 2000, Keith Owens wrote: >> If we want anything in the kernel then we put it there, and say where >> we want it. Anything not explicitly listed is discarded. I just did >> this with ix86 and vmlinux shrank by 9K, mainly in .bss. It would not >> boot afterwards so obviously some part of that 9K is required but right >> now it works by some "magic" storing the unknown sections. I'm going >> to track down which sections are not being explicitly placed. > >I have trouble parsing this, since the bss by definition does not occupy >any space in vmlinux. It is wierd. Even though arch/i386/vmlinux.lds contains ".bss : { *(.bss) }", something extra is getting stored in .bss. The data has the same attributes as .bss, ALLOC only, alignment 2**5 but its section name is not ".bss". Adding .note : { *(.note) } .rest : { *(*) } to the end of an otherwise untouched arch/i386/vmlinux.lds changes vmlinux from this 14 .bss 0003bb8c c02a6c40 c02a6c40 001a7c40 2**5 ALLOC 15 .comment 000044a0 00000000 00000000 001a7c40 2**0 CONTENTS, READONLY 16 .note 00001680 c02e27cc c02e27cc 001ac0e0 2**0 CONTENTS, READONLY to this 14 .bss 00014240 c02a6c40 c02a6c40 001a7c40 2**5 ALLOC 15 .comment 000044a0 00000000 00000000 001a7c40 2**0 CONTENTS, READONLY 16 .note 00001680 c02bae80 c02bae80 001ac0e0 2**0 CONTENTS, READONLY 17 .rest 0002794c c02bae80 c02bae80 001a7c40 2**5 ALLOC Which is a lot more than 9K of unknown data. I was looking at the on disk size which contains the .note section, however removing that should only shrink by 4K so I do not understand why vmlinux shrank by 9K. The final step on i386 removes .note and .comment from the bootable kernel anyway. I'm trying to track down where the extra .bss like data is coming from. I will mail the list when I find something. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/