-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Wednesday 14 July 2004 12:48, amith wrote: > Muli Ben-Yehuda wrote: > >On Wed, Jul 14, 2004 at 03:50:06PM +0530, amith wrote: > >>mine.c :3: warning:'packed' attribute ignored. > > > >It's a single pointer. What exactly is there for the compiler to pack? > > > >Cheers, > >Muli > > hi there, > u r observations are right . > i was reading this FAQ on porting Linux applications to ARM. follows > from http://www.arm.com/support/faqdev/1228.html > --------------------------------------------------------------------------- >--------------------------------------------------------------------- Thus > if you wish to define a pointer to a word that can be at any > address (i.e. that can be at a non-natural alignment) then you must > specify this using the __packed qualifier when defining the pointer: > > __packed int *pi; // pointer to unaligned int > --------------------------------------------------------------------------- >--------------------------------------------------------------------- > > later i learnt that __packed is recognised by armcc compiler , i tried > using arm-linux-gcc , with __attribute__(packed)), assuming both do the > same. > Could someone point out the gcc equivalent of __pack , i feel it doesnt > make sense using __attribute__((packed)) on void **ptr. Hi there, I don't know if i'm correct but packed means that the variable whose attribute is being set to packed should be "packed" :) as close as possible ("should have the smallest possible alignment" - from Using GCC) to a preceding variable. Here's the example from the docs that might bring more clarity to the situation: struct foo { char a; int x[2] __attribute__ ((packed)); }; so the field x immediately follows a. Regards, Boris. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFA9RQdiBySr3Fn37QRAuxDAJ9kT0C/Ry0iS7TtXEaPA07UwlQkqwCcCMyd kRK3qrD3L4GmbnJTQ/sp+g4= =887u -----END PGP SIGNATURE----- -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
