On Mon, Sep 20, 2010 at 11:57 AM, Mulyadi Santosa <[email protected] > wrote:
> Hi... > > On Mon, Sep 20, 2010 at 12:11, naveen yadav <[email protected]> wrote: > > Hi all, > > > > I am facing one issue when executing below progmra on ARM target. The > > same program work well on X86 host machine, > <some message deleted....> > > But when execute on Target(ARM): > > # ./a.out 0 w 20 > > /dev/mem opened. > > Memory mapped at address 0x40003000. > > Value at address 0x0 (0x40003000): 0xEA000006 > > Written 0x14; readback 0xEA000006 > > # > > The value does not change. any idea .... > > First thing first, have you checked the permission of /dev/mem? > this program has read/write permission on /dev/mem. Otherwise, open would have failed. > > -- > regards, > > Mulyadi Santosa > Freelance Linux trainer and consultant > > blog: the-hydra.blogspot.com > training: mulyaditraining.blogspot.com > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > > I guess this issue has something to do with '/dev/mem' being physical memory. The address may have different value when data is set and different data when value is read due to page swapping or copy-on-write. I am just taking wild guess here, please correct me if I am wrong. -Vinit
