On Tue, 2003-04-08 at 15:41, Shesha@asu.edu wrote:
> I am running 2.4.18 kernel for ARM. I have one of the boot parameters
> "profile=2". The size of the /proc/profile file is shown as 16MB. But when I
> execute "readprofile" the output is ...
> 0 total nan
>
> If I cat the file it just give me a ".". Can anyone suggest what i am doing
> wrong?
[ I swear I was just talking about this problem with someone else... ]
1. /proc/profile is a binary file. cat won't show you anything
meaningful.
2. the 0 output by readprofile is a problem with the automatic
byte-order detection heuristic built into the code. Try invoking
readprofile with the "-n" option, and see if your problem goes away.
FYI: For those that might also run into this, the essence of the problem
is this piece of code in readprofile.c (fragmented for clarity):
"optNative" is 0.
"buf" is an unsigned int *.
if (!optNative) {
int entries = len/sizeof(*buf);
int big = 0,small = 0,i;
unsigned *p;
for (p = buf+1; p < buf+entries; p++)
if (*p) {
if (*p >= 1 << (sizeof(*buf)/2)) big++;
else small++;
}
if (big > small) {
fprintf(stderr,"Assuming reversed byte order. "
"Use -n to force native byte order.\n");
<snipped>
.
.
.
}
}
Based on my read of the code, "big" will be incremented if *p >= 4,
otherwise "small" will be incremented. I can't see how this would ever
detect the byte order...
Werner proposed this as a solution, but it could still fail to correctly
detect the byteorder (although with much less frequency):
--- util-linux-2.11z/sys-utils/readprofile.c.orig Tue Apr 8 15:23:05 2003
+++ util-linux-2.11z/sys-utils/readprofile.c Tue Apr 8 15:29:29 2003
@@ -33,6 +33,8 @@
* - make maplineno do something
* 2002-11-28 Mads Martin Joergensen +
* - also try /boot/System.map-`uname -r`
+ * 2003-04-08 Werner Almesberger <wa@almesberger.net>
+ * - fixed off-by eight error in byte order detection
*/
#include <errno.h>
@@ -249,7 +251,7 @@ main(int argc, char **argv) {
for (p = buf+1; p < buf+entries; p++)
if (*p) {
- if (*p >= 1 << (sizeof(*buf)/2)) big++;
+ if (*p >= 1 << (sizeof(*buf)*4)) big++;
else small++;
}
if (big > small) {
