AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

kconfig: allow specifying the seed for randconfig

Browse Source 
For reproducibility, it can be useful to be able to specify the
seed to use to seed the RNG.

Add a new KCONFIG_SEED environment variable which can be set to
the seed to use:
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config

It's very usefull for eg. debugging the kconfig parser.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
This commit is contained in:
Yann E. MORIN 2013-04-13 22:49:13 +02:00
parent 422c809f03
commit 0d8024c6eb
2 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Documentation/kbuild/kconfig.txt
View File

@ -89,6 +89,15 @@ These examples will disable most options (allnoconfig) but enable or
disable the options that are explicitly listed in the specified
mini-config files.
______________________________________________________________________
Environment variables for 'randconfig'
KCONFIG_SEED
--------------------------------------------------
You can set this to the integer value used to seed the RNG, if you want
to somehow debug the behaviour of the kconfig parser/frontends.
If not set, the current time will be used.
______________________________________________________________________
Environment variables for 'silentoldconfig'

12
scripts/kconfig/conf.c
View File

@ -13,6 +13,7 @@
#include <getopt.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <errno.h>
#include "lkc.h"
@ -514,14 +515,23 @@ int main(int ac, char **av)
{
struct timeval now;
unsigned int seed;
char *seed_env;
/*
* Use microseconds derived seed,
* compensate for systems where it may be zero
*/
gettimeofday(&now, NULL);
seed = (unsigned int)((now.tv_sec + 1) * (now.tv_usec + 1));
seed_env = getenv("KCONFIG_SEED");
if( seed_env && *seed_env ) {
char *endp;
int tmp = (int)strtol(seed_env, &endp, 10);
if (*endp == '\0') {
seed = tmp;
}
}
srand(seed);
break;
}