On 5.4.2011 21:17, Valdis.Kletnieks@xxxxxx wrote: > On Tue, 05 Apr 2011 17:10:34 +0200, Armin Schindler said: >> On Tue, 5 Apr 2011, Michal Marek wrote: >>> The kernel already prints its build timestamp during boot, no need to >>> repeat it in random drivers and produce different object files each >>> time. >> >> The module can be build separately from the kernel, therefore it can have >> an own build timestamp. > > If the same code is being built as an out-of-tree module, that's a possibly > good reason for a code version variable, but what does the build timestamp > actually tell you? If you already know foo_driver.c version 0.814 was buiilt > against 2.6.41-rc2, in what cases does it matter if the compile was on Tuesday > or Thursday - especially since an 'ls -l foo_driver.ko' will tell you? If it's > a matter of "the target .config changed on Wednesday", a build timestamp still > doesn't help over 'ls -l'. Exactly. Build timestamps are only a poor substitute for proper version tracking. If you want to be able to reproduce the build of a binary, you want it to embed some source revision, not the date when you built it. For the kernel, you can use KBUILD_BUILD_TIMESTAMP=<source timestamp>, for out-of-tree modules, you need to come up with something own. Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
