On Mar 12, 2007, at 10:15, Jim Perrin wrote: >> 3. After copying the config file an making one small >> change with "make xconfig", why are there so many >> differences in the config file? > > Are they actual changes, or is the diff now simply off by a few lines? I went back and started the process of building a kernel from scratch on a different system. This time I paid closer attention to what was going on. After the "rpmbuild -bp --target=`uname -m` kernel-2.6.spec" step, the ~/rpmbuild/BUILD/kernel-2.6.9/linux-2.6.9 directory contains among other things these two files: -rw-r--r-- 1 rpmbuild rpmbuild 50332 Mar 12 15:32 .config -rw-r--r-- 1 rpmbuild rpmbuild 61600 Mar 12 15:31 .config.old Notice the size difference of these two files. After copying the config file from the ~/rpmbuild/SOURCES directory, these two files now look like this: -rw-rw-r-- 1 rpmbuild rpmbuild 61600 Mar 12 15:42 .config -rw-r--r-- 1 rpmbuild rpmbuild 61600 Mar 12 15:35 .config.old And a diff confirms the the two files are now identical. However, after doing a "make xconfig", changing two settings in the Serial Port section and saving the config file, the directory looks like this: -rw-rw-r-- 1 rpmbuild rpmbuild 50322 Mar 12 15:44 .config -rw-rw-r-- 1 rpmbuild rpmbuild 61600 Mar 12 15:42 .config.old Finally, comparing the new .config file with the original .config file only shows the expected changes: # diff /tmp/saved_configs/.config .config 4c4 < # Mon Mar 12 15:32:01 2007 --- > # Mon Mar 12 15:44:32 2007 1501c1501 < CONFIG_SERIAL_8250_NR_UARTS=4 --- > CONFIG_SERIAL_8250_NR_UARTS=16 1503c1503 < # CONFIG_SERIAL_8250_MANY_PORTS is not set --- > CONFIG_SERIAL_8250_MANY_PORTS=y While I don't quite understand what is going on, it appears that xconfig is doing the right thing. I'm rebuilding the kernel again as I type this. BTW, there are lots of compiler warnings: is this normal/expected for a kernel build? Alfred