Linux 2.6.x Decreasing Kernel size, shorten boot time!

[mmarab]

Hi, I am pretty new to the Linux kernel, I have managed to build it and run it onto a blackfin, I would like to reduce the size of the kernel, by removing any unnecessary applications or features within it, to hopefully decrease the time in which the kernel takes to boot up.

Would I be correct in thinking, that I should use "make menuconfig", to remove any unnecessary features, therefore deceasing the size of the kernel and hopefully deceasing the boot up time? Any help would be great!

Thanks

Mmarab

[Zelmo]

You can reconfigure your kernel, but be aware that it won't save much time booting. It probably also won't be any smaller, since kernels are usually set to compile most drivers as modules. So the running kernel starts out just about as small as a kernel can be, and only gets as big as it really has to by loading modules when they're needed.

Still, if you want to do it, make sure you know your hardware well enough (manufacturer, chipset name, and model for most components), and follow the kernel rebuild guide, or better yet, find a guide that's written for your particular distro.

[mmarab]

Thank you for the replay, i was wondering if you had any other methodsthat could be used to do this.

Thanks
mmarab

[Zelmo]

To do what, exactly? Configure the kernel or shorten boot time?

[mmarab]

Hi,


Thanks for the help. I found using 'make menuconfig' that i could take parts of the kernel out which i did not need and make the compressed image smaller, which when the kernel booted, the uncompression time was shorter reducing the boot time.

I have also found that loading an uncompressed kernel from flash memory boots very fast, as the decompression part of the linux boot takes no time. Although the load time for the kernel is slightly longer as the uncompressed version of the kernel is about 9mbs and compressed it is 1.9mb.

I also found that the GZIP algorithm is rubbish, i changed the compression option of GZIP is the make file from 9(being the best compression) to 1(being the rubbished compression) i did this becuase i thought if the compressed image was not compressed very well then i could decompress it faster. BUT the compression of GZIP using option 1-9 does not make any difference.

Thanks for your time and help.