Re: question about building a custom kernel
ill...@gmail.com writes: > You aren't going to gain much in speed or size savings, so > do take care to understand what you hope to gain. While I haven't done even an eyeball check recently, not too long ago the size savings for an aggressively pruned kernel could be quite noticable; there was also anecdotal support (waves hand) forfaster performance. Barring that? Every part of the kernel is something that can possbily go wrong, either by itself or by interacting with another part; if it isn't there, it can't break. Now the record on this really pretty awesome ... on the other hand, I can't argue with the person who doesn't want to roll those dice. And compile times of current generation hardware are pretty short. On an AMD Phenom II x4 940 (3 ghz) it's 5 minutes, maybe less. Robert Huff ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: question about building a custom kernel
On Sat, 19 Dec 2009 14:46:27 -0500 "ill...@gmail.com" wrote: > You aren't going to gain much in speed or size savings, so > do take care to understand what you hope to gain. If you > wish to shorten kernel compile times and reduce the size of > /boot, have a look at the MODULES_OVERRIDE and > WITHOUT_MODULES variables in /etc/make.conf. That > said, good luck, I haven't had any serious problems and I've > been using custom kernels since FreeBSD 4.1 or so. > While I agree in principle that compiling a custom kernel isn't usually worth it on modern machines, I recently gained a 65% disk space saving over GENERIC by bulding a custom kernel. Granted that was achieved because it's installed on a router with just 128MB RAM so I removed things like wifi and usb support, opted for "device mii" and added the PHY drivers I knew were used and added pf support, but it does show that substantial savings are still possible. Another reason for building a custom kernel is to add functionality that isn't available through modules, such as support for DTrace. -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: question about building a custom kernel
2009/12/19 Jamie Griffin : > Hi > > I have been reading the handbook to learn about building a custom > kernel, but just wanted to ask something about gathering information > about my hardware before I give it a go. > > The handbook suggests the command: > > # pciconf -lv > > ...which I like because it provides a clear list of components I can find > out about before I try to build the new kernel. > > On my system, this command does print out information for quite a few > components, I just wondered if this information is all I need to work > from or is it not an accurate or detailed enough representation of the > hardware I have in my computer. I'd really appreciate any advice on how > others go about this. > A couple of words of caution, based on the number of mails sent to this list complaining about "things not working": Always leave "device scbus" and "device da" in unless you're dead certain you'll never use a usb drive (& you'll also have to comment out "device umass" and maybe a couple of others to make it compile) among other things. "device miibus" should be left in too, again unless you really know for certain you don't need it. You may as well toss in "device drm" and the specific drm driver for your graphics card while you're going to the trouble. You aren't going to gain much in speed or size savings, so do take care to understand what you hope to gain. If you wish to shorten kernel compile times and reduce the size of /boot, have a look at the MODULES_OVERRIDE and WITHOUT_MODULES variables in /etc/make.conf. That said, good luck, I haven't had any serious problems and I've been using custom kernels since FreeBSD 4.1 or so. -- -- ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: question about building a custom kernel
On Sat, Dec 19, 2009 at 04:13:09PM +, Jamie Griffin wrote: > The handbook suggests the command: > > # pciconf -lv > > On my system, this command does print out information for quite a few > components, I just wondered if this information is all I need to work > from or is it not an accurate or detailed enough representation of the > hardware I have in my computer. I'd really appreciate any advice on how > others go about this. It should provide most of the information that you need. But it shows only for devices that are connected to the PCI bus! Devices connected to the USB bus will not show up here (except from the USB controllers). If you look at the first line for every device, the one with the @ in it, you can see if a driver has attached to that device in question. Devices whose name start with 'none' followed by a number followed by @ do not have a driver installed. Another thing you should look for is which modules are loaded, use the command 'kldstat' for that. Also have a look at the output of the 'dmesg' command. That will show you which devices are being detected and initialized. This will also show you what kind of CPU you have. Roland -- R.F.Smith http://www.xs4all.nl/~rsmith/ [plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated] pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725) pgpH4xyDqnSZv.pgp Description: PGP signature
Re: question about building a custom kernel
On Sat, Dec 19, 2009 at 10:41:14AM -0700, Tim Judd wrote: > Can I ask for more details from you why you're interested in building > a custom kernel? > --TJ Thanks for the information Tim. I don't have a specific need to build a custom kernel at the moment, I really just want to learn how to do it properly. I'm in my first year at University and we're learning about UNIX systems so i'm just experimenting really. Jamie pgpGrdHjWpfTZ.pgp Description: PGP signature
Re: question about building a custom kernel
On 12/19/09, Jamie Griffin wrote: > Hi > > I have been reading the handbook to learn about building a custom > kernel, but just wanted to ask something about gathering information > about my hardware before I give it a go. > > The handbook suggests the command: > > # pciconf -lv > > ...which I like because it provides a clear list of components I can find > out about before I try to build the new kernel. > > On my system, this command does print out information for quite a few > components, I just wondered if this information is all I need to work > from or is it not an accurate or detailed enough representation of the > hardware I have in my computer. I'd really appreciate any advice on how > others go about this. > > Jamie > Jamie, pciconf will list pci devices only (and their derivatives, like PCI-X and PCI-e). ISA devices (if any) are done differently, and also usb devices (usbdevs). Building a custom kernel most of the time involves the following decisions: embedding a firewall, so you cannot disable a firewall by unloading a module. Extending options, filesystem quotas for example. The modular kernel can add devices by modules, but can't really add options. Embedded solutions, like a single-purpose unit that is an all-in-one solution. The soekris and PC Engines firewall products come to mind. 99% of my time, I leave GENERIC (makes updating it easier with freebsd-update) alone and load the kernel modules I need. the amount of ram used with a GENERIC kernel and a "stripped" kernel to your hardware may save 2MB of disk, and 1MB of RAM. Not very worth it for the computers today where you have TB's of disk, and GB's of ram. Can I ask for more details from you why you're interested in building a custom kernel? --TJ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
question about building a custom kernel
Hi I have been reading the handbook to learn about building a custom kernel, but just wanted to ask something about gathering information about my hardware before I give it a go. The handbook suggests the command: # pciconf -lv ...which I like because it provides a clear list of components I can find out about before I try to build the new kernel. On my system, this command does print out information for quite a few components, I just wondered if this information is all I need to work from or is it not an accurate or detailed enough representation of the hardware I have in my computer. I'd really appreciate any advice on how others go about this. Jamie pgpvt6DNhLZtC.pgp Description: PGP signature
Re: Building a custom kernel
Kövesdán Gábor wrote: Hi, I'd like to build a monolithic kernel without loadable module support. I've also made it on Linux, but I haven't found such howto for FreeBSD. Is there any opportunity to do this? makeoptions MODULES_OVERRIDE="" this will only prevent kernel modules from being build, so it doesn't directly address your question. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Building a custom kernel
Kövesdán Gábor wrote: I'd like to build a monolithic kernel without loadable module support. I've also made it on Linux, but I haven't found such howto for FreeBSD. Is there any opportunity to do this? this doesn't answer your question directly but you can disable (un-)loading of modules during runtime if you set the securelevel to sth >= 1. afaik, there are some things which only work as modules so disabling modules might not be a good idea. acpi is one of them, i believe. hth, phil. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Building a custom kernel
Hi, I'd like to build a monolithic kernel without loadable module support. I've also made it on Linux, but I haven't found such howto for FreeBSD. Is there any opportunity to do this? Thanks, Gabor Kovesdan ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
