How does one add a patch to the kernel?

reddyenumber4 · 2009-03-13 07:06:31

I need to patch the kernel to enable functionality for an IR receiver, and I can't seem to find clear instructions on adding a patch.

There are lots of posts about upgrading to a newer kernel, but I can't seem to find anything about just adding a specific patch file.

Any help or a pointer to a post or wiki entry that explains this would be greatly appreciated.

For reference, my specific issue was posted here:

http://bbs.archlinux.org/viewtopic.php?id=66144

Thanks in advance.

bangkok_manouel · 2009-03-13 07:30:42

here's the ARCH kernel PKGBUILD:

# $Id$
# Maintainer: Tobias Powalowski <tpowa@archlinux.org>
# Maintainer: Thomas Baechler <thomas@archlinux.org>
pkgname=kernel26                # Build stock -ARCH kernel
# pkgname=kernel26-custom       # Build kernel with a different name
_kernelname=${pkgname#kernel26}
_basekernel=2.6.28
pkgver=${_basekernel}.7
pkgrel=2
_patchname="patch-${pkgver}-${pkgrel}-ARCH"
pkgdesc="The Linux Kernel and modules"
arch=(i686 x86_64)
license=('GPL2')
groups=('base')
url="http://www.kernel.org"
backup=(etc/mkinitcpio.d/${pkgname}.preset)
depends=('coreutils' 'kernel26-firmware>=2.6.28' 'module-init-tools' 'mkinitcpio>=0.5.20')
# pwc, ieee80211 and hostap-driver26 modules are included in kernel26 now
# nforce package support was abandoned by nvidia, kernel modules should cover everything now.
# kernel24 support is dropped since glibc24
replaces=('kernel24' 'kernel24-scsi' 'kernel26-scsi'
          'alsa-driver' 'ieee80211' 'hostap-driver26'
          'pwc' 'nforce' 'squashfs' 'unionfs' 'ivtv'
          'zd1211' 'kvm-modules' 'iwlwifi' 'rt2x00-cvs'
          'gspcav1' 'atl2' 'wlan-ng26')
install=kernel26.install
source=(ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-$_basekernel.tar.bz2
        ftp://ftp.archlinux.org/other/kernel26/${_patchname}.bz2
        # the main kernel config files
        config config.x86_64
        # standard config files for mkinitcpio ramdisk
        kernel26.preset)
optdepends=('crda: to set the correct wireless channels of your country')
md5sums=('d351e44709c9810b85e29b877f50968a'
         'e535d668afb04a590f03a47356794579'
         '3c47674afeae26616acd9dfc4060bd02'
         '1f0005febea457f47f26af1726dbf1b2'
         '25584700a0a679542929c4bed31433b6')

build() {
  KARCH=x86

  cd ${srcdir}/linux-$_basekernel
  # Add -ARCH patches
  # See http://projects.archlinux.org/git/?p=linux-2.6-ARCH.git;a=summary
  patch -Np1 -i ${srcdir}/${_patchname} || return 1

  if [ "$CARCH" = "x86_64" ]; then
    cat ../config.x86_64 >./.config
  else
    cat ../config >./.config
  fi
  if [ "${_kernelname}" != "" ]; then
    sed -i "s|CONFIG_LOCALVERSION=.*|CONFIG_LOCALVERSION=\"${_kernelname}\"|g" ./.config
  fi
  # get kernel version  
  make prepare
  _kernver="$(make kernelrelease)"
  # load configuration
  # Configure the kernel. Replace the line below with one of your choice.
  #make menuconfig # CLI menu for configuration
  #make xconfig # X-based configuration
  #make oldconfig # using old config from previous kernel version
  # ... or manually edit .config
  ####################
  # stop here
  # this is useful to configure the kernel
  #msg "Stopping build"
  #return 1
  ####################
  yes "" | make config
  # build!
  make bzImage modules || return 1
  mkdir -p ${pkgdir}/{lib/modules,boot}
  make INSTALL_MOD_PATH=${pkgdir} modules_install || return 1
  cp System.map ${pkgdir}/boot/System.map26${_kernelname}
  cp arch/$KARCH/boot/bzImage ${pkgdir}/boot/vmlinuz26${_kernelname}
  install -D -m644 Makefile \
    ${pkgdir}/usr/src/linux-${_kernver}/Makefile
  install -D -m644 kernel/Makefile \
    ${pkgdir}/usr/src/linux-${_kernver}/kernel/Makefile
  install -D -m644 .config \
    ${pkgdir}/usr/src/linux-${_kernver}/.config
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/include

  for i in acpi asm-{generic,x86} config linux math-emu media net pcmcia scsi sound video; do
    cp -a include/$i ${pkgdir}/usr/src/linux-${_kernver}/include/
  done

  # copy arch includes for external modules
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/arch/x86
  cp -a arch/x86/include ${pkgdir}/usr/src/linux-${_kernver}/arch/x86/

  # copy files necessary for later builds, like nvidia and vmware
  cp Module.symvers ${pkgdir}/usr/src/linux-${_kernver}
  cp -a scripts ${pkgdir}/usr/src/linux-${_kernver}
  # fix permissions on scripts dir
  chmod og-w -R ${pkgdir}/usr/src/linux-${_kernver}/scripts
  #mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/.tmp_versions

  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/arch/$KARCH/kernel

  cp arch/$KARCH/Makefile ${pkgdir}/usr/src/linux-${_kernver}/arch/$KARCH/
  if [ "$CARCH" = "i686" ]; then
    cp arch/$KARCH/Makefile_32.cpu ${pkgdir}/usr/src/linux-${_kernver}/arch/$KARCH/
  fi
  cp arch/$KARCH/kernel/asm-offsets.s ${pkgdir}/usr/src/linux-${_kernver}/arch/$KARCH/kernel/

  # add headers for lirc package
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/video
  cp drivers/media/video/*.h  ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/video/
  for i in bt8xx cpia2 cx25840 cx88 em28xx et61x251 pwc saa7134 sn9c102 usbvideo zc0301; do
   mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/video/$i
   cp -a drivers/media/video/$i/*.h ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/video/$i
  done
  # add dm headers
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/drivers/md
  cp drivers/md/*.h  ${pkgdir}/usr/src/linux-${_kernver}/drivers/md
  # add inotify.h
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/include/linux
  cp include/linux/inotify.h ${pkgdir}/usr/src/linux-${_kernver}/include/linux/
  # add CLUSTERIP file for iptables
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/net/ipv4/netfilter/
  # add wireless headers
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/net/mac80211/
  cp net/mac80211/*.h ${pkgdir}/usr/src/linux-${_kernver}/net/mac80211/
  # add dvb headers for external modules
  # in reference to:
  # http://bugs.archlinux.org/task/9912
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/dvb/dvb-core
  cp drivers/media/dvb/dvb-core/*.h ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/dvb/dvb-core/
  # add dvb headers for external modules
  # in reference to:
  # http://bugs.archlinux.org/task/11194
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/include/config/dvb/
  cp include/config/dvb/*.h ${pkgdir}/usr/src/linux-${_kernver}/include/config/dvb/
  # add dvb headers for http://mcentral.de/hg/~mrec/em28xx-new
  # in reference to:
  # http://bugs.archlinux.org/task/13146
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/dvb/frontends/
  cp drivers/media/dvb/frontends/lgdt330x.h ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/dvb/frontends/
  cp drivers/media/video/msp3400-driver.h ${pkgdir}/usr/src/linux-${_kernver}/drivers/media/dvb/frontends/
  # add xfs and shmem for aufs building
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/fs/xfs
  mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/mm
  cp fs/xfs/xfs_sb.h ${pkgdir}/usr/src/linux-${_kernver}/fs/xfs/xfs_sb.h
  # add vmlinux
  cp vmlinux ${pkgdir}/usr/src/linux-${_kernver}
  # copy in Kconfig files
  for i in `find . -name "Kconfig*"`; do 
    mkdir -p ${pkgdir}/usr/src/linux-${_kernver}/`echo $i | sed 's|/Kconfig.*||'`
    cp $i ${pkgdir}/usr/src/linux-${_kernver}/$i
  done

  cd ${pkgdir}/usr/src/linux-${_kernver}/include && ln -s asm-$KARCH asm

  chown -R root.root ${pkgdir}/usr/src/linux-${_kernver}
  find ${pkgdir}/usr/src/linux-${_kernver} -type d -exec chmod 755 {} \;
  cd ${pkgdir}/lib/modules/${_kernver} && \
    (rm -f source build; ln -sf ../../../usr/src/linux-${_kernver} build)
  # install fallback mkinitcpio.conf file and preset file for kernel
  install -m644 -D ${srcdir}/kernel26.preset ${pkgdir}/etc/mkinitcpio.d/${pkgname}.preset || return 1
  # set correct depmod command for install
  sed \
    -e  "s/KERNEL_NAME=.*/KERNEL_NAME=${_kernelname}/g" \
    -e  "s/KERNEL_VERSION=.*/KERNEL_VERSION=${_kernver}/g" \
    -i $startdir/kernel26.install
  sed \
    -e "s|source .*|source /etc/mkinitcpio.d/kernel26${_kernelname}.kver|g" \
    -e "s|default_image=.*|default_image=\"/boot/${pkgname}.img\"|g" \
    -e "s|fallback_image=.*|fallback_image=\"/boot/${pkgname}-fallback.img\"|g" \
    -i ${pkgdir}/etc/mkinitcpio.d/${pkgname}.preset

  echo -e "# DO NOT EDIT THIS FILE\nALL_kver='${_kernver}'" > ${startdir}/pkg/etc/mkinitcpio.d/${pkgname}.kver
  # remove unneeded architectures
  rm -rf ${pkgdir}/usr/src/linux-${_kernver}/arch/{alpha,arm,arm26,avr32,blackfin,cris,frv,h8300,ia64,m32r,m68k,m68knommu,mips,mn10300,parisc,powerpc,ppc,s390,sh,sh64,sparc,sparc64,um,v850,xtensa}
  # remove the firmware
  rm -rf ${pkgdir}/lib/firmware
}

Arch's stock kernel is patched. You take this as an example and adapt it to your needs.
1. add the source of your patch in the source array:

source=(ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-$_basekernel.tar.bz2
        ftp://ftp.archlinux.org/other/kernel26/${_patchname}.bz2
        # the main kernel config files
        config config.x86_64
        # standard config files for mkinitcpio ramdisk
        kernel26.preset)

it can be the file name or an url. if it's a file, be sure to place it in the same folder as your PKGBUILD.
2. Patching process:

patch -Np1 -i ${srcdir}/${_patchname} || return 1

That's the one for the ARCH patch. Simply copy/paste this line and modify it:

patch -Np1 -i ${srcdir}/your_patch_name || return 1

That's it.
One more thing, it is very likely that your patch will require a modification of the kernel config file.
Therefore, you'll have to use something like:

make menuconfig

instead of

yes "" | make config

this will bring you to a menu where you can modify your kernel config. do it, save your config and the build will start.

reddyenumber4 · 2009-03-13 07:44:20

Thanks a lot, I have exams in the morning, but I'll test this out later tonight.

Arch Linux

#1 2009-03-13 07:06:31

How does one add a patch to the kernel?

#2 2009-03-13 07:30:42

Re: How does one add a patch to the kernel?

#3 2009-03-13 07:44:20

Re: How does one add a patch to the kernel?

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