RFC-Compile-Kernel+Qemu-on-RHEL.txt

Most of you should know about this, but it should be FAQ for beginner.
# Comments are welcome.

== Compile Kernel/Qemu on RHEL ==
   by Amos Kong <akong@redhat.com>
   Feb 28, 2013

++ Compile qemu-kvm-rhel6/7 by brew:
  # cd qemu-kvm-rhel6/redhat
  # kinit (configure Red Hat Kerberos first, [0])
  # echo "e1000fix" > ../localversion
  # make rh-brew

++ Compile kernel-rhel6/7 by brew:
  # cd kernel/redhat
  # kinit
  # echo ".e1000fix" > ../localversion
  # make rh-brew

+ Compile upstream kernel on RHEL
  install: gcc, glibc-devel, kernel-devel, kernel-headers, etc
  common steps: make menuconfig; make bzImage; make modules; make
                modules_install; make install

++ Compile upstream qemu on RHEL
  steps: resolve package dependences, configure, compile

  steps to resolve dependence issue:
  - find the package name:
    read configure error to know what's lack, you can read configure
    sentences to know more detail, yum / rpm / etc can help to determine
    the package name. 
  - find related devel package
    most of time, the devel packages' name have a '-devel' postfix
  - install package and devel package
    check if package exists in host by "rpm -qa |grep $package"
    install packages from yum source (brew way, but not always available),
    brewweb [1], brew packages catalog (same with brewweb, but quicker)[2],
    compile from source(not recommend for RHEL testing), etc.

Prepare: get qemu code from upstream repo
  [root@ibm-x3650m4-05 ~]# git clone git://git.qemu.org/qemu.git
  [root@ibm-x3650m4-05 ~]# cd qemu

Example 0: get package name from error message with experience, gcc and devel package is installed by yum
  [root@ibm-x3650m4-05 qemu]# ./configure 
  ERROR: "cc" either does not exist or does not work
  [root@ibm-x3650m4-05 qemu]# yum install gcc glibc-devel   

Example 1: find the package name from yum source, install packages by yum
  [root@ibm-x3650m4-05 qemu]# ./configure 
  glib-2.12 required to compile QEMU
  [root@ibm-x3650m4-05 qemu]# yum search glib|grep 2 |grep devel
  glib2-devel.i686 : A library of handy utility functions
  glib2-devel.x86_64 : A library of handy utility functions
  [root@ibm-x3650m4-05 qemu]# yum install glib2-devel -y

Example 2: search the dependence files in ./configure, and find package name by "yum provides .."
  [root@ibm-x3650m4-05 qemu]# ./configure
  Error: zlib check failed
  Make sure to have the zlib libs and headers installed.
  
  [root@ibm-x3650m4-05 qemu]# less ./configure
  ##########################################
  # zlib check
  if test "$zlib" != "no" ; then
      cat > $TMPC << EOF
  #include <zlib.h>
  int main(void) { zlibVersion(); return 0; }
  ...
          echo "Error: zlib check failed"

  [root@ibm-x3650m4-05 qemu]# yum provides */zlib.h
  zlib-devel-1.2.7-9.el7.x86_64 : Header files and libraries for Zlib development
  Filename    : /usr/include/zlib.h
  
  [root@ibm-x3650m4-05 qemu]# yum install zlib-devel -y

Example 3: find packages from brew package catalog
  (http://download.englab.nay.redhat.com/brewroot//packages/ + packagename + sub-version + ...)
  [root@ibm-x3650m4-05 qemu]# ./configure 
  ERROR: pixman not present. Your options:
    (1) Preferred: Install the pixman devel package (any recent
        distro should have packages as Xorg needs pixman too).
    (2) Fetch the pixman submodule, using:
        git submodule update --init pixman

  [root@ibm-x3650m4-05 qemu]# rpm -qa |grep pixman
    pixman-0.26.2-5.el7.x86_64
     
  [root@ibm-x3650m4-05 qemu]# wget http://download.englab.nay.redhat.com/brewroot//packages/pixman/0.26.2/5.el7/x86_64/pixman-devel-0.26.2-5.el7.x86_64.rpm
  [root@ibm-x3650m4-05 qemu]# yum install pixman-devel-0.26.2-5.el7.x86_64.rpm -y

Example 4: find packages from brewweb
  [root@ibm-x3650m4-05 qemu]# ./configure --enable-spice
  ERROR: User requested feature spice
  ERROR: configure was not able to find it

  search "spice-server" in brewweb [1], download and install the right spice-server-devel package

Execute compile: (multiple threads)
  [root@ibm-x3650m4-05 qemu]# make -j 8


[0] https://home.corp.redhat.com/wiki/new-developer-quickstart-guide-red-hat
[1] http://brewweb.devel.redhat.com/
[2] http://download.englab.nay.redhat.com/brewroot//packages/