The very first task is to set up a sane environment in which to perform the build. These environmental settings apply to the initial Temptools phase, though most will also be carried through into the Chroot phase. But first, a lesson that many folks have learned the hard way:

Create a specific user and group in which to perform the build of the Temptools phase. Let's call them something creative like `build'. As root:

groupadd build
useradd -s /bin/bash -g build -m -k /dev/null build
passwd build

Decide where you want to build and install the system to. This doesn't have to be a partition, it can be anywhere, under $HOME, /mnt, /tmp or wherever you like, as long as there is plenty of space there (FIXME how much?). The location you've chosen to build the system will be assigned to the $SYSROOT variable below. Once the build has finished, the entire root file system image may be transferred to its intended final destination.

The following steps are taken to ensure a sane shell environment in which to work in. Your build script should, in practice, inherit these settings but it would be wise to at least sanity check the variables yourself when writing your script. Now login as user `build' and create the needed bash startup files and config.site. Then source the files:

su - build

cat > ~/.bash_profile << "EOF"
exec env -i HOME=$HOME TERM=$TERM PS1='\u:\w\$ ' /bin/bash
EOF

cat > ~/.bashrc << "EOF"
TT_PFX=/temptools
CONFIG_SHELL=${TT_PFX}/bin/bash
CONFIG_SITE=${HOME}/config.site
DIY_TARGET=i686-diy-linux-gnu
BIARCH=NO
if [ "$BIARCH" = YES ]; then
  if ! echo $DIY_TARGET | grep ^x86_64 >/dev/null; then
    echo Warning: no BIARCH support for target $DIY_TARGET !
  else
    export DIR_64=64
  fi
fi
LC_ALL=C
LDFLAGS="-s"
PATH=${TT_PFX}/bin:/bin:/usr/bin
SYSROOT=/mnt/sysroot
TZ='Australia/Sydney'
export TT_PFX CONFIG_SHELL CONFIG_SITE DIY_TARGET BIARCH LC_ALL LDFLAGS PATH SYSROOT TZ
#export MAKEFLAGS="-j3"
set +o hashall 2>/dev/null || set -o nohash
umask 022
BINUTILS_VER=2.18
GCC_VER=4.2.4
GLIBC_VER=2.7
export BINUTILS_VER GCC_VER GLIBC_VER
EOF

cat > ~/config.site << "EOF"
test "$prefix" = NONE && prefix=${TT_PFX}
test -z "$CFLAGS" && CFLAGS="-O2 -pipe"
test -z "$CXXFLAGS" && CXXFLAGS=${CFLAGS}
enable_nls=no
EOF

source ~/.bash_profile

# Add this section ONLY when using the original (deprecated) build method!
cat >> ~/.bashrc << "EOF"
export DIY_ARCH=i386
EOF

source ~/.bash_profile

FIXME explain rationale for each item above

Now become root and set up the sysroot area:

install -dv ${SYSROOT}${TT_PFX}/src/{tarballs,patches}
ln -sv ${SYSROOT}${TT_PFX} /
chown -Rv build ${SYSROOT}${TT_PFX}

Now exit the su (root) login and from this point onwards the environment should be sane enough to build the temptools phase whenever you login as user `build'. Dump all the needed tarballs and patches into their respective dirs. Now you're ready to rock.

Here is a list of source packages used in the build. This information is extracted into the aforementioned packagedata file for easy parsing and/or conversion into a wget script:

Patches used in the Reference Build can be downloaded from http://downloads.diy-linux.org/patches/. Be sure to look in the "PM" subdirectory for Package Management related patches, "ppc" subdirectory for PowerPC related patches, etc.