blob: b34de8e660b0366d8f127b0e78f8c2c6c05af5d7 [file] [log] [blame]
--- make.conf.example
+++ make.conf.example
@@ -22,6 +22,13 @@
# Example:
#USE="X gtk gnome -alsa"
+# Host Setting
+# ============
+#
+# All PowerPC systems should use this host setting:
+
+CHOST="powerpc-unknown-linux-gnu"
+
# Host and optimization settings
# ==============================
#
@@ -39,10 +46,56 @@
# -frecord-gcc-switches, since otherwise the check could result in false
# positive results.
#
-# Please refer to the GCC manual for a list of possible values.
+# -mcpu=<cpu-type> for PowerPC systems selects the type of processor you want
+# to optimize your code for. Code generated under those options will run best
+# on that processor, and may not run at all on others.
+#
+# GCC 3.4 supports many powerpc processor types including: 401, 403, 405,
+# 405fp, 440, 440fp, 505, 601, 602, 603, 603e, 604, 604e, 620, 630, 740, 7400,
+# 7450, 750, 801, 821, 823, 860, 970, 8540, common, ec603e, G3, G4, G5, power,
+# power2, power3, power4, power5, powerpc, powerpc64, rios, rios1, rios2, rsc,
+# and rs64a
+#
+# Recommended settings for GCC 3.4 only :
+#
+# -maltivec enables optional altivec support and should be used
+# only for G4 processors, on GCC 3.2 or newer. It also requires that you have
+# the alitvec option compiled into your kernel to take full advantage of this
+# feature. Note: you should also include -mabi=altivec flag if using this
+# option.
+#
+# The newer gcc has a stricter aliasing ruleset that makes type punned
+# expression faulty compiled if -fstrict-aliasing is enabled.
+# That option is implied by -O2 -Os and -O3. Make SURE you don't have that
+# option enabled by adding -fno-strict-aliasing to your CFLAGS and CXXFLAGS
+#
+# Long term testing has shown that -O3 opts can be unreliable on G4's but work
+# on G3 series processors or earlier.
#
-#CFLAGS="-O2 -pipe"
+# The following is the suggested CFLAGS for a generic G4 cpu
#
+#CFLAGS="-O2 -pipe -mcpu=G4 -maltivec -mabi=altivec -fno-strict-aliasing"
+#
+#
+# All non G4 PPC boxen should choose this next option. It will work fine for
+# all G3 and pre machines. (note it will not hurt pre G3 machines either to
+# use this mcpu option as it is the default for gcc 3.2.x anyway)
+#
+#CFLAGS="-O2 -pipe -mcpu=G3 -fno-strict-aliasing"
+
+# Recommended settings for GCC 2.95.3 only (Gentoo 1.2 or older):
+#
+# PowerPC 750 > up: this works on G3's and G4s, gcc 2.95.3 doesn't make the
+# distinction between G3 and G4, so this is fine for all NewWorld machines, if
+# you use yaboot to boot you should select this option
+#
+#CFLAGS="-O2 -pipe -mcpu=750 -mpowerpc-gfxopt -mmultiple -mstring"
+#
+# This will run on all other processors, by building more generic code This is
+# safe for all PPC machines running gcc 2.95.3, and works for all OldWorld
+# machines - if you use BootX to boot you should select this option
+#CFLAGS="-O2 -pipe -mmultiple -mstring"
+
# If you set a CFLAGS above, then this line will set your default C++ flags to
# the same settings.
#CXXFLAGS="${CFLAGS}"
@@ -76,7 +129,10 @@
# DO NOT PUT ANYTHING BUT YOUR SPECIFIC ~ARCHITECTURE IN THE LIST.
# IF YOU ARE UNSURE OF YOUR ARCH, OR THE IMPLICATIONS, DO NOT MODIFY THIS.
#
-#ACCEPT_KEYWORDS="~arch"
+# Note: this really shouldn't be enabled until _AFTER_ you bootstrap and emerge
+# system. If you want the testing things update after these steps are completed.
+#
+#ACCEPT_KEYWORDS="~ppc"
# ACCEPT_LICENSE is used to mask packages based on licensing restrictions.
# It may contain both license and group names, where group names are