svn commit: r203413 - user/imp/tbemd
Warner Losh
imp at FreeBSD.org
Wed Feb 3 03:26:01 UTC 2010
Author: imp
Date: Wed Feb 3 03:26:00 2010
New Revision: 203413
URL: http://svn.freebsd.org/changeset/base/203413
Log:
Describe what I'm going to do to kill TARGET_BIG_ENDIAN
Added:
user/imp/tbemd/README-BRANCH
Added: user/imp/tbemd/README-BRANCH
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ user/imp/tbemd/README-BRANCH Wed Feb 3 03:26:00 2010 (r203413)
@@ -0,0 +1,24 @@
+TARGET_BIG_ENDIAN must die
+
+Changes in MACHINE_ARCH:
+
+mips (big endian) mipseb
+mips (little endian) mipsel
+arm (little endian) arm For historical reasons
+arm (big endian) armeb
+
+What we call today MACHINE_ARCH is really MACHINE_CPUARCH. This is
+called MACHINE_CPU on NetBSD, but FreeBSD already uses MACHINE_CPU for
+other purposes. In general $MACHINE_ARCH -> $MACHINE_CPUARCH in most
+places in the tree. MACHINE_CPUARCH is defined in bsd.own.mk, since
+it is dependent on the bsd tree, actually. All the translation from
+MACHINE_ARCH to MACHINE_CPUARCH assumes that all members of that
+family are supported by one set of files on FreeBSD. So mips files
+have support for both big and little endian. But MACHINE_ARCH
+determines the default binaries that are generated.
+
+We'll likely need to have a MACHINE_ABI at some point. Both MIPS and
+ARM have multiple ABIs, and we'll need something to be the default,
+and different CPUs within a family might have different defaults.
+Etc. Plus there's t he need for multilib. However, issues like this
+are beyond the scope of this branch.
More information about the svn-src-user
mailing list