[PATCH] improve mig building guide

[Pasha (biblio)]

From: "pasha (biblio)" <pasha@bell01.com>

---
 microkernel/mach/mig/gnu_mig/building.mdwn | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/microkernel/mach/mig/gnu_mig/building.mdwn 
b/microkernel/mach/mig/gnu_mig/building.mdwn
index f335aa73..8f919aa7 100644
--- a/microkernel/mach/mig/gnu_mig/building.mdwn
+++ b/microkernel/mach/mig/gnu_mig/building.mdwn
@@ -84,7 +84,7 @@ configure:
     $ GNU=~/gnu
     $ TARGET_CPPFLAGS=-I"$GNU"/include ../configure --prefix="$GNU"
 
-If you are building on a 64 bit machine, you need to add a --target option:
+If you want to build 32-bit gnumach on a 64-bit machine, you need to add 
--target option (i686-gnu or i686-linux-gnu). mig(com) will be build as ELF64 
binary, but it will generate 32-bit code for gnumach:
 
     $ GNU=~/gnu
     $ TARGET_CPPFLAGS=-I"$GNU"/include ../configure --prefix="$GNU" 
--target=i686-gnu TARGET_CC=i686-linux-gnu-gcc
@@ -93,6 +93,11 @@ Build and install the Mach Interface Generator into _$GNU_ 
(i.e. _~/gnu/_ in our
 
     $ make all install
 
+In case of --target 32-bit, mig might be installed as i686-(linux)-gnu-mig. 
Create a symbolic link for mig:
+
+       $ cd ~/gnu/bin/
+       $ ln -s i686-linux-gnu-mig mig
+
 To make your _mig_ binary easily available, you should append something like
 the following to e.g. your _~/.bash\_profile_:
 
@@ -102,3 +107,12 @@ the following to e.g. your _~/.bash\_profile_:
 If you already have e.g. _~/bin_ in your _$PATH_, you could also create a 
symbolic link:
 
     $ ln -s ~/gnu/bin/mig ~/bin/
+
+For advance users, if you want to build mig(com) as ELF32 binary to copy to a 
32-bit machine or any other purposes, you need to add --host, LD, CC options:
+
+       $ TARGET_CPPFLAGS=-I"$GNU"/include ../configure --prefix="$GNU" 
--target=i686-linux-gnu TARGET_CC=i686-linux-gnu-gcc \
+         --host=i686-gnu LD=i686-linux-gnu-ld CC=i686-linux-gnu-gcc
+
+You may verify using:
+
+       $ readelf -h ~/gnu/libexec/i686-linux-gnu-migcom
-- 
2.39.2