Posts

mips64el-unknown-linux-gnu cross toolchain building

NOTE: I just updated the command at the bottom, again. No big change. Now all should be good to go, including building on PS3, which is big endian.

Crossdev is a great tool. Thanks to vapier.
However, it may not work in all circumstances, although the problems may not lie in crossdev itself. For example, when creating mips64el-unknown-linux-gnu cross toolchain.
The problems happen when building glibc headers. Because at that time, we don't have cross gcc yet. So some gcc options only cross gcc supports or some macros only cross gcc defines can't be used.
Also happen when building gcc on big endian machines. Because of the erroneous LD_LIBRARY_PATH setting, cc1 generated in stage 1 will try to load libgcc_s.so.1 generated in stage 1, which is little endian.
So I made some work-arounds. These are the three patches needed:
one patch to src_compile.eblit
a second patch to src_install.eblit
a third patch to gcc ebuild
These are all small changes, but took me a lot of time to investigate.

To …

MIPS N32 patch for xulrunner(firefox)

Finally, I have produced some results. I have watched 6 seasons of 24 and 2 seasons of Friends since late last month. So this is delayed. :P
The patch is here.
I think it still need some tweaks, you can always get the latest patch in my loongson overlay on http://www.gentoo-cn.org/gitweb.

The produced xulrunner could run a little example:
http://dev.gentoo.org/~r0bertz/xulrunner/myapp.tar.bz2
(untar the tarball, cd myapp && xulrunner-1.9 application.ini)

However, I haven't got a fully functioning firefox yet.
Some font size is extremely large. And sometimes bus error.

I have noticed that I have used -O3 to compile it.
I will try -O2/-O1 later and see if it still bus error.

glibc doesn't build with linux-header-2.6.28 on loongson

Update: It is said that this problem has already been fixed. I will test it later.

Actually I intended to send this to LKML, but just before I was about to send I found there was already some discussions about this . So instead I decided to just post it here.

To make long story short, please take a look at these two files first:

The first file, which will become part of /usr/include/endian.h. This file defines both __LITTLE_ENDIAN and __BIG_ENDIAN. And this file will be included by the second file.

The second file, which will be /usr/include/linux/byteorder.h

Obviously, this test in the second file will fail:
#if defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)
# error Fix asm/byteorder.h to define one endianness
#endif It seems that there is an inconsistency between Linux and glibc on handling __LITTLE_ENDIAN and __BIG_ENDIAN. Linux treats them like a flag, while glibc treats them like a value. glibc uses __BYTE_ORDER to determine the endianness.

This problem must be solved, or any us…

Works I have done related to Loongson in recent months

I got a donation of a Lemote Loongson 2F box somewhere around July this year and have been working on it in my spare time since I got it.

The other day I made a summary about what I have done so far and posted it on Lemote's bbs. The links is http://www.lemote.com/bbs/viewthread.php?tid=20134
My work involves toolchain, kernel, xorg-server MIPS or Loongson support and userland library/application gcc 4.4 patch.

The most prominent achievement so far is an N32 ABI stage3 (well, actually just a tarball, not made using catalyst) optimized for Loongson 2F with MIPS PLT support. It is actually not that easy as you would've imagined, N32 has many problems as you can see from the above posted link. I posted it on Lemote's bbs along with some instructions of how to use it: http://www.lemote.com/bbs/viewthread.php?tid=20125

According to some testers, performance of some applications in this system has an up to 30% increase comparing with the performance of the same apps in system Using …

EAPI 2: SRC_URI Arrows implementation in portage

Background: http://ciaranm.wordpress.com/2008/09/28/eapi-2-src_uri-arrows/

Today I found arrows in SRC_URI is not working in my box, so I took a look at the code, found something, and sent this:
http://www.nabble.com/a-little-patch-related-to-arrow-in-SRC_URI-td20732745.html

However, as Zac pointed out, the better solution is not to define your own fetch and resume command but rely on the default one.

The default ones are defined in /etc/make.globals:
FETCHCOMMAND="/usr/bin/wget -t 5 -T 60 --passive-ftp -O \"\${DISTDIR}/\${FILE}\" \"\${URI}\""
RESUMECOMMAND="/usr/bin/wget -c -t 5 -T 60 --passive-ftp -O \"\${DISTDIR}/\${FILE}\" \"\${URI}\""The rules of thumb is to make sure you save the file at ${DISTDIR}/${FILE}, since FILE is just the file name, doesn't include path.

Previously I have fetch and resume command defined in make.conf, and have used "-P ${DISTDIR}" instead of "-O ${DISTDIR}/${FILE}". Maybe portag…

A problem in Loongson 2F specific integer operation instruction patch

I have reported on gcc mailing list.
http://gcc.gnu.org/ml/gcc/2008-11/msg00076.html

Also I found the solution:
http://gcc.gnu.org/ml/gcc/2008-11/msg00087.html

Now I have built gcc-4.4 with my modified patch with "-march=mips3", and am building itself again using "-march=loongson2f".

Note that enabling -O2 in later stages is not working yet. Please check this bug report for more information if you are interested:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38052

EDIT:
just heard from Kumba, this flag used together with -O1 will trigger this bug:
-foptimize-sibling-calls
Optimize sibling and tail recursive calls.

Enabled at levels -O2, -O3, -Os.

The modified gcc 4.4 ebuild is here and some relevant libraries here.

Gcc 4.4 Loongson 2F specific integer multiply/divide instruction patch

http://gcc.gnu.org/ml/gcc-patches/2008-11/msg00273.html
I have put it in my loongson overlay.
BTW, the gcc svn ebuild is from dirtyepic's overlay. Thanks, ;)

zhangle@2f ~ $ cat hello.c
#include<stdio.h>
int mul(){
unsigned long a = 0xffffffff;
unsigned long b = 0xf;
return a * b;
}
zhangle@2f ~ $ gcc -march=loongson2f hello.c -S
zhangle@2f ~ $ gcc -march=mips3 hello.c -S -o hello-mips3.s
zhangle@2f ~ $ diff -u hello.s hello-mips3.s
--- hello.s 2008-11-08 18:16:52.000000000 +0800
+++ hello-mips3.s 2008-11-08 18:16:55.000000000 +0800
@@ -25,7 +25,8 @@
sw $2,8($fp)
lw $3,12($fp)
lw $2,8($fp)
- multu.g $2,$3,$2
+ mult $3,$2
+ mflo $2
move $sp,$fp
lw $fp,20($sp)
addiu $sp,$sp,24

improvements (Gentoo specific) to distcc zeroconf support

distcc's got zeroconf support
That is cool!However, there are problems (althouth not everyone got these problems).
One of them is that if you have multiple version of gcc's or even
cross compilers, distcc clients can't discover them, since distccd will
only register your current active gcc.
And if you want to change your native compiler's version, you must
restart distccd in order to let it take effect.Having multiple gcc's may not be common in other distribution, but
this is common in gentoo.
This is what I have on my x86 notebook:
gcc-config -l
[1] i686-pc-linux-gnu-4.3.1 *
[2] mipsel-unknown-linux-gnu-4.3.0-alpha20080731
[3] mipsel-unknown-linux-gnu-4.3.1
[4] mipsel-unknown-linux-gnu-4.4.0-alpha20080718 *
[5] mipsel-unknown-linux-gnu-4.4.0-alpha20080801
[6] powerpc-unknown-linux-gnu-4.2.3 *So I made a little patch:
https://bugs.gentoo.org/show_bug.cgi?id=233843Hope there will be a distcc-2.18.3-r14 or distcc-3.0_rc4 in tree soon, ;)

make awstats support Gentoo

It makes me very uncomfortable that awstat-6.7-r2 in tree does not
have support for Gentoo
So I made a little patch and a little icon.
http://tinyurl.com/5dj2x3I have already tested it on www.gentoo-cn.org. It works.
Hope upstream would accept it soon.

portage-2.2 preserve-libs FEATURES explained

Maybe I am not the right person to write about it. But I felt the necessity to write about it. So I will just write something about preserve-libs, leaving other FEATURES to more competent people.

Portage-2.2 has already entered unstable tree. Many people has started using it. It has many new features, like preserve-libs, sets, license filter and so on. Please check README and RELEASE-NOTES for a complete list. I will only talk about preserve-libs.

To understand why we need it, we have to know some background information.
First of all, applications are not built from scratch. Any non trivial apps use lot of libraries.
In GNU/Linux, most of them are shared libraries, i.e. .so files.
You can use `ldd /usr/bin/mplayer` to check what shared libraries an app has been linked to, replace mplayer to whatever program you'd like to check.
Shared libraries have versions.
E.g. /usr/lib/libavformat.so.51, here 51 denotes its version.
After upgrading, the version number may change.
E.g. /usr/lib/libavfor…

Some updates (docs, loongson, as-needed)

1. Documentation get updates regularly as usual.
http://www.gentoo-cn.org/gitweb/?p=gentoo-cn;a=summary

2. Our table now can distinguish between file owner and file last updater when the file in question need to be updated. If the last updater is the owner, there will be an email link on the name; otherwise, there will be no link, but the name will be in red. The name is in the last column.
http://www.gentoo-cn.org/trads/
http://rubyurl.com/0BD4

3. I will get my loongson 2f box soon, :-D

4. Just fixed an as-needed problem:
http://bugs.gentoo.org/show_bug.cgi?id=225117
http://www.gentoo.org/proj/en/qa/asneeded.xml

Old story

Although I don't know the direct cause of council's decision this time, it reminds me of an old story.
http://r0bertz.blogspot.com/2007/01/be-careful-when-you-are-on-paludis.html

Quote some Diego's words:
Don’t think we woke up this morning and decided to get rid of any developer. We considered this for a quite long time. Over all, I think the decision was took after a too long time.

You can criticise, you can joke, but if the people you joke upon don’t laugh with you at the joke, then apologise and stop it!

Some updates about loongson

1. Gcc's support for loongson is coming:
http://gcc.gnu.org/ml/gcc/2008-04/msg00551.html

2. Lemote Loongson 2F box's release has been postponed to June 30.
http://202.201.0.147/Html/inner/2008-4/11/201803589.html

For those who want to order 2F box: I have talked to 2F box's product manager, he recommended sending email to sales@lemote.com directly.

That's it, ;)

PS: Lemote has Loongson laptop, too.