Monday, February 11, 2008

Building and installing the DRM/DRI/X stack

When I work on the X stack I typically compile and install all the packages into an install prefix in my home directory, typically $HOME/install. That way I can keep my system packages intact and even have multiple versions or branches of the stack installed. This recently got a lot easier with the autoconfiscation of mesa so I decided to write up a short tutorial on how to do this. I like to first uninstall my distributions development packages for the projects involved just to make sure the configure scripts don't pick up a wrong version. For Fedora this is something like

rpm -e libdrm-devel xorg-x11-server-devel
In previous Fedora releases, the xorg-x11-server-devel package was called xorg-x11-server-sdk.

To bring up an X server with DRI, we'll need to clone the drm, mesa, xserver, xf86-input-evdev and a video driver repository. By default, git will check out the master branch when you clone, but if you want to try a different branch of a repository you have to say

git checkout -b intel-batchbuffer origin/intel-batchbuffer

after cloning to check out the intel-batchbuffer branch

First step is building drm

git clone git://git.freedesktop.org/git/mesa/drm
cd drm
./autogen.sh --prefix=$HOME/install
make
make -C linux-core
make install

The make -C linux-core step will build the DRM modules for the current kernel and needs the kernel-devel package on Fedora.

For the rest of the builds, we'll need this environment variable set:

export PKG_CONFIG_PATH=$HOME/install/lib/pkgconfig

Now that we have libdrm built and installed we can build mesa. Mesa doesn't use automake and doesn't come with an autogen.sh script so we have to bootstrap it a little differently:

git clone git://git.freedesktop.org/git/mesa/mesa
cd mesa
aclocal
autoconf
./configure --prefix=$HOME/install --with-driver=dri --with-dri-driverdir=$HOME/install/lib/dri
make
make install

Optionally, pass --disable-glu --disable-glw to the configure script to cut down build time a bit if you don't need these libraries (who does?).

Now we can build the X server. The configure script doesn't pick a good default for the font path, and the X server is going to bitch about this when we try to start it. I find that it's easiest just to built in the couple of core fonts the X server needs:

git clone git://git.freedesktop.org/git/xorg/xserver
cd xserver
./autogen.sh --enable-builtin-fonts --prefix=$HOME/install --with-mesa-source=$HOME/src/mesa
make
make install

With the X server installed in the prefix, we can start building drivers. The X server installs a couple of autoconf macros that aclocal needs to be pointed to, so for building drivers we need to set the ACLOCAL variable to:

export ACLOCAL="aclocal -I$HOME/install/share/aclocal"
Having set this, building the intel and evdev drivers is easy:

git clone git://git.freedesktop.org/git/xorg/driver/xf86-video-intel
cd xf86-video-intel
./autogen.sh --prefix=$HOME/install
make
make install

To run the new server I usually just cd to $HOME/src/xserver/hw/xfree86 as root and run the Xorg binary there, but first load the DRM modules we compiled above. You typically need to unload the old versions first and then load the ones you compiled (assuming intel hardware):

rmmod i915
rmmod drm
insmod $HOME/src/drm/linux-core/drm.ko
insmod $HOME/src/drm/linux-core/i915.ko

Second, remember to set

export LD_LIBRARY_PATH=$HOME/install/lib
after changing to root so the X server picks up the right libdrm. The X server will use the system xorg.conf from /etc/X11 by default, but that can be changed by passing an option to the X server configure script or passing the -config option to the server.

To actually launch applications under the server I typically just use a lame hack such as

./Xorg && gnome-terminal --display=:0

or more often I just run the X server and applications from a remote login. Before running direct rendering OpenGL applications, you need to the path to the DRI drivers:

export LIBGL_DRIVERS_PATH=$HOME/install/lib/dri

and voila, you can now run OpenGL applications on your very own, hand-built X/DRI/DRM stack. It's not terribly useful for daily use, but I find that it's the best set up for developing and tracking upstream development.

7 comments:

Seppo said...

Nice tutorial! X.org development environment is not the friendliest possible to set up from scratch.

I wonder if it is possible to easily run the whole gnome/KDE desktop from a distro on top of a custom installed X.org? It's easy enough to start gnome-session, but at least on Ubuntu that does not set up everything correctly.

Dan Nicholson said...

Kristian,

The equivalent "autogen.sh" in mesa is `make configure'. This will run aclocal and autoconf (and anything else in the future which might be needed).

Also, if you're setting LD_LIBRARY_PATH, you should pick up the libGL in $HOME/install. In that case, LIBGL_DRIVERS_PATH should not be needed since the correct path is built into libglx and libGL, right? I imagine this is more of a hangover from when it was difficult to set the correct path in mesa.

Seppo,

One way to use a local Xorg is to point GDM at your new server. The files might be different in Ubuntu, but on my system, you can look at the file /usr/share/gdm/defaults.conf to see how things are set in the [servers] section. Then you can add a local setting in /etc/gdm/custom.conf:

[servers]
# set the default server
0=foo
[server-foo]
name=Local server
command=/your/local/Xorg [options]
flexible=true

You'd also want to make sure that you've set LD_LIBRARY_PATH ahead of time or just add the library path to /etc/ld.so.conf.

MacSlow said...

Thanks a lot for this detailed description. This will help me sort all the bits and pieces I got to know about X.org building in my head!

Alex said...

Hmm I'm having no joy once I get to building the xserver stage. It fails on configure step trying to link to the mesa src tree:

=/home/alex/src/xhacking/mesa.git/src/mesa/ is not a dir
symlink-mesa.sh src-dir dst-dir
src-dir: the Mesa source directory
dst-dir: the GL subdirectory of the Xserver modular tree
configure: error: Failed to link Mesa source tree. Please specify a proper path to Mesa sources, or disable GLX.


I've tried several points in the checked out mesa tree. Where exactly is it expecting the config to point to?

Anonymous said...

Alex:

It's in /mesa/src

not /src/mesa

Alex said...

The src dir was my own... sorry for confusion

checking for GL... yes
=/home/alex/src/xhacking/mesa.git/src/ is not a dir
symlink-mesa.sh src-dir dst-dir
src-dir: the Mesa source directory
dst-dir: the GL subdirectory of the Xserver modular tree
configure: error: Failed to link Mesa source tree. Please specify a proper path to Mesa sources, or disable GLX.

07:37 alex@malory/AMD Athlon(tm) 64 Processor 3400+ [xserver.git] >ls /home/alex/src/xhacking/mesa.git/src/
Makefile descrip.mms egl glu glut glw glx mesa

And if I use the top level of the mesa src tree I get the same warning:

checking for GL... yes
=/home/alex/src/xhacking/mesa.git/ is not a dir
symlink-mesa.sh src-dir dst-dir
src-dir: the Mesa source directory
dst-dir: the GL subdirectory of the Xserver modular tree
configure: error: Failed to link Mesa source tree. Please specify a proper path to Mesa sources, or disable GLX.

It just seems the configure script is broken.

Anonymous said...

after configuring drm, mesa, and while going ahead with xserver I am facing this below.. tried many times..

Please help...


make[1]: Leaving directory `/root/xserver/randr'
Making all in render
make[1]: Entering directory `/root/xserver/render'
../doltcompile gcc -DHAVE_CONFIG_H -I. -I../include -DHAVE_DIX_CONFIG_H -Wall -Wpointer-arith -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations -Wnested-externs -fno-strict-aliasing -D_BSD_SOURCE -DHAS_FCHOWN -DHAS_STICKY_DIR_BIT -I/root/install/include -I/usr/include/freetype2 -I/usr/include/pixman-1 -I../include -I../include -I../Xext -I../composite -I../damageext -I../xfixes -I../Xi -I../mi -I../miext/shadow -I../miext/damage -I../render -I../randr -I../fb -g -O2 -MT glyph.lo -MD -MP -MF .deps/glyph.Tpo -c -o glyph.lo glyph.c
glyph.c:33:26: error: openssl/sha.h: No such file or directory
glyph.c: In function ‘HashGlyph’:
glyph.c:217: error: ‘SHA_CTX’ undeclared (first use in this function)
glyph.c:217: error: (Each undeclared identifier is reported only once
glyph.c:217: error: for each function it appears in.)
glyph.c:217: error: expected ‘;’ before ‘ctx’
glyph.c:220: warning: implicit declaration of function ‘SHA1_Init’
glyph.c:220: warning: nested extern declaration of ‘SHA1_Init’
glyph.c:220: error: ‘ctx’ undeclared (first use in this function)
glyph.c:224: warning: implicit declaration of function ‘SHA1_Update’
glyph.c:224: warning: nested extern declaration of ‘SHA1_Update’
glyph.c:232: warning: implicit declaration of function ‘SHA1_Final’
glyph.c:232: warning: nested extern declaration of ‘SHA1_Final’
make[1]: *** [glyph.lo] Error 1
make[1]: Leaving directory `/root/xserver/render'
make: *** [all-recursive] Error 1


Let me know if you need any further details..

Thanks,
Chandra K.