root@localhost:~# gdb /usr/bin/Xorg $(pidof Xorg)
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Reading symbols from /usr/bin/Xorg...Reading symbols from /usr/lib/debug//usr/bin/Xorg...done.
done.
(gdb) r
Starting program: /usr/bin/Xorg
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/arm-linux-gnueabihf/libthread_db.so.1".

X.Org X Server 1.15.1
Release Date: 2014-04-13
X Protocol Version 11, Revision 0
Build Operating System: Linux 3.2.0-67-highbank armv7l Ubuntu
Current Operating System: Linux localhost.localdomain 3.14.14+ #14 SMP Tue Mar 24 11:46:32 EDT 2015 armv7l
Kernel command line: root=/dev/mmcblk0p2 ro max_loop=16 rootwait consoleblank=0
Build Date: 12 February 2015  02:55:07PM
xorg-server 2:1.15.1-0ubuntu2.7 (For technical support please see http://www.ubuntu.com/support)
Current version of pixman: 0.30.2
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan  1 00:29:14 1970
(==) Using system config directory "/usr/share/X11/xorg.conf.d"

Program received signal SIGSEGV, Segmentation fault.
__GI_strncmp (s1=<optimized out>, s1@entry=0x0, s2=s2@entry=0x54bd6544 "pci:", n=n@entry=4) at strncmp.c:42
42      strncmp.c: No such file or directory.
(gdb) bt f
#0  __GI_strncmp (s1=<optimized out>, s1@entry=0x0, s2=s2@entry=0x54bd6544 "pci:", n=n@entry=4) at strncmp.c:42
        n4 = 0
        c1 = <optimized out>
        c2 = <optimized out>
#1  0x54b1f786 in xf86platformProbe () at ../../../../hw/xfree86/common/xf86platformBus.c:232
        i = 0
        pci = <optimized out>
#2  0x54b01d66 in xf86BusProbe () at ../../../../hw/xfree86/common/xf86Bus.c:203
No locals.
#3  0x54b0bd60 in InitOutput (pScreenInfo=pScreenInfo@entry=0x54c0f608 <screenInfo>, argc=argc@entry=1, argv=argv@entry=0x7efff834) at ../../../../hw/xfree86/common/xf86Init.c:470
        i = <optimized out>
        j = <optimized out>
        k = <optimized out>
        scr_index = <optimized out>
        modulelist = <optimized out>
        optionlist = 0x54c0390c <serverGeneration>
        screenpix24 = <optimized out>
        pix24 = <optimized out>
        pix24From = X_DEFAULT
        pix24Fail = 0
        autoconfig = 0
        sigio_blocked = 0
        want_hw_access = 0
        configured_device = <optimized out>
#4  0x54ae2548 in dix_main (argc=1, argv=0x7efff834, envp=<optimized out>) at ../../dix/main.c:200
        i = <optimized out>
        alwaysCheckForInput = {0, 1}
#5  0x76cde632 in __libc_start_main (main=0x54ad4885 <main>, argc=1, argv=0x7efff834, init=<optimized out>, fini=0x54bcd121 <__libc_csu_fini>, rtld_fini=0x76fea4c5 <_dl_fini>,
    stack_end=0x7efff834) at libc-start.c:287
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, 0, 1994039296, 0, 0, 0, 1421852672, 0, -181808996, -48512903, 0 <repeats 21 times>, 1996487440, 0, 1996487000, -1, 0, 1993158184,
                1996458080, 0, 0, 4096, 255, 0, 0, 0, 0, 0, 0, 1996238848, 1991475200, 1420468224, 1384596, 1420529872, 0, 0, 1421852672, 0, 1996397007, 1991615888, 1, 1, 0, -4,
                1993158184}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x76fee19c <_dl_runtime_resolve+24>}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#6  0x54ad48bc in _start ()
No symbol table info available.
(gdb)