(gdb) bt full
#0  i830_allocate_aperture (pScrn=0x7fe210, name=0x2aaf2f0cf4fb "secondary front buffer", size=<value optimized out>,
    alignment=65536, flags=0) at i830_memory.c:429
        mem = (i830_memory *) 0x8131b0
        scan = (i830_memory *) 0x80fe30
#1  0x00002aaf2f0b11c5 in i830_allocate_memory (pScrn=0x80d300, name=0x2aaf2f0cf518 "ary ", size=8453680, alignment=0,
    flags=-16843009) at i830_memory.c:529
        mem = <value optimized out>
#2  0x00002aaf2f0b2370 in i830_allocate_framebuffer (pScrn=0x7fe210, pI830=0x80fe30, FbMemBox=0x8008a8, secondary=1, flags=0)
    at i830_memory.c:922
        pitch = 2560
        cacheLines = <value optimized out>
        maxCacheLines = <value optimized out>
        size = 3276800
        fb_height = <value optimized out>
        name = 0x2aaf2f0cf4fb "secondary front buffer"
        front_buffer = (i830_memory *) 0x1000
#3  0x00002aaf2f0b2690 in i830_allocate_2d_memory (pScrn=0x7fd9c0) at i830_memory.c:1095
        pI830 = (I830Ptr) 0x800870
#4  0x00002aaf2f0ae302 in I830ScreenInit (scrnIndex=0, pScreen=0x85b590, argc=<value optimized out>,
    argv=<value optimized out>) at i830_driver.c:2444
        savedDisplayWidth = 1280
        tiled = 1
        pScrn = (ScrnInfoPtr) 0x7fd9c0
        hwp = <value optimized out>
        pI830 = (I830Ptr) 0x800870
        visual = <value optimized out>
        pI8301 = (I830Ptr) 0x0
        sys_mem = <value optimized out>
        i = 0
        savedMMSize = 32768
        pitches = {1024, 2048, 4096, 8192, 0}
#5  0x00000000004394be in AddScreen (pfnInit=0x2aaf2f0add97 <I830ScreenInit>, argc=3, argv=0x7fff7e3b9fc8) at main.c:773
        i = 0
        scanlinepad = <value optimized out>
        format = 0
        depth = <value optimized out>
        bitsPerPixel = 32
        k = <value optimized out>
        pScreen = (ScreenPtr) 0x2aaf2f0cf518
#6  0x0000000000466ee1 in InitOutput (pScreenInfo=0x7dc360, argc=3, argv=0x7fff7e3b9fc8) at xf86Init.c:924
        i = <value optimized out>
        j = <value optimized out>
        k = <value optimized out>
        scr_index = 2
        modulelist = <value optimized out>
        optionlist = (pointer *) 0x7f75f0
        layout = <value optimized out>
---Type <return> to continue, or q <return> to quit---
        screenpix24 = <value optimized out>
        pix24 = Pix24Use32
        pix24From = X_DEFAULT
        autoconfig = <value optimized out>
        generation = 1
#7  0x0000000000439cb5 in main (argc=3, argv=0x7fff7e3b9fc8, envp=0x7fff7e3b9fe8) at main.c:370
        i = 0
        error = 0
        xauthfile = <value optimized out>
        alwaysCheckForInput = {0, 1}