Currently when building nightly-fsl-arm master on autobuilder.yoctoproject.org we get a symlink from core-image-x11-imx28evk.uboot.mxsboot-sdcard to a file named something like core-image-x11-imx28evk-20130208004213.rootfs.uboot.mxsboot-sdcard. The file it is pointing at does not exist. Also u-boot-imx28evk.mxsboot-sdcard is set to mode 0600. All other files in all the machines directories are set to 0644 the default for our umask. This prevents u-boot-imx28evk.mxsboot-sdcard from being served at http://autobuilder.yoctoproject.org/pub/nightly/20130207-2/machines/imx28evk/u-boot-imx28evk.mxsboot-sdcard for example.
http://git.yoctoproject.org/cgit/cgit.cgi/meta-fsl-arm/commit/?id=c64d5870feb590adc18789706840652d0d4f3d37
Replicated a core-image-x11 with meta-fsl-arm layer and imx28evk MACHINE. The output in build/tmp/deploy/images had no invalid links. Also: -rwxr-xr-x 1 lserban lserban 309336 Apr 17 16:42 u-boot-imx53qsb-v2013.04-r0.imx Verified in master:595e92c76700306f9ff8fcf1557eb7ade1f3e907