--------------------------------------------------------------------
step2. firmware-imx is OK
I had try https://community.nxp.com/docs/DOC-346089 : git.freescale.com.imx.imx-firmware.git.7z.zip
and copy it to downloads/git2/ && bitbake firmware-imx , It's very good!
--------------------------------------------------------------------
step3. bitbake fsl-image-qt5-validation-imx , failed
WARNING: linux-imx-4.1.15-r0 do_fetch: Failed to fetch URL git://git.freescale.com/imx/linux-imx.git;protocol=git;branch=imx_4.1.15_2.0.0_ga, attempting MIRRORS if available
ERROR: linux-imx-4.1.15-r0 do_fetch: Fetcher failure: Fetch command failed with exit code 128, output:
Cloning into bare repository '/home/linux/fsl-release-bsp/downloads//git2/git.freescale.com.imx.linux-imx.git'...
fatal: unable to connect to git.freescale.com:
git.freescale.com: No address associated with hostname
ERROR: linux-imx-4.1.15-r0 do_fetch: Function failed: Fetcher failure for URL: 'git://git.freescale.com/imx/linux-imx.git;protocol=git;branch=imx_4.1.15_2.0.0_ga'. Unable to fetch URL from any source.
ERROR: Logfile of failure stored in: /home/linux/fsl-release-bsp/build_x11_imx6ulevk/tmp/work/imx6ulevk-poky-linux-gnueabi/linux-imx/4.1.15-r0/temp/log.do_fetch.5489
ERROR: Task 50 (/home/linux/fsl-release-bsp/sources/meta-fsl-bsp-release/imx/meta-bsp/recipes-kernel/linux/linux-imx_4.1.15.bb, do_fetch) failed with exit code '1'
WARNING: cpuburn-neon-20140626-r0 do_fetch: Failed to fetch URL https://raw.githubusercontent.com/ssvb/cpuburn-arm/dd5c5ba58d2b0b23cfab4a286f9d3f5510000f20/cpuburn-..., attempting MIRRORS if available
ERROR: cpuburn-neon-20140626-r0 do_fetch: Fetcher failure: Fetch command failed with exit code 4, no output
ERROR: cpuburn-neon-20140626-r0 do_fetch: Function failed: Fetcher failure for URL: 'https://raw.githubusercontent.com/ssvb/cpuburn-arm/dd5c5ba58d2b0b23cfab4a286f9d3f5510000f20/cpuburn-a8.S;name=ssvb'. Unable to fetch URL from any source.
ERROR: Logfile of failure stored in: /home/linux/fsl-release-bsp/build_x11_imx6ulevk/tmp/work/cortexa7hf-neon-poky-linux-gnueabi/cpuburn-neon/20140626-r0/temp/log.do_fetch.5499
ERROR: Task 2748 (/home/linux/fsl-release-bsp/sources/meta-openembedded/meta-oe/recipes-benchmark/cpuburn/cpuburn-neon_20140626.bb, do_fetch) failed with exit code '1'
WARNING: u-boot-imx-2016.03-r0 do_fetch: Failed to fetch URL git://git.freescale.com/imx/uboot-imx.git;protocol=git;branch=imx_v2016.03_4.1.15_2.0.0_ga, attempting MIRRORS if available
ERROR: u-boot-imx-2016.03-r0 do_fetch: Fetcher failure: Fetch command failed with exit code 128, output:
Cloning into bare repository '/home/linux/fsl-release-bsp/downloads//git2/git.freescale.com.imx.uboot-imx.git'...
fatal: unable to connect to git.freescale.com:
git.freescale.com: No address associated with hostname
ERROR: u-boot-imx-2016.03-r0 do_fetch: Function failed: Fetcher failure for URL: 'git://git.freescale.com/imx/uboot-imx.git;protocol=git;branch=imx_v2016.03_4.1.15_2.0.0_ga'. Unable to fetch URL from any source.
ERROR: Logfile of failure stored in: /home/linux/fsl-release-bsp/build_x11_imx6ulevk/tmp/work/imx6ulevk-poky-linux-gnueabi/u-boot-imx/2016.03-r0/temp/log.do_fetch.5506
ERROR: Task 207 (/home/linux/fsl-release-bsp/sources/meta-fsl-bsp-release/imx/meta-bsp/recipes-bsp/u-boot/u-boot-imx_2016.03.bb, do_fetch) failed with exit code '1'

------------------------------------------------------------------------------------------
step4. Just take uboot as an example , failed
--->
I modify it like this :
linux@ubuntu:~/fsl-release-bsp/sources$ vi meta-fsl-bsp-release/imx/meta-bsp/recipes-bsp/u-boot/u-boot-imx_2016.03.bb
...
11 #SRCBRANCH = "imx_v2016.03_4.1.15_2.0.0_ga"
12 #UBOOT_SRC ?= "git://git.freescale.com/imx/uboot-imx.git;protocol=git"
13 #SRC_URI = "${UBOOT_SRC};branch=${SRCBRANCH}"
14 #SRCREV = "0ec2a019117bb2d59b9672a145b4684313d92782"
15 SRCBRANCH = "nxp/imx_v2016.03_4.1.15_2.0.0_ga"
16 UBOOT_SRC ?= "https://source.codeaurora.org/external/imx/uboot-imx;protocol=https"
17 SRC_URI = "${UBOOT_SRC};branch=${SRCBRANCH}"
18 SRCREV = "0ec2a019117bb2d59b9672a145b4684313d92782"
...
--->
linux@ubuntu:~/fsl-release-bsp/build_x11_imx6ulevk$ bitbake fsl-image-qt5-validation-imx -k
...
ERROR: u-boot-imx-2016.03-r0 do_fetch: No checksum specified for /home/linux/fsl-release-bsp/downloads/uboot-imx, please add at least one to the recipe:
SRC_URI[md5sum] = "1313a67e12cb877b7682b13d970323fa"
SRC_URI[sha256sum] = "60f1f6f5eb0801f44b99e3a1c08ca4e59fd91285f4f05990345c521847576111"
ERROR: u-boot-imx-2016.03-r0 do_fetch: Function failed: Fetcher failure for URL: 'https://source.codeaurora.org/external/imx/uboot-imx;protocol=https;branch=nxp/imx_v2016.03_4.1.15_2.0.0_ga'. Missing SRC_URI checksum
ERROR: Logfile of failure stored in: /home/linux/fsl-release-bsp/build_x11_imx6ulevk/tmp/work/imx6ulevk-poky-linux-gnueabi/u-boot-imx/2016.03-r0/temp/log.do_fetch.5631
ERROR: Task 207 (/home/linux/fsl-release-bsp/sources/meta-fsl-bsp-release/imx/meta-bsp/recipes-bsp/u-boot/u-boot-imx_2016.03.bb, do_fetch) failed with exit code '1'
...

--------------------------------------------------------
Missing SRC_URI checksum ? SRCREV ?