Modify code git source
From ESS-WIKI
# you may modify git source of distro ubuntu/rcw/uboot/kernel
vim flexbuild_lsdk2012/configs/build_lsdk.cfg
# choose one of the 3 ways to fetch/update repo in various cases
UPDATE_REPO_PER_BRANCH=n
UPDATE_REPO_PER_COMMIT=n
UPDATE_REPO_PER_TAG=y
# set default distro Ubuntu/Debian codename
distro_codename=bionic
# firmware git repositories
rcw_repo_url=https://source.codeaurora.org/external/qoriq/qoriq-components/rcw.git
rcw_repo_tag=LSDK-20.12
uboot_repo_url=https://source.codeaurora.org/external/qoriq/qoriq-components/u-boot.git
uboot_repo_tag=LSDK-20.12
uboot_imx_repo_url=https://source.codeaurora.org/external/imx/uboot-imx
uboot_imx_repo_tag=rel_imx_4.9.123_2.3.0_8mm_ga
# kernel and linux modules git repositories
linux_repo_url=https://source.codeaurora.org/external/qoriq/qoriq-components/linux.git
linux_repo_branch=linux-5.4
linux_repo_tag=LSDK-20.12-V5.4