Yocto e-SDK contains minimal shared
state (sstate) cache.
Xilinx®
hosts the full
petalinux-image sstate cache at http://petalinux.xilinx.com/sswreleases/rel-v2020/.
During petalinux-build, BitBake searches
for the sstate cache in http://petalinux.xilinx.com/sswreleases/rel-v2020/. If it fails to find the sstate cache, BitBake will build it from
scratch. sstate is signature locked.
For a .bbappend file which you create
for any root file system component, you must add SIGGEN_UNLOCKED_RECIPES += "<recipe-name>" or
SIGGEN_UNLOCKED_RECIPES += "u-boot-xlnx" in <plnx-proj-root>/project-spec/meta_user/conf/petalinuxbsp.conf.