Yes, I essentially use variations of the following list of commands for rebuilding u-boot:
bitbake -c clean u-boot-imx
bitbake -v -D -f -c package u-boot-imx ###errors occur here
bitbake -v -D -f -c deploy u-boot-imx
bitbake -v _D -f -c rootfs humboldt-image
NOTE: since my previous post I have determined that the following #defines need to be in the board header file (mx6sabresd.h) and not in the defconfig file:
#define CONFIG_SPL_BUILD=y
#define CONFIG_SPL_OS_BUILD=y
#define CONFIG_CMD_SPL=y
I can build v2015_04 u-boot with SPL using the toolchain but I still can not direct bitbake recipes to build SPL.
I did find that in the poky u-boot.inc recipe include file, there is no script to support the compile of SPL - there is only script to install and deploy SPL.
Rich