Hi Adrian,
Thank you for the help. With those commands I am able to build u-boot with spl. However, after writing the new binary image to the SD card, I am unable to see any console prompt from u-boot.
These are the steps I have done so far:
Edit meta-fsl-arm/conf/machine/ls1021atwr.conf to use UBOOT_CONFIG ??= "sdcard"
$ cd build_ls1021atwr_release/
$ bitbake -c cleansstate u-boot
$ bitbake -c patch u-boot
$ bitbake -c compile -f u-boot
$ cd tmp/work/ls1021atwr-fsl-linux-gnueabi/u-boot-ls1/2014.07-r0/git/
$ sudo dd if=u-boot.bin of=/dev/sdN bs=512 seek=8 && sync
$ umount /dev/sdN1
The DIP switch SW2 is set to 00101111 and SW3 is 01100001. J19/J20 are both shorted to 2:3.
Doing a hexdump of u-boot.bin shows the eSDHC preable word AA 55 AA 55 at address 0x1000 (LSA1021A Reference Manual rev E pgs 252 & 266).
This discussion (https://community.freescale.com/thread/371771) has attached a working u-boot_prebuilt.bin. After extracting and running through the same steps as above, I was able to get a u-boot prompt. So that confirms that my switches are in the correct position and u-boot is getting written to the card. I suspect that my u-boot.bin is still not being built correctly.
Are there any other steps required to make u-boot boot on SD?
Thank you,
Josh