I've been trying to implement vboot from SPI flash on the BeagleBone Black with only limited success. I'm working with u-boot 2016.07 and using the instructions in beaglebone_vboot.txt (in doc directory).
So far: I've had no problem booting regular u-boot from SPI flash. I build with am335x_boneblack_defconfig with minor modifications: added SPI_BOOT to the list of items on CONFIG_SYS_EXTRA_OPTIONS and added CONFIG_SPI_FLASH_STMICRO=y to enable support for my SPI flash chip (M25P16). The I use the following command sequence from the u-boot command line to program the flash:
sf probe 0 sf erase 0 +80000 mmc rescan fatload mmc 0 ${loadaddr} MLO.byteswap sf write ${loadaddr} 0 ${filesize} fatload mmc 0 ${loadaddr} u-boot.img sf write ${loadaddr} 0x20000 ${filesize}
And this works nicely.
I also have had success with vboot enabled u-boot using the beaglebone_vboot.txt instructions and booting from SD card.
*BUT*
when I copy MLO(.byteswap) and u-boot.img that works successfully on SD card to SPI flash it fails to get past the Second Phase Loader:
U-Boot SPL 2016.07 (Aug 10 2016 - 16:06:39) Trying to boot from SPI
U-Boot SPL 2016.07 (Aug 10 2016 - 16:06:39) Trying to boot from SPI
... etc for ever
On an oscilloscope I can see what I'm sure is the SPL trying to loading u-boot.img on the SPI bus. But it never gets as far as executing it.
So in summary, I've got SPI boot working and vboot working but I cannot seem to combine both.
Any ideas what I'm doing wrong?
Thanks,