Bas Laarhoven has verified a fix for turning your BBB into a BBW (or perhaps that's BeagleBone Grey?). Details are in the Google groups thread (scroll to the bottom for the fix), and summarized here:
- Find the mmc2 section in the BeagleBone Black device tree and change
status = "okay"
status = "disabled"
- Add "gpio set 52" to your uboot configuration to put the eMMC chip in reset at boot time
- Enable the eMMC hardware reset pin. This is a one-time configuration (it survives power cycles and cannot be changed once enabled) you can perform with either uboot or the mmc-utils program.
If you want to completely mimic the original BeagleBone boot behavior, you need to swap four resistors on the 'Black, or otherwise set the proper boot mode via the LCD_DATA pins on P8. Details of what needs to be setup:
- SYS_BOOT0 = 1: Move R95 to R70 or pull down LCD_DATA0 during reset
- SYS_BOOT1 = 1: Move R94 to R69 or pull down LCD_DATA1 during reset
- SYS_BOOT2 = 1: No change needed, leave R68 alone
- SYS_BOOT3 = 0: Move R67 to R92 or pull up LCD_DATA3 during reset
Oh, and if you're worried about wasting money on the on-board eMMC card, don't be. Even if you disable the eMMC card at boot time via the resistor mods it's not gone. You can still load a device tree overlay and start talking to it (assuming you don't have a conflicting cape plugged in). If you are leaving 'Black booting from the on-chip eMMC, just tweak uEnv.txt and pop out your SD card and you're back to full Black, booting from the on-board flash.