The Bootloader for Beaglebone that comes with Starterware is able to load a "app" file from external SD-Card (MMC0 lines of CPU). Since BeagleBone Black there exists a second storage eMMC (which is connected to MMC1 lines).
Now I tried to modify the Bootloder sources to let MLO read from eMMC but failed miserably. That's what I have changed:
- changed MMC0-base-address and MMC0-register and constant names to MMC1 in all relevant sources (like SOC_MMCHS_0_REGS to SOC_MMCHS_1_REGS)
- modified HSMMCSDImageCopy() to load file from "1:\app" to get drive 1
- fixed the assignment bug in HSMMCSDFsMount() to use fat_devices[driveNum] instead of fat_devices[0]
- mount drive 1 prior to accessing FAT-FS
- modified functions in fat_mmcsd.c to allow access of drive 1 and 0 (instead of 0 only)
Nevertheless eMMC - which of course contains a FAT-FS partition - is not accessible. Any ideas what could be missing here?