During discussions on IRC about the future boot process using u-boot, we came to the conclusion that we need to repartition the device first. By default, the AC100 using a proprietary partitioning scheme which cannot (or shouldn't?) be supported by mainline kernels. So before introducing a new bootloader, we need to install a new partition table (preferable gpt format) without (also preferable) loosing any data.

A few words to the EMMC (internal storage) layout. There are two different EMMCs build into the various AC100 models. One from SanDisk and one from Toshiba. I mention this because they use different size of secure partitions. These partitions which cannot be access by uboot at the time of writing this (may be possible in the future though). On the other hand, the kernel can do. Because we plan to put our bootloader into these partitions, we need to boot a kernel with an initramfs filesystem first to be able to flash the bootloader. Some program needs to detect the EMMC type and flash the bootloader to the “right” place. This “flashing” process is also decribed on this page.