booting beagleplay

Hi all,

I have a strange behavior or maybe not strange but trying to understand.
On SDCard I have 2 partitions boot and rootfs. Rootfs is empty but boot has valid binaries.
mmc flash is erased
mmc dev 0 1
mmc erase 0 0x2400
Now pressing the user button and reset board start to boot but for my surprise it also loads somehow the linux image even it is not exiting on the SDCard. How is it possible?
When pressing reset (without user button) board doesnt boot and this is fine it should be like that.

Regards

Ok this seams normal and explained here Trying to understand the default boot process (eMMc / uSD) on BeaglePlay