Dear all, I have some problems trying to understand how the boot procedure is in the Beaglebone Black. I saw several posts around but it is quite hard for me to fully understand how it works. So, sorry if I am repeating something that most of you already know. What I've understood so far (I hope...) is: 1) if I just power my BBB, the boot procedure is based on the flash placed on the BBB. It means that the ROM Bootloader of the AM335xx loads the MLO from the flash, the u-boot.img from the flash and then "all the rest" starts. 2) if I power my BBB and I push the Boot-button, the ROM Bootloader of the AM335xx loads the MLO and the u-boot.img and "all the rest" from the SD card. The AM335xx does not talk at all with the flash during all the boot procedure. 3) if I try to modify the uEnv.txt in the SD card in such a way to force the OS to be loaded form the SD card, wich means
mmc dev 1 mmc rstn 1 gpio set 52 optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN,BB-BONE-EMMC-2G etc..etc and I do not push the boot button, the AM335xx loads the MLO and the u-boot.img from the flash and "only after that" it will loads the uEnv.txt file from the SD card. It means that the bootloader will search a MLO and u-boot.img in the flash -> they will talk for a while and after that the AM335xx will loads the uEnv.txt from the SD. Now, I would like to have the point number two without to push the boot button: I do not want the AM335xx to talk with the flash at all and I am not pretty sure it is possible. In my opinion there are two ways: the former is to set the resistor on the BBB in such a way to have the same configuration as the boot-button pressed (hardware way). The latter is to erase completely the flash in such a way to have no MLO and u-boot.img in it. However, the second way could not work because the AM335xx will talk with the flash trying to find MLO and the u-boot.img, while I do not want them to talk each other. Is it all correct? Thanks a lot. Alberto -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
