#BEAGLEBONE BLACK DRIVER INSTALL FAILED SERIAL#
Just plug it to the J1 connector and open a serial terminal of your choice. To see the actual boot process a RS232 cable like the TTL-232R-3V3 from FTDI is very handy. įinally we can now boot from our microSD card. The details are depending on your configuration :). To instruct U-Boot to get the Linux Kernel and device tree via TFTP. To configure U-Boot we create a file uEnv.txt on the boot partition and fill it, e.g. We should get a MLO and u-boot.bin file in the current directory and can copy those onto the boot partition of microSD card. Now we clone the git repository, create a default configuration and cross compile it for the BeagleBone Black by git clone git:///u-boot.git & cd u-bootĪRCH=arm CROSS_COMPILE=arm-linux-gnueabi- make On Ubuntu this can be installed relatively easy by sudo apt-get install gcc-arm-linux-gnueabihf As we need to cross compile this for the BeagleBone Black we need a suitable compiler. Now you can mount the boot partition manually or replug the microSD card as most systems will mount it then automatically. Writing superblocks and filesystem accounting information: done To zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1 If you created or changed a DOS partition, /dev/foo7, say, then use dd(1) Successfully wrote the new partition table Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0ĭevice Boot Start End #cyls #blocks Id System dev/sdb: unrecognized partition table type Sfdisk: ERROR: sector 0 does not have an msdos signature ĭisk /dev/sdb: 1936 cylinders, 255 heads, 63 sectors/track Primary FAT23 partition of 72261 blocks in size and a Linux ext4 partition of 15478627 blocks in size: 1024+0 records inġ048576 bytes (1.0 MB) copied, 0.447124 s, 2.3 MB/sĭisk /dev/sdb doesn't contain a valid partition tableĬhecking that no-one is using this disk right now. Download, make it executable and run it by wget īe sure to have /dev/sdb pointing to your microSD card and not anything else! In the output of the script you can see the partition table it created and in our case it was a Instead of calculating the exact partitions sizes needed as explained by the MMC boot format wiki page we use a script which does everything for use. The content of the SD card fill be deleted during this procedure. Our microSD card is connected to /dev/sdb as has a size of 16 GB. The following steps were all done on a (virtual) Ubuntu Linux system. Now as we have the theoretical background, let's try it our self.
U-Boot itself will then look for a file named uEnv.txt for further configuration and then act upon it. U-Boot provides this MLO file as a second-stage boot-loader which then loads the actual U-Boot which has to be provided as a file named u-boot.bin in the same directory. U-Boot is a very versatile boot loader which can be used on the BeagleBone Black. If the AM335x processor finds a valid formatted MMC it searchings for a file named MLO on the first partition and if it is found it boots from that file. The onboard eMMC or an external microSD card have to be formatted in a special way for the AM335x processor to find its boot file, which is described very good on the MMC boot format wiki page at TI. If S2 is pressed during power-up the boot sequence is changed toĪs there is usually nothing bootable found on SPI0 it will boot from the microSD card. Usually it will find something in the onboard eMMC and boot from there. In default mode (S2 not pressed) it tries to boot from The BeagleBone Black provides by alternative boot sequences which are selectable by the boot switch (S2). The AM335x processor on the BeagleBone Black has many configurable options where it can boot from which are all documented in Chapter 26 of the AM335x ARM® Cortex™-A8 Microprocessors Technical Reference Manual. As we later want to change the Linux Kernel itself we need to know how it is started by the BeagleBone. Understanding the boot up mechanism of the BeagleBone Black is important to be able to modify it.
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