Building for BeagleBone
Setting up cross-compile environment is the first and necessary step.
The easier way is install the default compiler provided by your distribution.
Ubuntu : gcc-arm-linux-gnueabi
Arch Linux : arm-linux-gnueabi-gcc
Debian : ??
Fedora : ??
Linux Mint : ??
- Tip: Do a alias in your environment, where N is the number of processors cores plus one:
$ alias armmake='make -jN ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- '
You can use the mainline u-boot for beaglebone.
$ git clone git://git.denx.de/u-boot.git
$ armmake distclean
Configure for BeagleBone:
$ armmake am335x_evm_config
Test your new U-Boot
You need a microSd card with 2Gb or more. In order to make U-Boot work you will need to create the first partion as FAT32 LBA, bootable, with something like 64 Megabytes.
This command wipes everything from your sdcard and creates that partition.
$ echo -e "o\nn\np\n1\n\n+64M\na\n1\nt\nc\nw\n" | sudo fdisk /dev/MYDISK ; sudo fdisk /dev/MYDISK -l
This comand should print something like:
Disk /dev/sdb: 7948 MB, 7948206080 bytes 16 heads, 4 sectors/track, 242560 cylinders, total 15523840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x1c524301 Device Boot Start End Blocks Id System /dev/sdb1 * 2048 133119 65536 c W95 FAT32 (LBA)
The U-Boot compilation generated two files, MLO and uboot.img. Mount the partition that you just created and copy FIRST the MLO file to partition. Then copy the u-boot.img.
$ sudo mount /dev/MYDISK /mnt $ sudo cp MLO /mnt $ sudo cp u-boot.img $ sudo sync $ sudo umount /mnt
Now with that sdcard in BeagleBone the output from serial should be:
U-Boot SPL 2014.07-rc3-00136-gba9b42c (Jun 25 2014 - 14:36:07) reading u-boot.img reading u-boot.img U-Boot 2014.07-rc3-00136-gba9b42c (Jun 25 2014 - 14:36:07) I2C: ready DRAM: 512 MiB NAND: 0 MiB MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1 *** Warning - readenv() failed, using default environment Net: <ethaddr> not set. Validating first E-fuse MAC cpsw, usb_ether Hit any key to stop autoboot: 0 switch to partitions #0, OK mmc0 is current device SD/MMC found on device 0 reading uEnv.txt 9 bytes read in 4 ms (2 KiB/s) Loaded environment from uEnv.txt Importing environment from mmc ... ** Invalid partition 2 ** switch to partitions #0, OK mmc1(part 0) is current device SD/MMC found on device 1 reading uEnv.txt 26 bytes read in 4 ms (5.9 KiB/s) Loaded environment from uEnv.txt Importing environment from mmc ... ** File not found /zImage ** Booting from nand ... no devices available no devices available Bad Linux ARM zImage magic! U-Boot#
There are two problems in this output. First, you don't have a uEnv.txt, which configure the U-Boot and secondly you don't have a linux image.