Can't get Arch on eMMC of BeagleBone Black [SOLVED]

[tdio]

I'm following these instructions: http://archlinuxarm.org/platforms/armv7/beaglebone-black
I can boot the arch SD Card, I can replace the bootloader, but when I try to unpack arch onto the root partition it will run for a few seconds then the board will power off. I've tried watch dmesg before this happens but I haven't seen anything.

In review, the last failing commands are something like:
$this->bbcode_second_pass_code('', '
$ mkfs.ext4 /dev/mmcblk1p2
$ mkdir root
$ mount /dev/mmcblk1p2 root
$ tar -xf ArchLinuxARM-am33x-latest.tar.gz -C root
')

Runs for a few seconds then loses power, I thought it may be a power issue so I tried 2 different USB power wallwarts and a laptop usb power with the same results. Thinking that the unzipping could cause a cpu spike and increase need for power, I forkbombed it and it never lost power (I lost SSH eventually but it did not lose power).

Any suggestions? I'm starting to wonder if I have a defective board.

*update:
I re-downloaded the archlinux tarball (for good measure) unzipped it to a directory on the sd card and ran cp to copy the extracted files to the eMMC, this beagleboard stayed powered on significantly longer but still died after about 45 seconds. Once I got the board booted back up I ran cp again with the noclobber option and got the files to the eMMC but I suspect there might be a corrupted half-copied file on the filesystem that will comeback to haunt me later.

[Geoff]

You need to provide 5V power through the barrel connector. The BeagleBoard will not allow itself to draw enough current through the USB connector, no matter how much is available.

[tdio]

Thanks,
I've found some other threads here and discovered that the arch arm kernel has CPU scaling set up for performance instead of power savings, so that makes sense. I'm trying to compile the kernel with CPU scaling set to conservative, then if that goes well ondemand.

[kmihelich]

The latest bootloader tarball available on the installation page has a fix in the uEnv.txt for allowing >500mA through the mini-USB port.

You can also add this to your current uEnv.txt by adding the following command to uenvcmd:
$this->bbcode_second_pass_code('', 'i2c mw 0x24 1 0x3e')

To make it look like this:
$this->bbcode_second_pass_code('', 'uenvcmd=run findfdt; if test $board_name = A335BNLT; then i2c mw 0x24 1 0x3e; setenv mmcde.....')

However, because we know it can draw over 500mA, we recommend using a USB charger that can supply more than this as opposed to a port on a computer.