BeagleBone Black - USB network interface

[PLyttle]

Success, at least when the remaining lines of uEnv are added. mine nor reads as follows: (not to confuse other readers)
$this->bbcode_second_pass_code('', 'bootcmd=run findfdt; if test $board_name = A335BNLT; then setenv mmcdev 1; mmc dev ${mmcdev}; if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadbootenv; then run importbootenv;fi;if test -n $uenvcmd; then echo Running uenvcmd ...;run uenvcmd;fi;fi;fi;setenv mmcdev 0; mmc dev ${mmcdev}; if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadbootenv; then run importbootenv;fi;if test -n $uenvcmd; then echo Running uenvcmd ...;run uenvcmd;fi;if run loaduimage; then run loadfdt;run mmcboot;fi;else run nandboot;fi;
mmcroot=/dev/mmcblk0p2 rw
loadfdt=ext4load mmc ${mmcdev}:2 ${fdtaddr} /boot/dtbs/${fdtfile}
loaduimage=if ext4load mmc 0:2 ${loadaddr} /boot/zImage; then setenv mmcdev 0; else setenv mmcdev 1; if test $mmc0 = 1; then setenv mmcroot /dev/mmcblk1p2 rw; fi; ext4load mmc 1:2 ${loadaddr} /boot/zImage; fi
')
But, for it to work it needs to be implemented on the eMMC too. eMMC still gets probed first.
$this->bbcode_second_pass_code('', 'SD/MMC found on device 1
reading uEnv.txt <------eMMC
570 bytes read in 4 ms (138.7 KiB/s)
Importing environment from mmc ...
mmc0 is current device
SD/MMC found on device 0
reading uEnv.txt <------SD-card
870 bytes read in 3 ms (283.2 KiB/s)
Importing environment from mmc ...
3253384 bytes read in 551 ms (5.6 MiB/s)
23801 bytes read in 35 ms (664.1 KiB/s)
Booting from mmc ...
')

Still, no problem as long as you are aware of it.
However, now i'm lost as to where to put my i2c command...

LP

[PLyttle]

found it.

the first line should read:
uenvcmd=i2c mw 0x24 1 0x3e; $uenvcmd

so you get:

uenvcmd=i2c mw 0x24 1 0x3e; $uenvcmd
bootcmd=run findfdt; if test $board_name = A335BNLT; then ....

I hope this syntax works and I don't break the existing uenvcmd this way, but everything seems to work (incliuding the powersetting)
However it should be implemented on only one of the disks. I use eMMC, because it always gets read
if uenvcmd is empty (which I don't know) the line can simply be uenvcmd=i2c mw 0x24 1 0x3e and be the same on both disks.

LP

[kmihelich]

This will only be getting applied to the Black, so it will fall under the first conditional. The regular Bone has no power issues over USB, and given that it is more commonly powered by computer for the serial port, it would be dangerous to allow the power chip to try to rip more then 500ma through a computer's USB port, potentially damaging equipment.

[PLyttle]

I don't think this should be an issue. There are many USB devices that need more than 500 mA and several methods have been used to overcome this, including Y-cables and "dumb" powered USB-hubs.
you cannot get more current than the computer allows. Setting the cut-off of the client higher simply means that the host will limit the power (or not, depending of the implementation).

LP

[kmihelich]

Getting around the USB specification of 500ma per port is one thing. Assuming everyone is getting around it is dangerous and stupid, as is assuming that the device one may have it plugged into has current limiting circuitry. We cannot know these things, and cannot assume them.

[PLyttle]

You are right off course. I'd only hate to see potential users shy away from Arch because of power issues. Once the word is in the street.. (remember dr-dos?)

LP

[kmihelich]

$this->bbcode_second_pass_quote('kmihelich', 'T')his will only be getting applied to the Black, so it will fall under the first conditional.