Topic: USB Boot

Other than boot from uSD, USB recovery boot could be tremendous useful for kernel developing. But I see GL850G still stand in the way, why? Why OTG still not DNP? Who need a USB HUB on board when an external one is easily available?


Re: USB Boot

As I understand it, it's an either/or: Either you get USB host mode, which will give you wifi and an external USB port (which will let you connect Ethernet, or a keyboard, or...), or you have OTG, which will let you connect the chumby to a PC.  We figured it was more useful to go for the expandability route, rather than relying on various USB gadget modules.

For kernel developing, it's usually not too difficult to pop the SD card into a PC and dd over a new kernel.  You ought to be able to get a new kernel on by running:

dd if=arch/arm/boot/zImage of=/dev/sdc1 seek=3072

Re: USB Boot

For Chumby with built-in USB wifi, it is desirable to have HUB chip on board. But, hey, this time is for hacker board, and hackers all have different, if not all wild ideas. So I assume this board needs to be generic and more like a core block with SoC and memory only, and have as much IO exposed. It is almost there, please just remove GL850G and populate OTG block, I will be thrilled.

As for kernel, I mean not only matured one like Linux, but also experimental one, such as the Inferno port I attempted months ago. The pain of swapping uSD dozen times a day was simply too much.


4 (edited by acamilo 2010-11-01 16:16:41)

Re: USB Boot

If you're comfortable with SMT rework then you try what i did pull the hub and USB0 off. Move L504 into L508's spot and solder in 100k ohms for R511 and R512. And finally solder in a usb mini-b jack onto the pads under USB0.

I left R506 disconnected so  wouldn't have to pull any more power related stuff off. (i left it plugged into the power brick)


chumby-:/lib/modules/2.6.28-chumby/kernel/drivers/usb/gadget # insmod arcotg_udc
[ 2433.170000] ARC USBOTG Device Controller driver (1 August 2005)
[ 2433.180000] fsl-usb2-udc fsl-usb2-udc: does not remap its address space
chumby-:/lib/modules/2.6.28-chumby/kernel/drivers/usb/gadget # insmod g_ether.ko

[ 2445.200000] g_ether gadget: using random self ethernet address
[ 2445.200000] g_ether gadget: using random host ethernet address
[ 2445.230000] usb0: MAC 2a:4b:6c:42:d1:ab
[ 2445.230000] usb0: HOST MAC e6:16:34:5e:6c:ab
[ 2445.250000] g_ether gadget: Ethernet Gadget, version: Memorial Day 2008
[ 2445.260000] g_ether gadget: g_ether ready
[ 2445.260000] fsl-usb2-udc: bind to driver g_ether

The device came up as a RNDIS Ethernet device on my PC.

Oh, i also RMMODED an EHCI module and another one i forgot about.