u-boot-openmoko 1.3.3 (unofficial package) - testers wanted

Andy Green andy at openmoko.com
Fri May 23 08:36:11 CEST 2008

Hash: SHA1

Somebody in the thread at some point said:
| Hi Rasmussen:
| i think the kboot can do that.
| http://kboot.sourceforge.net/
| Peter Rasmussen wrote:
|> Hi  thomasg,
|> I can see that what I have been able to use is exactly what you
|> intended in your wiki description.
|> So yes, I can boot a system residing on the SDHC card, however the
|> kernel is taken from the NAND image, ie. "your" method :-)

The way to solve that is to have a small, eg, 8MB FAT partition first,
containing the kernel, with a second ext2 partition in the rest of the
card containing the rootfs.  U-boot can succeed to parse the FAT
partition and pull out a kernel image file into memory, boot into that,
rootfs is set for the second partition on kernel commandline.

|> And that is why I in a different mail mentioned that I would like to
|> have the SDHC-support in u-boot, to boot completely independent
|> systems on a flash-card.
|> With presently the size of max. 8GB for a micro-SDHC, one card is able
|> to hold several systems, so I think such an option is a very good idea.

SDHC is a disconnected issue, you can do the above on an old non-SDHC
card.  I added SDHC support to the U-boot Glamo SD driver, but I guess
you are talking about GTA01.  Because of the "flat" nature of U-Boot
stuff, ie, there is no "mmc layer", the driver is responsible to issue
his own MMC/SD commands at the driver layer, so that is where SDHC is
implemented.  If someone with GTA01 -- and a debug board ;-) -- wants to
compare the Glamo SD driver in U-Boot and the existing driver, they will
see it won't be a huge job to copy the SDHC support.  The differences to
take care about are that it counts blocks now not bytes, and there is a
different canned sequence of SD commands, but the ones that worked here
are in the Glamo driver already.

|> This is what I have in my previous listing as well, but I would like
|> to emphasize the following, too:
|> "And if u-boot had USB support implemented so that I could upload an
|> image from my desktop Linux straight to the flash-card without having
|> to boot the Neo all the way to a Linux system, that would be really
|> helpful, too."
|> If I could boot up in u-boot and specify what target-partition on the
|> flash-card I want to put a kernel and a rootfs, and then subsequently
|> boot that image, that would be great!

I think being able to quickly have write access to the SD Card is good,
but I don't think U-Boot has to be or should be part of that picture.
If you change init=/bin/sh and boot again, here you are at a Linux
prompt a few seconds after Linux begins boot... boot to a script instead
like "/etc/startup" that sets up ifconfig and so on and you are
network-capable over the USB in a few seconds after Linux begins boot.

U-Boot isn't the future.

- -Andy
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