Re: [Gumstix-users] RAM to MMC

[Craig H. <cr...@gu...>]

On Aug 11, 2006, at 12:00 PM, Sean Wheeler wrote:

> I still don't see why I can't just copy the files from RAM directly  
> to the
> MMC.  I can mmcinit from uboot and then I can ls /mnt/mmc and see the
> contents of the card.  I've tried using cp.b to copy a binary file  
> to the
> mmc, but I think that command only points to flash memory and is  
> confused by
> anything else... it tells me can't copy to protected flash when I try

U-boot is not an operating system, it's a bootloader.  It includes  
some bare-bones read-only methods for accessing various devices, like  
MMC, CF, ethernet, but does not include any code to allow writing to  
most devices.  The idea is that u-boot is really supposed to just be  
enough to load & execute your OS kernel.  The OS is where you should  
generally be doing peripheral I/O beyond that needed to bootstrap the  
OS itself.

> GUM>loadb a2000000
> ...kermit send...success
> GUM>cp.b a2000000 mmc ${filesize}
>
> I know that must be wrong and that cp.b doesn't recognize "mmc" so  
> maybe it
> defaults to the beginning of flash (which is auto protected  
> methinks) and
> would account for the protected flash message I get.

Yup -- "cp" in u-boot takes memory addresses as both source and  
destination args.  "mmc" will be parsed as a hex string, ignoring any  
non-hex digits, yielding probably "0".  There is no way to write to a  
FAT filesystem on MMC (or any other media) from within u-boot; if you  
want to do I/O to a peripheral other than the minimal stuff needed to  
load & boot an OS, then you should do that from within the OS, not  
within u-boot.

> I suppose I need to actually dl and install lrzsz, but I've not  
> been able to
> find where to dl it.

Where you find it will depend on your distro.  Most of the time,  
you'll just use your distro's package manager to do something like  
"urmpi lrzsz" or "apt-get install lrzsz" or "emerge lrzsz"

C