[U-Boot] can u-boot tools fw_{printenv, setenv} work with eMMC HW partition?

[Robert P. J. Day]

On Fri, 23 Aug 2013, Andreas Bießmann wrote:

> Dear Robert P. J. Day,
>
> On 08/23/2013 02:25 PM, Robert P. J. Day wrote:
>
> <snip>
>
> > so it's clearly there, but i have no idea what i'd put in
> > /etc/fw_env.config to refer to that partition.
> >
> >   i tried adding the simple line:
> >
> > /dev/mmcblk1boot1       0x0     0x4000
> >
> > to (allegedly) represent a block device, but i got the error:
> >
> > # fw_printenv
> > Cannot access MTD device /dev/mmcblk1boot: No such file or directory
> > #
>
> I think you stumble over this:
>
> ---8<---
> abiessmann at punisher % grep -C 4 'struct envdev_s' tools/env/fw_env.c
> 	typeof(y) _min2 = (y);			\
> 	(void) (&_min1 == &_min2);		\
> 	_min1 < _min2 ? _min1 : _min2; })
>
> struct envdev_s {
> 	char devname[16];		/* Device name */
> 	ulong devoff;			/* Device offset */
> 	ulong env_size;			/* environment size */
> 	ulong erase_size;		/* device erase size */
> 	ulong env_sectors;		/* number of environment sectors */
> 	uint8_t mtd_type;		/* type of the MTD device */
> };
> --->8---
>
> An device name can only have 16 char by this declaration ;)

  good lord, you're right, that explains why the last character of the
device file was getting mysteriously dropped. :-( so as a quick hack,
i just did a "mknod" (i suspect a symlink would have worked just as
well) to invent a shorter name, "/dev/mmcboot1", and got
(predictably):

# fw_printenv
Cannot get MTD information: Invalid argument
#

which leads me into stefano's response which i just saw.

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

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