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

[Robert P. J. Day]

  i'm sure there's a simple answer to this -- i built u-boot for my
beaglebone black using the "am335x_boneblack" config, which supports
saving env info to the eMMC HW partition boot1. but now that it's
there, is there a way i can manipulate that info with fw_printenv and
fw_setenv?

  that info is actually visible from the linux command line via the
special device file /dev/mmcblk1boot1, which i can hexdump if i wish:

# hexdump -C /dev/mmcblk1boot1 | less
00000000  fc d7 b6 21 61 72 63 68  3d 61 72 6d 00 62 61 75  |...!arch=arm.bau|
00000010  64 72 61 74 65 3d 31 31  35 32 30 30 00 62 6f 61  |drate=115200.boa|
00000020  72 64 3d 61 6d 33 33 35  78 00 62 6f 61 72 64 5f  |rd=am335x.board_|
00000030  6e 61 6d 65 3d 41 33 33  35 42 4e 4c 54 00 62 6f  |name=A335BNLT.bo|
00000040  61 72 64 5f 72 65 76 3d  30 41 35 43 00 62 6f 6f  |ard_rev=0A5C.boo|
00000050  74 5f 66 64 74 3d 74 72  79 00 62 6f 6f 74 61 72  |t_fdt=try.bootar|
... 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
#

so i'm guessing that was a really bad initial guess. i'm guessing i'd
need to add a line referring to the existing device file /dev/mmcblk1,
and add the actual HW partition offset and size, yes? i just have to
figure out what that is, if that's the way it's done.

rday

-- 

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

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
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