On Wed, 8 Apr 2015, Robert Nelson wrote:
> On Wed, Apr 8, 2015 at 9:14 AM, Robert P. J. Day <[email protected]>
> wrote:
> >
> > seeing differing opinions online ... if you read this:
> >
> > https://e2e.ti.com/support/arm/sitara_arm/f/791/t/233139
> >
> > i should be able to display the first few bytes of the BBB's EEPROM
> > from u-boot using:
> >
> > i2c md 0x50 0 16
> >
> > but, for me, that just displays "ff" throughout, which is what *other*
> > people claim to see when they try it.
> >
> > should this command work? do i need to initialize something first?
> > am i (theoretically) using the correct arguments?
>
> U-Boot# i2c probe
> Valid chip addresses: 24 34 50
> U-Boot# i2c md 0x24 0 16
> 0000: e2 3f 00 01 b1 80 b2 01 00 00 08 00 7f 0c 18 11 .?..............
> 0010: 09 06 09 38 26 3f ...8&?
> U-Boot# i2c md 0x34 0 16
> 0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 0010: 00 00 00 00 00 00 ......
> U-Boot# i2c md 0x50 0 16
> 0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> 0010: ff ff ff ff ff ff ......
ok, you're seeing what i'm seeing but shouldn't that last command
print the first 16 bytes of the EEPROM (header, board name, version)?
if i boot into linux, and:
# cd /sys/devices/ocp.3/44e0b000.i2c/i2c-0/0-0050
then i can certainly dump what corresponds to the EEPROM:
# hexdump -C eeprom | less
00000000 aa 55 33 ee 41 33 33 35 42 4e 4c 54 30 41 35 43 |.U3.A335BNLT0A5C|
00000010 32 37 31 33 42 42 42 4b 37 35 37 31 ff ff ff ff |2713BBBK7571....|
00000020 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
... snip ...
so can i not do that from within u-boot?
rday
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Robert P. J. Day Ottawa, Ontario, CANADA
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