So . . .
william@beaglebone:~$ cat /uEnv.txt
##These are needed to be compliant with Angstrom's 2013.06.20 u-boot.
loadaddr=0x82000000
fdtaddr=0x88000000
rdaddr=0x88080000
<snip>
*loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/${uname_r}/${fdtfile}*
<snip>
*check_dtb=if test -n ${dtb}; then setenv fdtfile ${dtb};fi;*
<snip>
Ok, in order to understand fully what is happening here, we'd need to read
through the source for uboot, But I can in short tell you with reasonable
certainty what is going on here.
*loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/${uname_r}/${fdtfile}*
This is attempting to load the board device tree file from the first
partition of device mmc0. ${fdtaddr} is a variable created in this file
near the top, so we know what this is. ${fdtfile} however is not defined in
this file so we have to assume it is defined by uboots executable. How does
uboot do this ? We'd have to read the source code to be 100% sure, but like
I said I am reasonably sure that uboot reads from the eeprom, to make this
determination.
*check_dtb=if test -n ${dtb}; then setenv fdtfile ${dtb};fi;*
This, I'm not sure exactly what is going on. What is obvious however that
when some condition is met( this is the part im not sure of ), then the
environment variable fdtfile is set to environment variable dtb. I can make
several assumptions here what exactly ${dtb} *is*, but I would not feel
comfortable without reading through uboots source code . . .
Anyway, "we" can bypass a lot of this behavior simply by hard coding the
value for the required device tree file. However, if one burns up their
board( and this is possible )in the process. Then that is their own
responsibility.
On Tue, Apr 12, 2016 at 8:49 AM, William Hermans <[email protected]> wrote:
> #1 You're writing *what* to the eeprom ?
> #2 Which Linux image are you attempting to use ?
> #3 Which TI SDK ?
>
> So the Debian images now days I believe go by what is in eeprom, to decide
> which board file to load at boot. No properly formatted, or recognized
> eeprom, no board file detection, no boot.
>
> On Tue, Apr 12, 2016 at 5:13 AM, Sachin Sagar <[email protected]>
> wrote:
>
>> Hi,
>>
>> I am able to read/write the data from beagle bone black A5 after
>> disabling the WP . But after power cycle the board it is not getting
>> booted. Iam not getting why it is happening like this. Iam using ti SDK
>>
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