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* [U-Boot] Passing information from SPL to next stage
@ 2016-07-25  8:54 Chris Packham
  2016-07-25 14:51 ` Tom Rini
  0 siblings, 1 reply; 4+ messages in thread
From: Chris Packham @ 2016-07-25  8:54 UTC (permalink / raw
  To: u-boot

Hi,

Is there a standard way of passing information discovered by the SPL
onto the next boot stage?

I'm guessing for platforms that support the new driver model it's
possible to add/update information in the device-tree, but what about
platforms that don't currently use the new driver model.

I had a quick search of the mailing list and docs but didn't find
anything obvious. If I've missed something feel free to point me at
it.

Thanks,
Chris

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] Passing information from SPL to next stage
  2016-07-25  8:54 [U-Boot] Passing information from SPL to next stage Chris Packham
@ 2016-07-25 14:51 ` Tom Rini
  2016-07-25 23:51   ` Chris Packham
  0 siblings, 1 reply; 4+ messages in thread
From: Tom Rini @ 2016-07-25 14:51 UTC (permalink / raw
  To: u-boot

On Mon, Jul 25, 2016 at 08:54:27PM +1200, Chris Packham wrote:

> Hi,
> 
> Is there a standard way of passing information discovered by the SPL
> onto the next boot stage?
> 
> I'm guessing for platforms that support the new driver model it's
> possible to add/update information in the device-tree, but what about
> platforms that don't currently use the new driver model.
> 
> I had a quick search of the mailing list and docs but didn't find
> anything obvious. If I've missed something feel free to point me at
> it.

Just how much information is it?  The answer is somewhere between
'save_boot_params' (shove a tiny bit of data in a magic location) and
"switch to driver model, whack the DT prior to kicking off U-Boot",
depending also on size constraints.

-- 
Tom
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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] Passing information from SPL to next stage
  2016-07-25 14:51 ` Tom Rini
@ 2016-07-25 23:51   ` Chris Packham
  2016-07-25 23:57     ` Chris Packham
  0 siblings, 1 reply; 4+ messages in thread
From: Chris Packham @ 2016-07-25 23:51 UTC (permalink / raw
  To: u-boot

On Tue, Jul 26, 2016 at 2:51 AM, Tom Rini <trini@konsulko.com> wrote:
> On Mon, Jul 25, 2016 at 08:54:27PM +1200, Chris Packham wrote:
>
>> Hi,
>>
>> Is there a standard way of passing information discovered by the SPL
>> onto the next boot stage?
>>
>> I'm guessing for platforms that support the new driver model it's
>> possible to add/update information in the device-tree, but what about
>> platforms that don't currently use the new driver model.
>>
>> I had a quick search of the mailing list and docs but didn't find
>> anything obvious. If I've missed something feel free to point me at
>> it.
>
> Just how much information is it?  The answer is somewhere between
> 'save_boot_params' (shove a tiny bit of data in a magic location) and
> "switch to driver model, whack the DT prior to kicking off U-Boot",
> depending also on size constraints.
>

In our particular use-case we want to check for a specific input
character in SPL to launch a RAM test, otherwise proceed to a full
boot and possibly launch other diagnostics based on a different key.
The main point is we only want to call getc() once so the information
on what input character was received (or the result of interpreting
it) needs to go from SPL to the next stage if the input wasn't
something that the SPL cared about.

I'll take a look at save_boot_params.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] Passing information from SPL to next stage
  2016-07-25 23:51   ` Chris Packham
@ 2016-07-25 23:57     ` Chris Packham
  0 siblings, 0 replies; 4+ messages in thread
From: Chris Packham @ 2016-07-25 23:57 UTC (permalink / raw
  To: u-boot

On Tue, Jul 26, 2016 at 11:51 AM, Chris Packham <judge.packham@gmail.com> wrote:
> On Tue, Jul 26, 2016 at 2:51 AM, Tom Rini <trini@konsulko.com> wrote:
>> On Mon, Jul 25, 2016 at 08:54:27PM +1200, Chris Packham wrote:
>>
>>> Hi,
>>>
>>> Is there a standard way of passing information discovered by the SPL
>>> onto the next boot stage?
>>>
>>> I'm guessing for platforms that support the new driver model it's
>>> possible to add/update information in the device-tree, but what about
>>> platforms that don't currently use the new driver model.
>>>
>>> I had a quick search of the mailing list and docs but didn't find
>>> anything obvious. If I've missed something feel free to point me at
>>> it.
>>
>> Just how much information is it?  The answer is somewhere between
>> 'save_boot_params' (shove a tiny bit of data in a magic location) and
>> "switch to driver model, whack the DT prior to kicking off U-Boot",
>> depending also on size constraints.
>>
>
> In our particular use-case we want to check for a specific input
> character in SPL to launch a RAM test, otherwise proceed to a full
> boot and possibly launch other diagnostics based on a different key.
> The main point is we only want to call getc() once so the information
> on what input character was received (or the result of interpreting
> it) needs to go from SPL to the next stage if the input wasn't
> something that the SPL cared about.
>
> I'll take a look at save_boot_params.

Oh and I neglected to mention this board is based on the Freescale/NXP
T2081 so save_boot_params looks a little too ARM specific to be
helpful.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2016-07-25 23:57 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-07-25  8:54 [U-Boot] Passing information from SPL to next stage Chris Packham
2016-07-25 14:51 ` Tom Rini
2016-07-25 23:51   ` Chris Packham
2016-07-25 23:57     ` Chris Packham

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