[U-Boot] [PATCH 06/11] imx: imx-common: introduce boot auxiliary core

Stefan Agner
2016-01-14T17:54:24Z

On 2016-01-14 09:15, Tom Rini wrote:
> On Wed, Jan 13, 2016 at 12:45:05PM -0800, Stefan Agner wrote:
>> Hi,
>>
>> I would like to keep the discussion going and shed some light on the
>> image format introduced here, see below...
>>
>> On 2016-01-07 00:38, Peng Fan wrote:
>> > Hi Stefan,
>> > On Wed, Jan 06, 2016 at 10:59:17PM -0800, Stefan Agner wrote:
>> >>On 2016-01-04 21:56, Peng Fan wrote:
>> >>> From: Peng Fan <peng.fan@nxp.com>
>> >>>
>> >>> To boot a auxiliary core in asymmetric multicore system, introduce the
>> >>> new command "bootaux" to do it. Example of boot auxliary core from
>> >>> 0x70000000 where stores the boot head information that should be
>> >>> parsed by auxiliary core, "bootaux 0x70000000".
>> >>
>> >>This reminds me of a question which was nagging me lately:
>> >>Is the M4 core of SoloX/MX7 running a boot ROM? Or who/what is "parsing
>> >>the boot head information"?
>> >
>> > There is no bootrom for m4 core. The bootimage for M4 contains stack
>> > info and pc info. bootaux command will use the info extracted from bootimage.
>>
>>
>> So the image expected by bootaux is really a raw binary image, with the
>> only notion that the first two words need to be the stack pointer and
>> the reset handler (firmware entry point).
>>
>> U-Boot has other commands which work with "raw" images, such as the
>> bootz command. The bootz command also expects a certain "raw" format,
>> hence I guess it is ok to introduce something like that also for the
>> auxiliary core.
>
> I suppose my only contribution right now is that for another project
> where we have U-Boot (on the M4) kicking off NuttX we've had to do a
> custom command to stack pointer thing, I agree with the need to add some
> way to easily kick these cases off.

So the NuttX image was also kind of a raw image? Is that command
upstream?

--
Stefan