[U-Boot] [PATCH v2 5/5] board: toradex: add colibri imx8qxp 2gb wb it v1.0b module support

[Peng Fan]

Hi Stefano,

> Subject: Re: [PATCH v2 5/5] board: toradex: add colibri imx8qxp 2gb wb it
> v1.0b module support
> 
> Hi Peng,
> 
> On 26/04/19 04:10, Peng Fan wrote:
> > Hi Stefano,
> >
> >> Subject: Re: [PATCH v2 5/5] board: toradex: add colibri imx8qxp 2gb
> >> wb it v1.0b module support
> >>
> >> Hi Marcel,
> >>
> >> On 25/04/19 14:35, Marcel Ziswiler wrote:
> >>> Hi Stefano
> >>>
> >>> On Thu, 2019-04-25 at 12:48 +0200, Stefano Babic wrote:
> >>>> Hi Marcel,
> >>>>
> >>>> On 09/04/19 17:25, Marcel Ziswiler wrote:
> >>>>> From: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> >>>>>
> >>>>> This commit adds initial support for the Toradex Colibri iMX8QXP
> >>>>> 2GB WB IT V1.0B module. Unlike the V1.0A early access samples
> >>>>> exclusively booting from SD card, they are now strapped to boot
> >>>>> from eFuses which are factory fused to properly boot from their
> >>>>> on-module eMMC. U- Boot supports either booting from the
> on-module
> >>>>> eMMC or
> >> may
> >>>>> be used for recovery purpose using the universal update utility
> >>>>> (uuu) aka mfgtools 3.0.
> >>>>>
> >>>>> Functionality wise the following is known to be working:
> >>>>> - eMMC and MMC/SD card
> >>>>> - Ethernet
> >>>>> - GPIOs
> >>>>> - I2C
> >>>>>
> >>>>> Unfortunately, there is no USB functionality for the i.MX 8QXP as
> >>>>> of yet.
> >>>>>
> >>>>> Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
> >>>>>
> >>>>> ---
> >>>>>
> >>>>
> >>>> I merged the series and build locally (fine), but Travis complains
> >>>> and stops with error:
> >>>>
> >>>> +cc1: fatal error: opening output file spl/u-boot-spl.cfgout: No
> >>>> +such
> >>>> file or directory
> >>>> +compilation terminated.
> >>>>
> >>>> Can you take a look at it ?
> >>>
> >>> Sure, looks like Peng's commit caceb739ea07 ("imx: build flash.bin
> >>> for
> >>> i.MX8") takes SPL for granted while my patchset currently avoids it.
> >>
> >> It looks so, yes.
> >>
> >>>
> >>> BTW: I still don't believe SPL makes much sense on i.MX 8X given all
> >>> the other proprietary parts involved in booting.
> >>
> >> SPL makes more sense if it is possible to detect at runtime the HW
> >> and change the configuration - for i.MX6, this means RAMS detection,
> >> which boot device is booting, and so on.
> >>
> >> On i.MX8 there is a lot of proprietary parts - we lose the
> >> flexibility of SPL, and most features are lost (or must be provided
> >> by proprietary code). I agree that on this platform SPL makes less
> >> sense, and i.MX8 should be built independently if CONFIG_SPL is set
> >> (this is also for
> >> i.MX6 / MX5, there are boards without SPL and using the DCD image to
> >> set up the RAM controller).
> >
> >
> > The reason we move to use SPL on i.MX8 is that we would like to avoid
> > bind ATF/OP-TEE/U-Boot into a flat image with hacked offset in an image.
> >
> 
> It seemed I have missed some point. Thanks for clarification. This makes
> sense.
> 
> > So the bootflow now is
> > SPL->ATF->OPTEE->ATF->U-Boot
> >
> > Without SPL, when generating flash.bin, we have to hack ATF to copy
> > OP-TEE image from flash.bin to the runtime location.
> 
> Nevertheless, I understand that it is not strictly required to enable OPTEE to
> boot the kernel, and in some applications a secure zone is not required. The
> thing is not that SPL is used here, but to constrain all other users like Marcel to
> do the same. With i.MX6, even if I strongly suggested to do this to allow run
> time detection, I let boards without SPL and with just u-boot.imx (with built-in
> DCD) to flow into mainline - the board maintainer rules as he knows better
> where the device is used.
> 
> So I will prefer that the build assume to have SPL just if SPL is configured and
> not in any case, letting boards without SPL (like this
> colibri-mx8) to build.

ok. Then need to think about how to bind bl31.bin and u-boot.bin,

the binded image will be copied to 0x80000000 by ROM.

Consider bl31 is 128KB now, so uboot entry could be hardcoded
to 0x80020000, and u-boot.bin is 128KB offset of the final image.

Could use binman. And then need to generate flash.bin.

Regards,
Peng.

> 
> >
> >>
> >>> Plus currently SPL
> >>> actually breaks the USB serial downloader aka recovery mode using
> >>> the universal update utility (uuu) aka mfgtools 3.0.
> >
> > The usb related function for i.MX8 is not ready now.
> 
> That is ok - it s WIP, it will be merged when ready. I agree with you, this is
> *not* a reason to avoid SPL.
> 
> > we are almost run out
> > of ocram with SPL DM, thinking to use OF_PLATDATA now, then move to
> > usb functions.
> 
> Understood.
> 
> Best regards,
> Stefano
> 
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