[U-Boot] [EXT] Re: [PATCH 4/6] spl: mmc: support loading i.MX container format file

[Peng Fan]

> Subject: Re: [EXT] Re: [U-Boot] [PATCH 4/6] spl: mmc: support loading i.MX
> container format file
> 
> On 6/6/19 4:33 AM, Peng Fan wrote:
> >> Subject: Re: [EXT] Re: [U-Boot] [PATCH 4/6] spl: mmc: support loading
> >> i.MX container format file
> >>
> >> On Wed, Jun 05, 2019 at 03:24:40PM +0200, Marek Vasut wrote:
> >>> On 6/5/19 5:03 AM, Peng Fan wrote:
> >>> [...]
> >>>>>>>> It is not duplication of FIT. Container support the similar
> >>>>>>>> function of FIT image, but it is not only that.
> >>>>>>>
> >>>>>>> So what is it ?
> >>>>>>
> >>>>>>
> >>>>>
> >>
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.
> >>>>>>
> >>>>>
> >>
> nxp.com%2Fdocs%2Fen%2Freference-manual%2FIMX8DQXPRM.pdf&da
> >>>>> ta=02%7C
> >>>>>>
> >>>>>
> >>
> 01%7Cpeng.fan%40nxp.com%7C72216052f4234a93ad1f08d6e95ed782%7C6
> >>>>> 86ea1d3b
> >>>>>>
> >>>>>
> >>
> c2b4c6fa92cd99c5c301635%7C0%7C1%7C636952990895125305&sdat
> >>>>> a=KO%2B0e
> >>>>>>
> >>>>>
> >>
> E3v%2FkHuJ%2BhR7mBgc4NWXxbMUupfubXXu%2BueIWo%3D&reserv
> >>>>> ed=0
> >>>>>> Chapter 5 has information about container set and container.
> >>>>>
> >>>>> Thanks, any specific part of those 80 pages ?
> >>>>
> >>>> Figure 5-24. Container Format has a picture about a single container.
> >>>> i.MX8 container also support container sets, support encrypt blob,
> >>>> certificates, SRK management. Support signature to the whole
> >>>> container, no need single image inside container.
> >>>
> >>> Isn't that all supported in fitImage too ?
> >>
> >> This is neither the first nor last time functionality has been
> >> essentially duplicated, sadly, for reasons.
> >
> > I'll share the fit things to our ROM stakeholders, but they take
> > decision on new SoC design.
> >
> >>
> >>>>>>> I don't think I get it. Why would I, as an iMX8 user, want to
> >>>>>>> pick custom new vendor-specific format over years-proven generic
> >> fitImage?
> >>>>>>
> >>>>>> We not against FIT, we already use FIT on i.MX8M, to let spl to
> >>>>>> authenticate FIT image using ROM HAB, not using crypto driver.
> >>>>>
> >>>>> Great
> >>>>>
> >>>>>>> What is the selling point here ?
> >>>>>>
> >>>>>> We would not introduce cypto driver in SPL stage, that means HAB
> >>>>>> FIT and AHAB container needs to be dropped when SPL loading other
> >> images.
> >>>>>> ROM already provides API for bootloader to authenticate images,
> >>>>>> introducing complex crypto driver in SPL could enlarge code size
> >>>>>> and make things complicated.
> >>>>>
> >>>>> Ah I see, so it's all making the whole crypto simpler by
> >>>>> offloading the hard parts into the firmware, which just magically
> >>>>> handles everything , without having much extra code in the SPL ?
> >>>>
> >>>> Yes. Use what ROM provides will make things easier for U-Boot.
> >>>
> >>> Is it possible to perform a security audit on the ROM as easily as
> >>> on U-Boot ? I mean, U-Boot is free software, the source is
> >>> available, so security researchers can easily scrutinize it. Is the ROM ?
> >>
> >> So, here's my two cents (and it may or may not seem contradictory
> >> with my opinions in the secure boot thread going on currently on the
> >> Linaro Boot Architecture list).  Yes, it would and IMHO is better
> >> when we use free and open software to solve our problems (and an
> >> aside to the RISC-V folks as this is yet another area they can make
> >> the world a better place in).  But I am a believe in dealing with the
> >> world as it stands at times too.  The question isn't "can we get NXP
> >> to re-spin i.MX8 to use the FIT image format?" as that's obviously
> >> going to be "No.".  The question is, "can we support this format in a
> >> clean manner?" and the answer is obviously "Yes.".  So please lets
> >> keep that in mind with reviewing the code as at the end of the day it
> >> is more beneficial for this to be supported in mainline U-Boot than only
> supported in the vendor tree.
> >
> > Thanks. So I think you agree the current approach. Could I get any A-b
> > or R-b tags from the list?
> 
> I would still like an answer to my question about the security auditing above.

Sorry. Missed your thread. I not work on ROM stuff, but I think answer is
no to public. 

Thanks,
Peng.

> 
> --
> Best regards,
> Marek Vasut