[PATCH 24/30] arm: imx: Finish migration of CONFIG_CSF_SIZE to Kconfig

[Ye Li]

Hi Tom,

> -----Original Message-----
> From: Tom Rini <trini at konsulko.com>
> Sent: 2020年6月11日 20:12
> To: Ye Li <ye.li at nxp.com>
> Cc: u-boot at lists.denx.de; Stefano Babic <sbabic at denx.de>; Fabio Estevam
> <festevam at gmail.com>; dl-uboot-imx <uboot-imx at nxp.com>
> Subject: Re: [EXT] [PATCH 24/30] arm: imx: Finish migration of
> CONFIG_CSF_SIZE to Kconfig
> 
> On Thu, Jun 11, 2020 at 05:28:45AM +0000, Ye Li wrote:
> > Hi Tom,
> >
> > > -----Original Message-----
> > > From: Tom Rini <trini at konsulko.com>
> > > Sent: 2020年6月11日 4:16
> > > To: u-boot at lists.denx.de
> > > Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> > > <festevam at gmail.com>; dl-uboot-imx <uboot-imx at nxp.com>
> > > Subject: [EXT] [PATCH 24/30] arm: imx: Finish migration of
> > > CONFIG_CSF_SIZE to Kconfig
> > >
> > > Caution: EXT Email
> > >
> > > While the normal case of CSF_SIZE is handled via Kconfig we have
> > > entries in config headers related to CONFIG_SECURE_BOOT.  However in
> > > commit d714a75fd4dc ("imx: replace CONFIG_SECURE_BOOT with
> > > CONFIG_IMX_HAB") this was renamed to CONFIG_IMX_HAB.  Update
> the
> > > CSF_SIZE entry to have the correct default value if we have IMX_HAB
> > > enabled.
> > >
> > > Cc: Stefano Babic <sbabic at denx.de>
> > > Cc: Fabio Estevam <festevam at gmail.com>
> > > Cc: NXP i.MX U-Boot Team <uboot-imx at nxp.com>
> > > Fixes: d714a75fd4dc ("imx: replace CONFIG_SECURE_BOOT with
> > > CONFIG_IMX_HAB")
> > > Signed-off-by: Tom Rini <trini at konsulko.com>
> > > ---
> > >  arch/arm/mach-imx/Kconfig       | 1 +
> > >  include/configs/imx8mm_beacon.h | 4 ----
> > >  include/configs/imx8mm_evk.h    | 4 ----
> > >  include/configs/imx8mn_evk.h    | 4 ----
> > >  include/configs/imx8mp_evk.h    | 4 ----
> > >  include/configs/verdin-imx8mm.h | 4 ----
> > >  6 files changed, 1 insertion(+), 20 deletions(-)
> > >
> > > diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> > > index
> > > 6c3fedf665d6..0648c2725bf8 100644
> > > --- a/arch/arm/mach-imx/Kconfig
> > > +++ b/arch/arm/mach-imx/Kconfig
> > > @@ -52,6 +52,7 @@ config IMX_HAB
> > >
> > >  config CSF_SIZE
> > >         hex "Maximum size for Command Sequence File (CSF) binary"
> > > +       default 0x2000 if IMX_HAB
> > I suggest using "default 0x2000 if ARCH_IMX8M", because i.MX6/7 may also
> enable IMX_HAB.
> 
> So ARCH_IMX8M && IMX_HAB?  I would have expected the CSF size to be
> limited in all cases from the default value due to something security related
> eating up that 0x60 in overhead.  Is that not the case?  Thanks!

No, it is related to implementation on iMX8M. You don't need to add "&& IMX_HAB".  
But you could add 'depend on IMX_HAB' for the CSF_SIZE config. Because this config is
 only used when IMX_HAB is enabled.

This 0x60 overhead is actually for dek blob used by encrypted boot. While using fit 
on iMX8M, we will move this dek blob into fit as a standalone image, so it does not 
occupy extra space in CSF.

Best regards,
Ye Li

> 
> --
> Tom