Raw Kernel Image Support for Falcon Mode Boot Via SPI Devices

[Nathan Barrett-Morrison]

Hi Tom,

Yes -- I believe this section of code should not be checking for IH_MAGIC
at all, as parse_image_header does it as well.

Would you like me to resubmit this patch with the offending lines deleted?

Sincerely,
Nathan

On Mon, Jan 31, 2022 at 10:14 AM Tom Rini <trini at konsulko.com> wrote:

> On Mon, Jan 17, 2022 at 08:02:58PM -0500, Nathan Barrett-Morrison wrote:
>
> > Hi All,
> >
> > While trying to bring up Falcon Mode boot on an ARM64 board, I've
> > discovered that the SPL+SPI(spl_spi.c) driver does not allow us to load a
> > raw kernel image and subsequently call the bootz_setup() function which
> > resides in spl_parse_image_header().
> >
> > I've added a new config option (CONFIG_SYS_SPI_KERNEL_SKIP_HEADER) which
> > will skip the mkimage header check, allowing the subsequent
> > spl_parse_image_header() call to successfully fall through to
> bootz_setup()
> > and load/boot a raw kernel image.
> >
> > Sincerely,
> > Nathan Barrett-Morrison
>
> > From e5a15a8ad2fd007e6d8d48dd64767d194bbd1833 Mon Sep 17 00:00:00 2001
> > From: Nathan Barrett-Morrison <nathan.morrison at timesys.com>
> > Date: Mon, 17 Jan 2022 19:42:59 -0500
> > Subject: [PATCH] Allow Falcon Mode boot to use raw kernel image when
> >  booting via SPI.  When using Falcon Mode boot with a raw, unwrapped
> kernel
> >  image, the bootz_setup() call inside of spl_parse_image_header() is
> >  unreachable because the mkimage header magic check will never pass.
> Adding
> >  CONFIG_SYS_SPI_KERNEL_SKIP_HEADER gives us the ability to pass through
> to the
> >  desired bootz_setup() call.
> >
> > Signed-off-by: Nathan Barrett-Morrison <nathan.morrison at timesys.com>
> > Cc: Tom Rini <trini at konsulko.com>
> > Cc: Aneesh V <aneesh at ti.com>
> > ---
> >  common/spl/spl_spi.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/common/spl/spl_spi.c b/common/spl/spl_spi.c
> > index 4e20a23dea..62dad1d2fb 100644
> > --- a/common/spl/spl_spi.c
> > +++ b/common/spl/spl_spi.c
> > @@ -33,8 +33,10 @@ static int spi_load_image_os(struct spl_image_info
> *spl_image,
> >       spi_flash_read(flash, CONFIG_SYS_SPI_KERNEL_OFFS, sizeof(*header),
> >                      (void *)header);
> >
> > +#ifndef CONFIG_SYS_SPI_KERNEL_SKIP_HEADER
> >       if (image_get_magic(header) != IH_MAGIC)
> >               return -1;
> > +#endif
> >
> >       err = spl_parse_image_header(spl_image, header);
> >       if (err)
>
> I'm not sure this is the right path.  Why is this part of the code
> checking for IH_MAGIC at all, and should it not instead allow for
> graceful falling back so that zImage/Image/etc work?
>
> --
> Tom
>