[U-Boot] Wandboard boot failure when HAB support is enabled

[Fabio Estevam <festevam@gmail.com>]

Hi Jon,

[Adding Breno on Cc, who is familiar with HAB support].

On Tue, Aug 27, 2019 at 3:03 PM Jon Szymaniak
<jon.szymaniak.foss@gmail.com> wrote:
>
> Hello all,
>
> I'd like to get U-Boot >= 2019.07 booting on a Wandboard Quad with HAB
> support enabled, but appear to be running into either some regressions
> (or matters of PEBKAC).  For the scope of this discussion, I'm only
> concerned with booting an "insecure" HAB-enabled U-Boot image (ideally
> FIT), on a device that has not yet been fused (i.e., with the U-Boot
> commands need to fuse and verify successful image authentication prior
> to enforcing ROM-based authentication of the SPL).
>
> As of commit df516569, I am able to use the default Wandboard
> configuration, enable HAB support (CONFIG_SECURE_BOOT=y) via
> menufconfig, build and then successfully boot the resulting SPL +
> u-boot-ivt.img combination on a Wandboard Quad (B1).
>
> However, as of commit 5b85858 (and onwards), I am no longer able to
> boot the second stage U-Boot image when HAB support is enabled (the
> SPL still works, however).  Disabling HAB support (the default
> configuration state) still works, of course.
>
> Issue #1: u-boot-ivt.img load address changed from 0x17800000 to 0x00000000
>
> It appears that the generation of u-boot-ivt.img "breaks" in df516569
> because the associated MKIMAGEFLAGS_u-boot-ivt.img definition, present
> in an else clause of the top-level Makefile, is no longer used, now
> that the default configuration enables SPL FIT support. As a result,
> the generated image contains a load address of 0x0, which results in a
> boot loop.
>
> I've tried to work around this with the following change, which leads
> me to Issue #2.  I'm unclear on whether a multi-DTB IVT image should
> be instead be produced to address this, or whether "legacy" boot
> images should continue to work.
>
> diff --git a/Makefile b/Makefile
> index f3857ab6a9..07fa36b4c1 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1243,12 +1243,13 @@ else
>  MKIMAGEFLAGS_u-boot.img = -A $(ARCH) -T firmware -C none -O u-boot \
>      -a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_UBOOT_START) \
>      -n "U-Boot $(UBOOTRELEASE) for $(BOARD) board"
> +endif
> +
>  MKIMAGEFLAGS_u-boot-ivt.img = -A $(ARCH) -T firmware_ivt -C none -O u-boot \
>      -a $(CONFIG_SYS_TEXT_BASE) -e $(CONFIG_SYS_UBOOT_START) \
>      -n "U-Boot $(UBOOTRELEASE) for $(BOARD) board"
>  u-boot-ivt.img: MKIMAGEOUTPUT = u-boot-ivt.img.log
>  CLEAN_FILES += u-boot-ivt.img.log u-boot-dtb.imx.log SPL.log u-boot.imx.log
> -endif
>
>  MKIMAGEFLAGS_u-boot-dtb.img = $(MKIMAGEFLAGS_u-boot.img)
>
>
> Issue #2: u-boot-ivt.img stuck in lib/hang.c's hang()
>
> Once executing u-boot-ivt.img from 0x17800000, I'm seeing the
> following call path occurring:
>
> board_init_f() -> initcall_run_list @ fdtdec_setup() errors out -->
> hang() -> bootstage_error(BOOTSTAGE_ID_NEED_RESET)
>
> I'm still trying to determine specifically where in fdtdec_setup() the
> failure is, but before I dig too much deeper, I was hoping to get some
> feedback on whether this is simply a matter of needing to produce a
> modified image that isn't currently being built.
>
> Again, I'm not entirely clear what the expectation is here -- should I
> simply not be attempting to boot the u-boot-ivt.img? Should this still
> work despite not being a FIT image?  Do we need to generate a
> FIT-based IVT image for this configuration?
>
>
> Thank you in advance for your time and help!
>
> Best regards,
> Jon Szymaniak