Re: colibri_vf: CONFIG_TEXT_BASE and the Toradex eBoot flashing path

[Francesco Dolcini <francesco@dolcini.it>]

Hello Mehmet

On Thu, Aug 06, 2026 at 02:48:16PM +0200, Mehmet Fide wrote:
> From: Mehmet Fide <mehmet.fide@screeningeagle.com>
> 
> Hi,
> 
> a report rather than a patch, because I am not sure which way you want it
> solved.
> 
> Colibri VF50/VF61 modules that still carry the Toradex WinCE bootloader
> (here: "Toradex Bootloader 1.7 for Vybrid Built May 1 2020") are flashed in
> production by handing U-Boot to that loader:
> 
> 	> flashloader colibri_vf/u-boot-nand.imx
> 	Bootloader image size: 455448 bytes.
> 	Loading done.
> 	Flashing bootloader.
> 	Writing 223 sector(s) of bootloader code from sector 64.
> 	Flashing completed.
> 	> reboot

what if you powercycle the board, instead of doing a reboot?

> 
> With colibri_vf_defconfig as it is today, CONFIG_TEXT_BASE=0x3f401000, the
> module then prints nothing at all: no banner, no character, on a console
> that works before and after. Building the very same tree with
> CONFIG_TEXT_BASE=0x3f408000, the value the Toradex 2015.04 fork used, the
> image boots normally and the rest of the flashing flow (NAND partitions,
> Linux) completes.
> 
> The difference is only where the image lands in OCRAM:
> 
> 	0x3f401000: IVT entry 0x3f401000, image start 0x3f4004e8, len 0x6d000
> 	0x3f408000: IVT entry 0x3f408000, image start 0x3f4074e8, len 0x6d000
> 
> Our reading is that the loader is still resident when it copies the image
> in, so an image linked at the start of OCRAM overwrites the code doing the
> copy, while 0x3f408000 leaves the low 32 KB alone; we have not proved where
> exactly the loader keeps itself, so treat that as a guess. What is measured
> is the boot/no-boot difference above, on the same module, same card, same
> command, one build apart.
> 
> Booting the same 0x3f408000 image from NAND through the boot ROM works too,
> so the older base is not specific to the eBoot path.
> 
> Is the eBoot path still considered supported for these modules, in which
> case colibri_vf_defconfig would want to go back to 0x3f408000, or is it
> obsolete in favour of recovery mode, in which case it may be worth a note in
> doc/board/toradex? I am happy to send either patch.

I know very little on this board, eBoot and all the related, but my
advise would be the following, U-Boot here should be standalone, and it
should be possible to flash it from scratch on the device.

I would not focus on whatever you are getting pre-programmed on the
board, apart maybe some note in the documentation.

Francesco