[EXT] [PATCH] ARM: imx: romapi: Repair FlexSPI NOR boot offset

[Tim Harvey]

On Thu, Mar 31, 2022 at 9:41 AM Marek Vasut <marex at denx.de> wrote:
>
> On 3/31/22 18:03, Tim Harvey wrote:
> > On Thu, Mar 31, 2022 at 8:26 AM Marek Vasut <marex at denx.de> wrote:
> >>
> >> On 3/31/22 17:09, Tim Harvey wrote:
> >>> On Mon, Mar 28, 2022 at 7:55 AM Marek Vasut <marex at denx.de> wrote:
> >>>>
> >>>> On 3/28/22 08:54, Ye Li wrote:
> >>>>> Hi Marek,
> >>>>
> >>>> Hi,
> >>>>
> >>>> [...]
> >>>>
> >>>>>>> 2. Update the u-boot.itb offset in imx8mp-u-boot.dtsi, set the
> >>>>>>> offset
> >>>>>>> to 0x5f000.  The previous offset 0x58000 is for SD, calculated by
> >>>>>>> 0x60000 - 0x8000 (32KB image offset).
> >>>>>>>
> >>>>>>>                  uboot: blob-ext at 2 {
> >>>>>>>                          filename = "u-boot.itb";
> >>>>>>>                          offset = <0x5f000>;
> >>>>>>>                  };
> >>>>>> But that breaks booting from SD card for me ?
> >>>>>
> >>>>> Do you want to use one flash.bin for both SD and flexspi?
> >>>>
> >>>> Yes, the board I use can boot from SD/eMMC/FlexSPI. I don't want to
> >>>> build multiple confusing "flash.bin" files, one for each boot media.
> >>>>
> >>>>> When first introduced 8m support by imx8mimage.c, we expected the u-
> >>>>> boot.itb at same device offset (0x60000) on SD/emmc and flexspi. The
> >>>>> imx8mimage will calculate the offset inside the flash.bin automatically
> >>>>> according to different IVT offset. The ROMAPI driver also works
> >>>>> correspondingly.
> >>>>> After using binman, the u-boot.itb offset inside the flash.bin has to
> >>>>> be manually set in this DTS node. To follow the original design, this
> >>>>> offset should be different. That's why I asked to update this dts node
> >>>>> for flexspi.
> >>>>
> >>>> This does imply that there are currently no users that boot from flexspi
> >>>> in upstream U-Boot, because such users would have to manually modify
> >>>> both arch/arm/dts/imx8m?-u-boot.dtsi and board/*/imximage.cfg to
> >>>> generate suitable flash.bin which can be started from FlexSPI.
> >>>>
> >>>> Also, git grep confirms that there are no users:
> >>>>
> >>>> u-boot$ git grep BOOT_FROM.*fspi
> >>>> doc/imx/mkimage/imx8image.txt:BOOT_FROM
> >>>> [sd|emmc_fastboot|fspi|nand_4k|nand_8k|nand_16k] [sector_size]
> >>>>
> >>>>> If you change the ROM API driver, that will break our design. You can
> >>>>> try to overwrite spl_romapi_get_uboot_base for your board only.
> >>>>
> >>>> Since there are no users which boot from flexspi upstream, this design
> >>>> can still be fixed such that it does not require different flash.bin for
> >>>> different boot media, but rather one flash.bin works on all boot media.
> >>>> I think that is much better.
> >>>>
> >>>
> >>> Marek,
> >>>
> >>> I'm also a fan of single U-Boot binaries supporting multiple boards
> >>> and configurations.
> >>>
> >>> How are you handling env for the various boot devices? I haven't
> >>> looked in a while... can multiple env support co-exist now between
> >>> MMC/SPI and be selected at runtime?
> >>
> >> Do '$ git grep env_get_location' , you will find board-level examples
> >> where this function is implemented and it returns ENVL_* based on
> >> various hardware-specific conditions.
> >>
> >> I _think_ there is even imx arch specific implementation for this
> >> env_get_location() which automatically picks SD/eMMC/FlexSPI for you
> >> right now.
> >
> > Marek,
> >
> > I guess where I keep getting hung up is how to configure the ENV for
> > multiple env drivers as there is only one CONFIG_ENV_OFFSET Kconfig
> > which means for all devices your going to have the same offset/redund
> > configuration which is likely not appropriate for mmc/nand/spi for
> > example. I don't see any way currently to configure those separately.
> > Unless I'm missing something obvious I suppose get_env_location()
> > could be augmented to be able to return board-specific env location
> > config as well.
>
> e.g. env/mmc.c has the following:
>
>   78         } dt_prop = {
>   79                 .offset_redund = "u-boot,mmc-env-offset-redundant",
>   80                 .partition = "u-boot,mmc-env-partition",
>   81                 .offset = "u-boot,mmc-env-offset",
>   82         };
>
> So use that to specify per-env-driver offset. Indeed, the
> CONFIG_ENV*OFFSET is shared by all env driver.

Right... but I think the dt overrides there only exist for MMC (I
don't see then in env/nand.c for example)... but I can add that. I've
always wanted to have a single binary for IMX6 nand vs emmc boards and
this has been the ony hangup.

Thanks!

Tim