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

[Tim Harvey]

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.

Best regards,

Tim