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

[Marek Vasut]

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.