[PATCH v1 6/8] configs: cyclone5: Enable SPL FAT support

[Jan Kiszka]

On 27.11.25 07:48, Sune Brian wrote:
>> But - as you introduced yourself - raw mode loading is broken for most
>> boards, specifically the DE0 Nano SoC. It uses sector-based raw mode by
>> default with an offset which only works by chance (if at all). If you
>> switch to partition ID mode (like the romloader), everything falls
>> apart. That's why I sent the other series. It may not yet be correct in
>> all details, though.
> 
> Hi Jan,
> 
> No additional trouble on here but just want to
> confirm how you run your DE0 board.
> 
> 1) Do you use a pure MMC boot? (no NOR Flash)

Yes.

> 2) You follow old boot flash method write
> aka placing "u-boot-with-spl.sfp" to A2.
> The "boot+rootfs" partition can be empty or
> not exist.
> So simply the entire sdmmc just contains A2 and
> u-boot can't pass SPL phase enter U-Boot phase?
> Are you having this trouble in the first place?

I shared our wks file [1]: We create a raw partition in a legacy msdos
table, set its system ID to 0xa2 (via [2] when we use a hybrid partition
table, or classically [3] before that), and put u-boot-with-spl.sfp into
it. SPL is picked up by the romloader, but SPL in upstream completely
fails to find u-boot proper in that partition. And that is first of all
because SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is enabled by default which
ignores any partitioning and only uses a hard-coded sector. If one
switches to SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE mode, other
bugs after 2a00d73d081a surface like no longer built code or wrong
offsets inside the partition, and you also end up without u-boot proper
being found. Whatever other partitions or partition tables exist on the
SD card does not matter for SPL loading u-boot proper.

Jan

[1]
https://gitlab.com/cip-project/cip-core/isar-cip-core/-/blob/fa81b7aa856049af984f404047a2005d251b6072/wic/de0-nano-soc.wks
[2]
https://gitlab.com/cip-project/cip-core/isar-cip-core/-/blob/fa81b7aa856049af984f404047a2005d251b6072/scripts/lib/wic/plugins/source/de0-nano-soc-firmware.py
[3]
https://github.com/ilbers/isar/blob/master/meta-isar/scripts/lib/wic/canned-wks/de0-nano-soc.wks.in

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