[PATCH v4 5/8] doc: add DeepComputing FML13V01 documentation

[Maud Spierings]

On 4/24/25 13:26, E Shattow wrote:
> Overall I think this patch is acceptable as-is and I'll be willing to
> make a later series with my suggestions; it's documentation so it is
> never really completed, I think, and I spend an hour or two editing then
> decide that what I want to do is its own other series. None of the what
> I'd like to suggest here should delay a PR for this series.
> 
> On 4/24/25 05:13, Heinrich Schuchardt wrote:
>> Describe building U-Boot for the board and booting.
>> 
>> Carve out common information for JH7110 boards into an include.
>> 
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
>> ---

[...]

>> +Booting from SD-Card
>> +--------------------
>> +
>> +The device boot ROM loads U-Boot SPL (u-boot-spl.bin.normal.out) from the
>> +partition with type GUID 2E54B353-1271-4842-806F-E436D6AF6985. You are free
>> +to choose any partition number.
>> +
>> +With the default configuration U-Boot SPL loads the U-Boot FIT image
>> +(u-boot.itb) from partition 2 (CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=0x2).
>> +When formatting it is recommended to use GUID
>> +BC13C2FF-59E6-4262-A352-B275FD6F7172 for this partition.
>> +
>> +Booting from eMMC
>> +-----------------
>> +
>> +The device boot ROM tries to load U-Boot SPL (u-boot-spl.bin.normal.out) from
>> +sector 0 of the eMMC's main hardware partition. But this conflicts with GPT
>> +partitioning. Fortunately eMMC can alternatively load U-Boot SPL from a backup
>> +position.
>> +
>> +For U-Boot SPL (u-boot-spl.bin.normal.out) starting at sector 2048 (position
>> +0x100000) write the following bytes to the eMMC device after GPT partitioning:
>> +
>> +======= ========================
>> +Address Bytes
>> +======= ========================
>> +0x0000  40 02 00 00  00 00 10 00
>> +0x0290  40 02 00 00  00 00 10 00
>> +======= ========================
>> +
>> +With the default configuration U-Boot SPL loads the U-Boot FIT image
>> +(u-boot.itb) from partition 2 (CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=0x2).
>> +When formatting it is recommended to use GUID
>> +BC13C2FF-59E6-4262-A352-B275FD6F7172 for this partition.
>> +
>> +Booting from UART
>> +-----------------
>> +
>> +The boot ROM supports the X-modem protocol to upload
>> +spl/u-boot-spl.bin.normal.out. U-Boot SPL support loading the FIT image
>> +u-boot.itb via the Y-modem protocol.
>> +
>> +Due to restrictions of the boot ROM not all X-modem implementations are
>> +compatible. The package tio (https://github.com/tio/tio) has been found to be
>> +usable.
> 
> JH7110 Boot User Guide says "Since document release 1.2, boot from SD
> Card or eMMC is no longer recommended. But to maintain the code
> structure, the following SD/eMMC boot address allocations are modified
> as "reserved". Be aware of this change when designing your device based
> on JH7110." [1]
> 
> 1:https://doc-en.rvspace.org/VisionFive2/Developer_Guide/JH7110_Boot_UG.pdf
> 
> So this is important we preserve documentation how SD-card and eMMC Boot
> source modes can be prepared that are since dropped from official
> documentation. Yet on my patch for bootph-pre-ram device-tree hints to
> LKML there is Hal (StarFive) and some other people that want this
> functionality of SD-card and eMMC boot to remain working in U-Boot even
> though it's recommended against and dropped from official StarFive
> documentation.

Can confirm that I would like this functionality to stay, as I've used 
it a couple of times already on the fml13v01 board specifically to test 
firmware before flashing it to spi flash.

I believe it is actually the default boot mode selected by deepcomputing 
on new boards, but don't quote me on that.

I have only confirmed the sd card to work though, since my eMMC is my 
main drive and is already full of efi/bootfs/rootfs.

I should try that uart booting at some point, I already use tio. Would 
love to see a more detailed how to on it. I guess set to uart, then 
ctrl+t x and then just send the spl, then ctrl+t x to send the FIT?

Kind regards,
Maud

> I don't know, which is it? This appears to be an academic exercise to
> make those deprecated boot modes working. It certainly belongs in
> jh7110_common.rst as something interesting the hardware may be capable
> of, but not as the recommended standard operating procedure.
> 
> @ Hal can you describe what the JH7110 boot code is doing for SD-card
> and eMMC Boot modes? What magic numbers and logic is this process? If
> you want these boot modes to be functional then please help with the
> documentation here that is now deleted from StarFive officially.
> 
> With that,
> 
> Reviewed-by: E Shattow <e at freeshell.de>