MMC prepare for zynq

[Gwenhael Goavec-Merou]

Hi,
After some tweaks:
- barebox is able to display prompt
- MMC is correctly configured
- Linux is correctly configured/enables to boot with console feedback.

I have sent a patch serie to fix these issues.

Thanks to all

Gwenhael

Le 05/07/2025 à 5:21 PM, Michael Graichen a écrit :
> Am 5. Juli 2025 09:01:38 MESZ schrieb Gwenhael Goavec-Merou <gwenj at trabucayre.com>:
>> Hi,
>> Thanks for informations: after deleting everything but the last two lines, barebox starts has expected.
>> Now I have and error with SDCard but maybe related to lines removes or something similar.
>>
> 
> Hey,
> 
> please show me the error messages once you put #define DEBUG at the top of mci-core.c
> 
> I'm also using a patches Version of drivers/mci/mci-core.c
> 
> First thing is that the amplitude of SD-Cards clock signal decreases with higher speed on Zynq-7000. I had to reduce SD-Cards speed to 25MHz within lowlevel.c. Next thing is mci-core.c does some speed and line testing that then causes error messages for my eMMC on the other line. So I skip this tests.
> 
> Since the board i'm working on doesn't change anymore, that's fine to me. But probably will not be good for other boards using mci-core.c
> 
> A feature to define fixed line nummers and speed mode from devicetree would be nice here?!
> 
> Have and nice weekend,
> Michael
> 
> 
> 
>> Thanks!
>>
>> Gwenhael
>>
>> Le 04/07/2025 à 7:38 PM, Johannes Roith a écrit :
>>> Hi Gwenhael, hi Ahmad
>>>
>>> Am Fri, Jul 04, 2025 at 04:56:01PM +0200 schrieb Ahmad Fatoum:
>>>> Hi Gwenhael,
>>>>
>>>> On 7/3/25 09:18, Gwenhael Goavec-Merou wrote:
>>>>> Dear all,
>>>>>
>>>>> I'm trying to uses my zedboard with barebox but can't be able to boot this.
>>>>>
>>>>> According to mails found in this mailing list I have done this sequence:
>>>>>
>>>>> export ARCH=arm
>>>>> export CROSS_COMPILE=$SOMEWHERE/arm-buildroot-linux-gnueabihf-
>>>>>
>>>>> make zynq_defconfig
>>>>> make -j$(nproc)
>>>>
>>>> That looks correct IMO.
>>>>
>>>>> And copied in the first SDCard FAT partition:
>>>>> - images/barebox-avnet-zedboard.img as BOOT.bin
>>>>> - barebox.bin
>>>>
>>>> Which binary is barebox.bin?
>>>
>>> The first one is the correct one. Just copy the images/barebox-avnet-zedboard.img
>>> with the name BOOT.bin to an SD-Card whose first partition is FAT32.
>>>>
>>>>> But I have nothing displayed through serial port.
>>>>
>>>> Two things come to mind:
>>>>
>>>> - The Image is 184K. Does the Zynq enforce a maximum limit on the BOOT.BIN?
>>>
>>> Yes, there is a limitation for the size of the First Stage Bootloader
>>> (FSBL) as Xilinx calls it, which is the available SRAM size in the ZYNQ
>>> 7000 (192 kBytes). Currently Barebox PBL and Barebox Proper are combined
>>> to one image (images/barebox-avnet-zedboard.img) but you will get an
>>> error in the build process, if your image exceeds this size.
>>>>
>>>> - Does DEBUG_LL produce any output? For details on how to configure
>>>> DEBUG_LL, see the troubleshooting guide I just Cc'd you on.
>>>>
>>>>> Are there somewhere details on how to prepare SD Card for a zynq board?
>>>>
>>>> I haven't done work with the Zynq 7000 so far, but Lucas and Johannes
>>>> did. I Cc'd them as they may be able to give some tips for troubleshooting.
>>>
>>> I would also take a look at this message on the mailing list:
>>>
>>> https://lore.barebox.org/barebox/DB7PR02MB43323CD77E0507E560475BCAABF00@DB7PR02MB4332.eurprd02.prod.outlook.com/
>>>
>>> Here, the content of the file
>>> arch/arm/boards/avnet-zedboard/zedboard.zynqcfg caused a boot error for
>>> barebox. With my Digilent Cora Z7 board, I also had to modify the file
>>> by deleting everything but the last line, to get barebox booting. Have
>>> you already tried this?
>>>
>>>>
>>>> Cheers,
>>>> Ahmad
>>>>
>>>>>
>>>>> Thanks
>>>>>
>>>>> Gwenhael
>>>>>
>>>>>
>>>>
>>>> -- 
>>>> Pengutronix e.K.                  |                             |
>>>> Steuerwalder Str. 21              | http://www.pengutronix.de/  |
>>>> 31137 Hildesheim, Germany         | Phone: +49-5121-206917-0    |
>>>> Amtsgericht Hildesheim, HRA 2686  | Fax:   +49-5121-206917-5555 |
>>>>
>>>
>>> Best regards,
>>> Johannes
>>
>>
>