Ultra96 boots from AVNet's SD card but not mine

Question

I have an Ultra96 that boots to the GUI using the 16Gb SD card that came with the unit.

When I create my own SD card that I've populated with my own code. I cannot boot at all.

The red "INIT_B" LED at DS7 stays lit and never switches to the green "DONE" LED at DS6. I have a USB-to-JTAG/UART Pod for the device, but no serial traffic is detected.

However, I don't believe that the board is even attempting to execute my code, because the same behavior is expressed when I copy the contents of the AVNet card's boot partition into my own card's boot partition. In this situation I would at least expect an attempt to boot, followed by a dump of errors on the monitor due to library mismatches.

Questions:

1. What is the meaning of the INIT_B and DONE LEDs? They are not described in the Ultra96 HW User's Guide. What software or firmware is responsible for turning on and off the LEDs?

2. Here are the results of fdisk -l run against my own SD card and the AVNet supplied card. Does anything look wrong in the way it was formatted?

Stock SD card:

root@Ultra96:/var/run/media/mmcblk0p1# fdisk -l /dev/mmcblk0

Disk /dev/mmcblk0: 14.9 GiB, 15931539456 bytes, 31116288 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x32f37a38

Device Boot Start End Sectors Size Id Type

/dev/mmcblk0p1 * 2048 2099199 2097152 1G b W95 FAT32

/dev/mmcblk0p2 2099200 16320511 14221312 6.8G 83 Linux

My SD card:

rich@rich-vbox ~/ultra96/u96_hackster/images/linux $ sudo fdisk -l /dev/sdb

[sudo] password for rich:

Disk /dev/sdb: 59.6 GiB, 64021856256 bytes, 125042688 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x01f31e0a

Device Boot Start End Sectors Size Id Type

/dev/sdb1 * 2048 2099199 2097152 1G b W95 FAT32

/dev/sdb2 2099200 125042687 122943488 58.6G 83 Linux

Message was edited by: Rich Dubielzig Added fixed-width formatting to fdisk outputs

Added fixed-width formatting to fdisk outputs

bhfletcher · Accepted Answer

I have tested Ultra96 Linux Boot using Delkin Devices 64GB and 128GB microSD cards from their Utility family. Therefore, I know that the hardware can handle the larger sizes. However, we have received other complaints specifically about the Samsung EVO. I'm not sure exactly what the issue is, but others have experienced boot problems with this specific brand of card.

This is a good read -- Storage Insights #1 - Why Not All SD Cards are Created Equal

We specifically chose Delkin Devices to include in our kits because of their "Controlled BOM." See https://www.delkin.com/blog/recognizing-the-importance-of-controlled-boms/ for more information.

If you'd like to give the larger Delkin Devices microSD cards a try, they are available through Newark, with 4, 8, 16, 64, and 128 GB cards currently in stock -- http://www.newark.com/w/search?st=delkin+microSD&product-range=utility-microsd-series&COM=Embedded

If you want an Industrial temperature grade microSD card, then look at Delkin's Utility+ family. Less varieties in stock, but perhaps enough to get you started -- http://www.newark.com/w/search?st=delkin+microSD&product-range=utilitypos-microsd-series&COM=Embedded

Regarding your previous questions about INIT_B and DONE, the operation of these signals from the MPSoC is defined in the Xilinx configuration documentation for the device -- https://www.xilinx.com/support/documentation/user_guides/ug570-ultrascale-configuration.pdf

INIT_B:
- Active-Low FPGA initialization pin or configuration error signal. The FPGA drives this pin Low when the FPGA is in a configuration reset state, when the FPGA is initializing (clearing) its configuration memory, or when the FPGA has detected a configuration error.
DONE:
- A High signal on the DONE pin indicates completion of the configuration sequence. By default, the DONE output is open-drain.

If the INIT_B is lit and the DONE is not, then you have experienced a boot error with the PL, which could definitely be caused by an incompatible microSD card.

Bryan

rich_dubielzig_rbt · Answer

The problem was related to my choice of SD card.

While I am marking Bryan's answer as correct, I did not go with a Delkin card, but rather a SanDisk Industrial 16Gb card, as that was the exact model that shipped with my Ultra96. Upon flashing the card, I was able to configure and boot the Ultra96.

https://www.newegg.com/Product/Product.aspx?Item=9SIAHRZ8851341

Just for posterity and future users, I note that I also tried these two cards, as I could pick them up at Fry's the same day and it turns out that Fry's doesn't carry any SD cards made for "Industrial" use. Neither worked.

Samsung PRO Endurance 32GB (fail to pass INIT_B state)

Patriot LX 16GB (free space on card smaller than factory reset image size).

Ultra96 boots from AVNet's SD card but not mine

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