MASKROM: USB3 (type-A to type-A) needed?

[eselarm]

On my NanoPi-R6C I have been doing several U-boot updates (writes with dd to areas in 1st 32k) and so far so good. But behavior has changed w.r.t. eMMC v.s. SD-card.

I want to do some U-boot build config changes, so the risk it that something might go wrong and I would need USB MASKROM mode to do writes to eMMC I think.

The NanoPi-R6C wiki is not very clear with 'connect USB', but it turn out that  this should be a connection via type-A to type-A and it does not work in the USB2 port.

 

I have a USB2-only type-A to type-A cable and used that.

The NanoPi-R6C appears in the USB device list ('lsusb') and also the tool is seeing the device:

/tmp/upgrade_tool_v2.30_for_linux/upgrade_tool LD
Using /tmp/upgrade_tool_v2.30_for_linux/config.ini
List of rockusb connected(1)
DevNo=1 Vid=0x2207,Pid=0x350b,LocationID=12     Mode=Maskrom    SerialNo=

However, as soon as I want to read blocks from eMMC for example or try any other commands, connection is lost.

 

Now I think that maybe for actual data transfer, USB3 wires in the cable are needed, so the question is: Will it work when I buy/use an USB3 type-A to type-A cable?

 

Edited November 14 by eselarm

[Dantes]

I think you lose the connection because the kernel is loaded. I do not use the friendly elec tools. I just boot from an OpenWRT image.

• Get a USB-A to USB-C cable
• Connect USB-A to PC
• Connect USB-C to DEBUG port
• Use screen to connect to the NanoPi: (you might need sudo)

  screen /dev/ttyUSB0 1500000

• Get OpenWRT NanoPi-r6c image and write to sdcard
• Boot from sdcard with maskrom
• then you can use scp to transfer files
• and dd to write/erase/backup

I think I did something similar here:

 

[specs]

@dantes

"You might need sudo" generally means "if you regularly use a serial console or maskrom connection you will want to configure user permissions for /dev/ttyusbX" (i.e. adding the user to the "dialout" group).

Back when modems were still frequently used adding a user to dialout might have been a serious problem.

 

I think nowadays using sudo for pretty much anything is the greater risk.

[eselarm]

@DantesWhen I still had the original 2017 U-boot on the eMMC (from the OpenWRT that came pre-installed), inserting an SD-card with some recent Armbian image booted always from the SD-card. So in serial/debug console I had full control of the eMMC (and also an NVME in the M.2 slot). So that is also how I recently wrote a new/latest 2024 U-boot from the current-branch Armbian to the eMMC with dd.

But that 2024 U-boot is more flexible and I needed quite some time to and figure out what was what (after stop autoboot prompt):

1 - SD-card with a known good simple basic Armbian Bookworm

2 - eMMC where the custom kernel did not work

3 - NVME with an EFI boot partition with grub.efi and some variant of openSUSE and some Debian flavor

After reading U-boot command docs like 'bootflow', I somehow booted from NMVE. Fine but I want also operation with no NVME in the M.2 slot inserted.

So eMMC and SD-card can be selected in U-boot but was a bit guessing as I had to rely on some addresses, so 3rd try or so I started the good simple basic Armbian Bookworm from SD-card and from there I could put a working kernel Image/uInitrd/DTB on the eMMC again.

 

But what will happen if the somehow the U-boot on eMMC is corrupt? That has not happened, but when it would, will it then always somehow re-init and try SD-card? That is my point, that is why I thought I should also get to know USB loading, like I know from Android smartphones with fastboot tool.

 

But you state: "Boot from sdcard with maskrom", that I had not thought of. Does that skip eMMC always?

 

And scp? You mean the ethernet port(s) is/are up and running then? Or something over serial cable downloading what is known from simple old processor boards?