Linux on NTV6

[RISCy Dude]

Hello mo123 and liftoff-sr, Thanks for the detailed answers. While I think I understand, you guys are shooting over my head here. Origionally I thought that Ugoos 15.04 was not working on the NT-V6's USB ports. Aware of their shared origins, I was curious as to why. It is clear now that I misunderstood the OP and that 15.04 works fine with the NT-V6.
I cut my teeth on old mainframes, like the DEC PDP 11/55(I'm old). I am slowly learning my way around Linux, but I won't live long enough to grasp it the way you folks have.

I do appreciate you guys taking the time to provide the explanations. However, it is obvious to me that I can add nothing to this conversation, so I will leave it to you more learned individuals.
Best wishes!

[liftoff-sr]

mo123:

You were right about the dtb being on the end of the zImage, at least the firefly repo kernel tree was causing that to be done.

UBOOT seems to know nothing about that and still tries to:

void rkimage_prepare_fdt(void)
{
gd->fdt_blob = NULL;
gd->fdt_size = 0;
#ifdef CONFIG_RESOURCE_PARTITION
resource_content content = rkimage_load_fdt(get_disk_partition(BOOT_NAME));
if (!content.load_addr) {
printf("failed to prepare fdt from boot!\n");
} else {
gd->fdt_blob = content.load_addr;
gd->fdt_size = content.content_size;
FBTDBG("prepare fdt from recovery:%p(%d)\n", gd->fdt_blob, gd->fdt_size);
return;
}
#ifdef CONFIG_OF_FROM_RESOURCE
content = rkimage_load_fdt(get_disk_partition(RESOURCE_NAME) );
if (!content.load_addr) {
printf("failed to prepare fdt from resource!\n");
} else {
gd->fdt_blob = content.load_addr;
gd->fdt_size = content.content_size;
FBTDBG("prepare fdt from resource:%p(%d)\n", gd->fdt_blob, gd->fdt_size);
return;
}
#endif
#endif
}

look for rk-kernel.dtb first in "boot" and if not found, then "resource" partitions.

However uboot could pass the kernel a dtb and it could be ignored by the kernel because they are after all two separate pieces of software. The kernel will do what it wants or is told to do. On other platforms you have to pass the address of the DTB to the kernel when jumping into it. I don't see that happening on the command line.

How can I get a serial port on this HPH during boot up? Do you know of a uart header and pinout, TTL? Or can the OTG port serve this purpose? (There are hints about that in uboot source.)

Thanks much.