RPI3 update from 8 to 9?

[Greg Troxel <gdt%lexort.com@localhost>]

This is sort of a report, and a request to tell me if I'm not before I
assume I'm right and put it in the HOWTO.


I have a RPI3 running 8, and I want to update it to 9.  I normally (x86)
do this by installing the new kernel, rebooting, unpacking userland,
merging etc, rebooting (using etcmanage's INSTALL-NetBSD and
hand-written not-yet-merged scripts for the kernel).

But, RPI3 has a bunch of stuff in /boot.  It seems bad to boot a
netbsd-9 kernel with the old /boot files.  (True?)

So I got the netbsd-9 armv7.img, vnconfig'd it, mounted it, and copied
the following to /boot:

  -rwxr-xr-x  1 root  wheel    52116 Jun 18 14:32 bootcode.bin
  -rwxr-xr-x  1 root  wheel     6660 Jun 18 14:32 fixup.dat
  -rwxr-xr-x  1 root  wheel     2618 Jun 18 14:32 fixup_cd.dat
  -rwxr-xr-x  1 root  wheel  2846852 Jun 18 14:32 start.elf
  -rwxr-xr-x  1 root  wheel   677732 Jun 18 14:32 start_cd.elf

I also copied EFI, but am guessing that was not necessary for RPI3.

With that, the old netbsd-8 kernel booted ok.

Interestingly, the dmesg changed slightly:

--- 20200705.0.netbsd-8 2020-06-20 23:14:57.402135064 -0400
  +++ 20200705.1.netbsd-8.newboot 2020-06-20 23:14:29.601580482 -0400
  @@ -9,2 +9,2 @@
  -total memory = 944 MB
  -avail memory = 924 MB
  +total memory = 948 MB
  +avail memory = 928 MB
  @@ -38 +38 @@
  -genfb0: framebuffer at 0xfd876000, size 1280x720, depth 32, stride 5120
  +genfb0: framebuffer at 0xfe876000, size 1280x720, depth 32, stride 5120
  @@ -76 +76 @@
  -sdhc0: SDHC 3.0, rev 153, platform DMA, 250000 kHz, HS 3.3V, re-tuning mode 1, 1024 byte blocks
  +sdhc0: SDHC 3.0, rev 153, platform DMA, 200000 kHz, HS 3.3V, re-tuning mode 1, 1024 byte blocks

I don't understand the shdc part; the rest  looks like maybe
improved/different firmware.


Next step is to swap in a netbsd-9 kernel7.img and boot.