--- wikisrc/ports/evbarm/raspberry_pi.mdwn	2020/10/15 19:56:44	1.134
+++ wikisrc/ports/evbarm/raspberry_pi.mdwn	2020/10/16 17:29:39	1.137
@@ -174,6 +174,13 @@ every few weeks.
 
  - <https://github.com/ebijun/NetBSD/blob/master/RPI/RPIimage/Image/README>
 
+## Boot Process
+
+https://www.raspberrypi.org/documentation/configuration/config-txt/boot.md
+
+Note that generally, a single dtb is loaded.  On NetBSD 9, the dtb
+file for the system is loaded by the bootloader (in flash).
+
 ## Configuring 802.11
 
 After installation, the Ethernet will function as on any other NetBSD system; simply enable dhcpcd or configure a static address.  USB WiFi devices will also function as on any other NetBSD system; in addition to dhcpcd or static, configure and enable wpa_supplicant.
@@ -218,16 +225,28 @@ The program vcgencmd, referenced in the 
 
 ## Updating dtb files
 
+### NetBSD 8
+
+On NetBSD 8, dtb files are not used. (\todo Really?)
+
+### NetBSD 9
+
 (This is harder than it should be.)
-Build a release.  gunzip the armv7.img, vnconfig it, and mount the MSDOS partition (e) e.g. on /mnt.  Copy the dtb files from /mnt/foo.dtb to /boot, and from /mnt/dtb/foo.dtb to /mnt/dtb.
+Build a release.  gunzip the armv7.img, vnconfig it, and mount the MSDOS partition (e) e.g. on /mnt.  Copy the dtb files from /mnt/foo.dtb to /boot, and from /mnt/dtb/foo.dtb to /boot/dtb.
+
+It seems that some systems, including RPI, require dtb files in /boot, and some expect them in /boot/dtb.
 
-It seems that some systems, including RPI, require dtb files in /boot, and some expect  them in /boot/dtb.
+\todo Explain if you only really need the right one for your system type.
 
 \todo Explain how one is supposed to be able to update these from the dtb files in releasedir/binary/kernel, or fix it to have the same structure.
 
+### NetBSD current
+
+When updating, ensure that /boot is mounted and that you unpack the dtb set.
+
 ## Updating the firmware
 
-It is highly likely that running NetBSD from a given branch X with firmware from a branch Y < X will not go well.  It is unclear if firmware from a branch Y > X will work.   It is standard practice to use firmware from the right branch.
+It is highly likely that running NetBSD from a given branch X with firmware from a branch Y < X will not go well.  It is unclear if firmware from a branch Y > X will work.  It is standard practice to use firmware from the right branch.
 
 A section below describes the process of updating NetBSD's copy of the firmware from upstream, with testing, by NetBSD developers.  This section is about updating a system's firmware from the firmware in a version of NetBSD.