Hello,

Install notes are often the first thing a new OpenBSD user sees and
arm64 bootstrap doesn't even have a man page so clarify the boot.conf
file location here.

---

diff --git distrib/notes/arm64/install distrib/notes/arm64/install
index efd5f3819728..42ca2e4c7ea2 100644
--- distrib/notes/arm64/install
+++ distrib/notes/arm64/install
@@ -46,7 +46,9 @@ As you may have seen during installation, on some systems OpenBSD/MACHINE
 will configure the system console (displaying kernel messages, panics, and
 so on) to use the serial interface even though it has video hardware.
 To use video output on the framebuffer instead, you may add "set tty fb0"
-to /etc/boot.conf.
+to /etc/boot.conf (on the FFS partition, not FAT EFI partition); this can
+also be entered interactively at the boot> prompt to use installer without
+serial.
 
 In these cases the installer question about running X11 is not displayed;
 to start an X11 display manager at boot, use "rcctl enable xenodm".