switch from getty to root shell on console

this just makes things marginally simpler

doc/tutorial.rst

@@ -69,10 +69,11 @@ device's serial console and the `QEMU monitor
 stdin/stdout.
 
 You should now see Linux boot messages and after a few seconds be
-presented with a login prompt. You can login on the console as
-``root`` (password is "secret") and poke around to see what processes are
-running. To kill the emulator, press ^P (Control P) then c to enter the
-"QEMU Monitor", then type ``quit`` at the ``(qemu)`` prompt.
+presented with a root shell prompt.  You can run commands to look at
+the filesystem, see what processes are running, view log messages (in
+:file:/run/uncaught-logs.current), etc. To kill the emulator, press ^P
+(Control P) then c to enter the "QEMU Monitor", then type ``quit`` at
+the ``(qemu)`` prompt.
 
 To see that it's running network services we need to connect to its
 emulated network. Start the machine again, if you had stopped it, and

examples/hello-from-mt300.nix

@@ -8,7 +8,7 @@ in rec {
     ../modules/network
     ../modules/ssh
     ../modules/vlan
-    ../modules/flashimage.nix
+    ../modules/outputs/flashimage.nix
   ];
 
   boot.tftp = {

modules/s6/default.nix

@@ -80,10 +80,17 @@ let
       run = {
         file = ''
               #!${execline}/bin/execlineb -P
-              /bin/getty -l /bin/login 115200 /dev/console
+              ${execline}/bin/redirfd -w 2 /dev/console
+              ${execline}/bin/fdmove -c 1 2
+              ${execline}/bin/redirfd -r 0 /dev/console
+              ${execline}/bin/cd /
+              /bin/ash -l
           '';
         mode = "0755";
       };
+      down-signal = {
+        file = "HUP\n";
+      };
     };
     ".s6-svscan" =
       let

tests/ext4/script.expect

@@ -2,7 +2,6 @@ set timeout 10
 
 spawn socat unix-connect:vm/console -
 send "\r\n"
-expect "login:" {  send "root\r\n" }
 expect "#"
 send "echo HELLO WORLD > /hello\r\n"
 expect "#"

tests/jffs2/script.expect

@@ -2,7 +2,6 @@ set timeout 10
 
 spawn socat unix-connect:vm/console -
 send "\r\n"
-expect "login:" {  send "root\r\n" }
 expect "#"
 send "echo HELLO WORLD > /hello\r\n"
 expect "#"

tests/min-copy-closure/wait-until-ready.expect

@@ -2,4 +2,3 @@ set timeout 60
 
 spawn socat unix-connect:vm/console -
 send "\r\n"
-expect "login:"

tests/pppoe/getaddress.expect

@@ -2,7 +2,6 @@ set timeout 60
 
 spawn socat unix-connect:vm/console -
 send "\r\n"
-expect "login:" {  send "root\r\n" }
 expect "#"
 set FINISHED 0
 set EXIT "1" 

tests/wlan/wait-for-wlan.expect

@@ -2,7 +2,6 @@ set timeout 60
 
 spawn socat unix-connect:vm/console -
 send "\r\n"
-expect "login:" {  send "root\r\n" }
 expect "#"
 set FINISHED 0
 set EXIT "1"