Print an kernel error rather than panicing if init(8) exits abnormally.

This avoids the misimpression that a kernel bug happened and it avoids
clearing the screen of potentially useful information about an init(8)
crash.

init/init.8

@@ -218,10 +218,12 @@ graphics resolution (see
 .Sh EXIT STATUS
 .Nm
 exits 0 if the kernel should power off, exits 1 if the kernel should reboot, or
-exits 2 if the boot failed and the kernel should halt.
+exits 2 if the boot failed and the kernel should halt with a complaint about an
+.Nm
+fatality.
 Any other exit by the initial
 .Nm
-will trigger a kernel panic.
+will cause the kernel to halt with a complaint about an unexpected exit code.
 .Nm
 exits with the same exit status as its target session if it terminates normally.
 .Sh SEE ALSO

kernel/kernel.cpp

@@ -666,7 +666,10 @@ static void BootThread(void* /*user*/)
 		Log::Sync();
 		HaltKernel();
 	default:
-		PanicF("Init returned with unexpected return code %i", status);
+		Log::PrintF("kernel: fatal: init exited with unexpected exit code %i\n",
+		            status);
+		Log::Sync();
+		HaltKernel();
 	}
 }
 

share/man/man7/kernel.7

@@ -39,7 +39,10 @@ delimiter to stop kernel option parsing.
 The computer is powered off if the
 .Nm init
 process exits 0, rebooted if it exits 1,
-halted if it exits 2, and paniced otherwise.
+halted with an complaint about an
+.Nm init
+fatality if it exits 2, and halted with a complaint about an unexpected exit code
+otherwise.
 .Pp
 The options are as follows:
 .Bl -tag -width "12345678"