- Change the code that determines whether to use a serial console and

which serial device to use in that case respectively to not rely on
  the OFW names of the input/output and stdin/stdout devices. Instead
  check whether input and output refers to the same device and is of
  type serial (uart(4) was already doing this) and for the fallback
  to a serial console in case a keyboard is the selected input device
  but unplugged do the same for stdin and stdout in case the input
  device is nonexistent (PS/2 and USB keyboards) or has a 'keyboard'
  property (RS232 keyboards). Additionally also check whether the OFW
  did a fallback to a serial console in the same way in case the
  output device is nonexistent. While at it save on some variables
  and for sys/boot/sparc64/loader/metadata.c move the code in question
  to a new function md_bootserial() so it can be kept in sync with
  uart_cpu_getdev_console() more easily.
  This fixes selecting a serial console and the appropriate device
  when using a device path for the 'input-device' and 'output-device'
  OFW environment variables instead of an alias for the serial device
  to use or when using a screen alias that additionally denotes a
  video mode (like e.g. 'screen:r1024x768x60') but no keyboard is
  plugged in (amongst others). It also makes the code select a serial
  console in case the OFW did the same due to a misconfiguration like
  both 'input-device' and 'output-device' set to 'keyboard' or to a
  nonexisting device (whether the OFW does a fallback to a serial
  console in case of a misconfiguration or one ends up with just no
  console at all highly depends on the OBP version however).
- Reduce the size of buffers that only ever need to hold the string
  'serial' accordingly. Double the size of buffers that may need to
  hold a device path as e.g. '/pci@8,700000/ebus@5/serial@1,400000:a'
  exceeds 32 chars.
- Remove the package handle of the '/options' node from the argument
  list of uart_cpu_getdev_dbgport() as it's unused there and future
  use is also unlikely.

MFC after:	1 week

sys/boot/sparc64/loader/metadata.c

@@ -45,6 +45,8 @@ extern struct tlb_entry *itlb_store;
 extern int dtlb_slot;
 extern int itlb_slot;
 
+static int md_bootserial(void);
+
 /*
  * Return a 'boothowto' value corresponding to the kernel arguments in
  * (kargs) and any relevant environment variables.
@@ -68,8 +70,6 @@ static struct
 int
 md_getboothowto(char *kargs)
 {
-    char	buf[32], buf2[32];
-    phandle_t	options;
     char	*cp;
     int		howto;
     int		active;
@@ -126,25 +126,49 @@ md_getboothowto(char *kargs)
     for (i = 0; howto_names[i].ev != NULL; i++)
 	if (getenv(howto_names[i].ev) != NULL)
 	    howto |= howto_names[i].mask;
-    options = OF_finddevice("/options");
-    OF_getprop(options, "input-device", buf, sizeof(buf));
-    OF_getprop(options, "output-device", buf2, sizeof(buf2));
-    if (strncmp(buf, "tty", sizeof("tty") - 1) == 0 && strncmp(buf2, "tty",
-      sizeof("tty") - 1) == 0)
+    if (md_bootserial() != -1)
 	howto |= RB_SERIAL;
-    else if (strcmp(buf, "keyboard") == 0 && strcmp(buf2, "screen") == 0) {
-	phandle_t	chosen;
-	ihandle_t	stdin, stdout;
-
-	chosen = OF_finddevice("/chosen");
-	OF_getprop(chosen, "stdin", &stdin, sizeof(stdin));
-	OF_getprop(chosen, "stdout", &stdout, sizeof(stdout));
-	if (OF_instance_to_package(stdin) == OF_instance_to_package(stdout))
-	    howto |= RB_SERIAL;
-    }
     return(howto);
 }
 
+static int
+md_bootserial(void)
+{
+    char	buf[64];
+    ihandle_t	inst;
+    phandle_t	input;
+    phandle_t	node;
+    phandle_t	output;
+
+    if ((node = OF_finddevice("/options")) == -1)
+	return(-1);
+    if (OF_getprop(node, "input-device", buf, sizeof(buf)) == -1)
+	return(-1);
+    input = OF_finddevice(buf);
+    if (OF_getprop(node, "output-device", buf, sizeof(buf)) == -1)
+	return(-1);
+    output = OF_finddevice(buf);
+    if (input == -1 || output == -1 || OF_getproplen(input, "keyboard") >= 0) {
+	if ((node = OF_finddevice("/chosen")) == -1)
+	    return(-1);
+	if (OF_getprop(node, "stdin", &inst, sizeof(inst)) == -1)
+	    return(-1);
+	if ((input = OF_instance_to_package(inst)) == -1)
+	    return(-1);
+	if (OF_getprop(node, "stdout", &inst, sizeof(inst)) == -1)
+	    return(-1);
+	if ((output = OF_instance_to_package(inst)) == -1)
+	    return(-1);
+    }
+    if (input != output)
+	return(-1);
+    if (OF_getprop(input, "device_type", buf, sizeof(buf)) == -1)
+	return(-1);
+    if (strcmp(buf, "serial") != 0)
+	return(-1);
+    return(0);
+}
+
 /*
  * Copy the environment into the load area starting at (addr).
  * Each variable is formatted as <name>=<value>, with a single nul

sys/dev/uart/uart_cpu_sparc64.c

@@ -78,8 +78,8 @@ uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
 
 /*
  * Get the package handle of the UART that is selected as the console, if
- * the console is an UART of course. Note that we enforce that both stdin
- * and stdout are selected.
+ * the console is an UART of course. Note that we enforce that both input
+ * and output are selected.
  * Note that the currently active console (i.e. /chosen/stdout and
  * /chosen/stdin) may not be the same as the device selected in the
  * environment (ie /options/output-device and /options/input-device) because
@@ -91,32 +91,32 @@ uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
 static phandle_t
 uart_cpu_getdev_console(phandle_t options, char *dev, size_t devsz)
 {
-	char buf[32];
-	ihandle_t stdin, stdout;
-	phandle_t chosen, input;
+	char buf[sizeof("serial")];
+	ihandle_t inst;
+	phandle_t chosen, input, output;
 
 	if (OF_getprop(options, "input-device", dev, devsz) == -1)
 		return (-1);
-	if (OF_getprop(options, "output-device", buf, sizeof(buf)) == -1)
+	input = OF_finddevice(dev);
+	if (OF_getprop(options, "output-device", dev, devsz) == -1)
 		return (-1);
-	if (!strcmp(dev, "keyboard") && !strcmp(buf, "screen")) {
+	output = OF_finddevice(dev);
+	if (input == -1 || output == -1 ||
+	    OF_getproplen(input, "keyboard") >= 0) {
 		if ((chosen = OF_finddevice("/chosen")) == -1)
 			return (-1);
-		if (OF_getprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1)
+		if (OF_getprop(chosen, "stdin", &inst, sizeof(inst)) == -1)
 			return (-1);
-		if ((input = OF_instance_to_package(stdin)) == -1)
+		if ((input = OF_instance_to_package(inst)) == -1)
 			return (-1);
-		if (OF_getprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1)
+		if (OF_getprop(chosen, "stdout", &inst, sizeof(inst)) == -1)
 			return (-1);
-		if (OF_instance_to_package(stdout) != input)
+		if ((output = OF_instance_to_package(inst)) == -1)
 			return (-1);
 		snprintf(dev, devsz, "ttya");
-	} else {
-		if ((input = OF_finddevice(dev)) == -1)
-			return (-1);
-		if (OF_finddevice(buf) != input)
-			return (-1);
 	}
+	if (input != output)
+		return (-1);
 	if (OF_getprop(input, "device_type", buf, sizeof(buf)) == -1)
 		return (-1);
 	if (strcmp(buf, "serial") != 0)
@@ -132,9 +132,9 @@ uart_cpu_getdev_console(phandle_t options, char *dev, size_t devsz)
  * the OF.
  */
 static phandle_t
-uart_cpu_getdev_dbgport(phandle_t options, char *dev, size_t devsz)
+uart_cpu_getdev_dbgport(char *dev, size_t devsz)
 {
-	char buf[32];
+	char buf[sizeof("serial")];
 	phandle_t input;
 
 	if (!getenv_string("hw.uart.dbgport", dev, devsz))
@@ -158,7 +158,7 @@ uart_cpu_getdev_dbgport(phandle_t options, char *dev, size_t devsz)
 static phandle_t
 uart_cpu_getdev_keyboard(char *dev, size_t devsz)
 {
-	char buf[32];
+	char buf[sizeof("serial")];
 	phandle_t input;
 
 	if ((input = OF_finddevice("keyboard")) == -1)
@@ -181,7 +181,7 @@ uart_cpu_getdev_keyboard(char *dev, size_t devsz)
 int
 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 {
-	char buf[32], dev[32], compat[32];
+	char buf[32], compat[32], dev[64];
 	phandle_t input, options;
 	bus_addr_t addr;
 	int baud, bits, error, space, stop;
@@ -194,7 +194,7 @@ uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 		input = uart_cpu_getdev_console(options, dev, sizeof(dev));
 		break;
 	case UART_DEV_DBGPORT:
-		input = uart_cpu_getdev_dbgport(options, dev, sizeof(dev));
+		input = uart_cpu_getdev_dbgport(dev, sizeof(dev));
 		break;
 	case UART_DEV_KEYBOARD:
 		input = uart_cpu_getdev_keyboard(dev, sizeof(dev));