1 files changed, 45 insertions, 0 deletions

diff --git a/arch/um/drivers/stderr_console.c b/arch/um/drivers/stderr_console.c
new file mode 100644
index 000000000000..98565b53d170
--- /dev/null
+++ b/arch/um/drivers/stderr_console.c
@@ -0,0 +1,45 @@
+#include <linux/init.h>
+#include <linux/console.h>
+
+#include "chan_user.h"
+
+/* ----------------------------------------------------------------------------- */
+/* trivial console driver -- simply dump everything to stderr                    */
+
+/*
+ * Don't register by default -- as this registeres very early in the
+ * boot process it becomes the default console.  And as this isn't a
+ * real tty driver init isn't able to open /dev/console then.
+ *
+ * In most cases this isn't what you want ...
+ */
+static int use_stderr_console = 0;
+
+static void stderr_console_write(struct console *console, const char *string,
+                                 unsigned len)
+{
+        generic_write(2 /* stderr */, string, len, NULL);
+}
+
+static struct console stderr_console = {
+        .name           "stderr",
+        .write          stderr_console_write,
+        .flags          CON_PRINTBUFFER,
+};
+
+static int __init stderr_console_init(void)
+{
+        if (use_stderr_console)
+                register_console(&stderr_console);
+        return 0;
+}
+console_initcall(stderr_console_init);
+
+static int stderr_setup(char *str)
+{
+        if (!str)
+                return 0;
+        use_stderr_console = simple_strtoul(str,&str,0);
+        return 1;
+}
+__setup("stderr=", stderr_setup);