unicore32-softmmu: Add a minimal curses screen support

This patch adds a minimal curses screen support for unicore32-softmmu.
We assume 80*30 screen size to minimize the implementation.
Two problems are not solved, but they are innocuous.
1. curses windows will be blank when switching to monitor screen and back
2. backspace is not handled yet

v1->v2: add extra handler for '\r'
Signed-off-by: NZhang Mengchi <zhangmengchi@mprc.pku.edu.cn>
Signed-off-by: NGuan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

target-unicore32/helper.c

@@ -13,6 +13,7 @@
 #include "gdbstub.h"
 #include "helper.h"
 #include "host-utils.h"
+#include "console.h"
 
 #undef DEBUG_UC32
 
@@ -186,10 +187,50 @@ uint32_t helper_cp0_get(CPUUniCore32State *env, uint32_t creg, uint32_t cop)
     return 0;
 }
 
+#ifdef CONFIG_CURSES
+/*
+ * FIXME:
+ *     1. curses windows will be blank when switching back
+ *     2. backspace is not handled yet
+ */
+static void putc_on_screen(unsigned char ch)
+{
+    static WINDOW *localwin;
+    static int init;
+
+    if (!init) {
+        /* Assume 80 * 30 screen to minimize the implementation */
+        localwin = newwin(30, 80, 0, 0);
+        scrollok(localwin, TRUE);
+        init = TRUE;
+    }
+
+    if (isprint(ch)) {
+        wprintw(localwin, "%c", ch);
+    } else {
+        switch (ch) {
+        case '\n':
+            wprintw(localwin, "%c", ch);
+            break;
+        case '\r':
+            /* If '\r' is put before '\n', the curses window will destroy the
+             * last print line. And meanwhile, '\n' implifies '\r' inside. */
+            break;
+        default: /* Not handled, so just print it hex code */
+            wprintw(localwin, "-- 0x%x --", ch);
+        }
+    }
+
+    wrefresh(localwin);
+}
+#else
+#define putc_on_screen(c)               do { } while (0)
+#endif
+
 void helper_cp1_putc(target_ulong x)
 {
-    /* TODO: curses display should be added here for screen output. */
-    DPRINTF("%c", x);
+    putc_on_screen((unsigned char)x);   /* Output to screen */
+    DPRINTF("%c", x);                   /* Output to stdout */
 }
 #endif