kgdb: add default generic stubs

The default kgdb functions can be implemented with common U-Boot functions,
so rather than force everyone to copy & paste these things, create a set of
weak stubs.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/common/kgdb_stubs.c b/common/kgdb_stubs.c
new file mode 100644
index 0000000..19b0c18
--- /dev/null
+++ b/common/kgdb_stubs.c
@@ -0,0 +1,64 @@
+/*
+ * U-boot - stub functions for common kgdb code,
+ *          can be overridden in board specific files
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <kgdb.h>
+
+int (*debugger_exception_handler)(struct pt_regs *);
+
+__attribute__((weak))
+void kgdb_serial_init(void)
+{
+	puts("[on serial] ");
+}
+
+__attribute__((weak))
+void putDebugChar(int c)
+{
+	serial_putc(c);
+}
+
+__attribute__((weak))
+void putDebugStr(const char *str)
+{
+#ifdef DEBUG
+	serial_puts(str);
+#endif
+}
+
+__attribute__((weak))
+int getDebugChar(void)
+{
+	return serial_getc();
+}
+
+__attribute__((weak))
+void kgdb_interruptible(int yes)
+{
+	return;
+}
+
+__attribute__((weak))
+void kgdb_flush_cache_range(void *from, void *to)
+{
+	flush_cache((unsigned long)from, (unsigned long)(to - from));
+}
+
+__attribute__((weak))
+void kgdb_flush_cache_all(void)
+{
+	if (dcache_status()) {
+		dcache_disable();
+		dcache_enable();
+	}
+	if (icache_status()) {
+		icache_disable();
+		icache_enable();
+	}
+}