Add missing debug.[ch]

2 files changed, 124 insertions, 0 deletions

diff --git a/src/cw-example/debug.c b/src/cw-example/debug.c
new file mode 100644
index 0000000..2e33a32
--- /dev/null
+++ b/src/cw-example/debug.c
@@ -0,0 +1,77 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Matthias P. Braendli
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+*/
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "debug.h"
+
+#if _DEBUG
+
+void debug_send_command(int command, void *message)
+{
+    __asm__ volatile (
+        "mov r0, %[cmd];"
+            "mov r1, %[msg];"
+            "bkpt #0xAB"
+            :
+            : [cmd] "r" (command), [msg] "r" (message)
+            : "r0", "r1", "memory");
+}
+
+void put_char(char c)
+{
+    __asm__ volatile (
+            "mov r0, #0x03\n"   /* SYS_WRITEC */
+            "mov r1, %[msg]\n"
+            "bkpt #0xAB\n"
+            :
+            : [msg] "r" (&c)
+            : "r0", "r1"
+        );
+}
+
+void debug_print(const char* str)
+{
+    const int std_err = 2;
+
+    int strlen = 0;
+    const char* s;
+    s = str;
+    while (*s) {
+        strlen++;
+        s++;
+    }
+
+    uint32_t m[] = { std_err, (uint32_t)str, strlen };
+    debug_send_command(0x05, m);
+}
+
+#else
+void debug_send_command(int command, void *message) { }
+void put_char(char c) { }
+void debug_print(const char* str) { }
+
+#endif
+
diff --git a/src/cw-example/debug.h b/src/cw-example/debug.h
new file mode 100644
index 0000000..6215e5f
--- /dev/null
+++ b/src/cw-example/debug.h
@@ -0,0 +1,47 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Matthias P. Braendli
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+*/
+
+/* Debugging utilities using the ARM semihosting facilities. Warning, it's quite
+ * slow.
+ *
+ * when used with OpenOCD's gdb server, requires the gdb command
+ *
+ * monitor arm semihosting enable
+ */
+#ifndef __DEBUG_H_
+#define __DEBUG_H_
+
+/* Example usage for the send_command function
+const char *s = "Hello world\n";
+uint32_t m[] = { 2, (uint32_t)s, sizeof(s)/sizeof(char) };
+send_command(0x05, m);
+// some interrupt ID
+
+*/
+
+/* Print a string to the OpenOCD console */
+void debug_print(const char* str);
+
+#endif // __DEBUG_H_
+