Opt: Add a libgba stub for interacting with debug registers

opt/libgba/mgba.c

@@ -0,0 +1,94 @@
+/*
+ mgba.h
+ Copyright (c) 2016 Jeffrey Pfau
+
+ Redistribution and use in source and binary forms, with or without modification,
+ are permitted provided that the following conditions are met:
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright notice,
+     this list of conditions and the following disclaimer in the documentation and/or
+     other materials provided with the distribution.
+ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <sys/iosupport.h>
+#include <gba_types.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <mgba.h>
+
+#define REG_DEBUG_ENABLE (vu16*) 0x4FFF780
+#define REG_DEBUG_FLAGS (vu16*) 0x4FFF700
+#define REG_DEBUG_STRING (char*) 0x4FFF600
+
+ssize_t mgba_stdout_write(struct _reent* r __attribute__((unused)), int fd __attribute__((unused)), const char* ptr, size_t len) {
+	if (len > 0x100) {
+		len = 0x100;
+	}
+	strncpy(REG_DEBUG_STRING, ptr, len);
+	*REG_DEBUG_FLAGS = MGBA_LOG_INFO | 0x100;
+	return len;
+}
+
+ssize_t mgba_stderr_write(struct _reent* r __attribute__((unused)), int fd __attribute__((unused)), const char* ptr, size_t len) {
+	if (len > 0x100) {
+		len = 0x100;
+	}
+	strncpy(REG_DEBUG_STRING, ptr, len);
+	*REG_DEBUG_FLAGS = MGBA_LOG_ERROR | 0x100;
+	return len;
+}
+
+void mgba_printf(int level, const char* ptr, ...) {
+	level &= 0x7;
+	va_list args;
+	va_start(args, ptr);
+	vsnprintf(REG_DEBUG_STRING, 0x100, ptr, args);
+	va_end(args);
+	*REG_DEBUG_FLAGS = level | 0x100;
+}
+
+static const devoptab_t dotab_mgba_stdout = {
+	"mgba_stdout",
+	0,
+	NULL,
+	NULL,
+	mgba_stdout_write
+};
+
+static const devoptab_t dotab_mgba_stderr = {
+	"mgba_stderr",
+	0,
+	NULL,
+	NULL,
+	mgba_stderr_write
+};
+
+bool mgba_console_open(void) {
+	if (!mgba_open()) {
+		return false;
+	}
+	devoptab_list[STD_OUT] = &dotab_mgba_stdout;
+	devoptab_list[STD_ERR] = &dotab_mgba_stderr;
+	return true;
+}
+
+bool mgba_open(void) {
+	*REG_DEBUG_ENABLE = 0xC0DE;
+	return *REG_DEBUG_ENABLE == 0x1DEA;
+}
+
+void mgba_close(void) {
+	*REG_DEBUG_ENABLE = 0;
+}

opt/libgba/mgba.h

@@ -0,0 +1,46 @@
+/*
+ mgba.h
+ Copyright (c) 2016 Jeffrey Pfau
+
+ Redistribution and use in source and binary forms, with or without modification,
+ are permitted provided that the following conditions are met:
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright notice,
+     this list of conditions and the following disclaimer in the documentation and/or
+     other materials provided with the distribution.
+ THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef MGBA_H
+#define MGBA_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MGBA_LOG_FATAL 0
+#define MGBA_LOG_ERROR 1
+#define MGBA_LOG_WARN 2
+#define MGBA_LOG_INFO 3
+#define MGBA_LOG_DEBUG 4
+
+bool mgba_open(void);
+void mgba_close(void);
+
+void mgba_printf(int level, const char* string, ...);
+bool mgba_console_open(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif