From 57a7e1c2d42481849a9c2adcd6e7955a208c0645 Mon Sep 17 00:00:00 2001
From: lephe <sebastien.mld@numericable.fr>
Date: Thu, 13 Apr 2017 21:59:13 +0200
Subject: [PATCH] More quality review, more registers saved at startup.

---
 Makefile                       |  34 +++++-
 TODO                           |  44 ++++----
 demo/gintdemo.c                |   4 +-
 demo/test_bopti.c              |   6 +-
 demo/test_rtc.c                |  40 +++----
 demo/test_timer.c              |   4 +-
 include/bopti.h                |  14 ++-
 include/gint.h                 |   3 -
 include/internals/bopti.h      | 130 ++++++++++++-----------
 include/internals/gint.h       |  81 +++++++++++---
 include/internals/keyboard.h   |   5 +-
 include/internals/mmu.h        |   4 +-
 include/internals/rtc.h        | 125 ++--------------------
 include/modules/macros.h       |   9 ++
 include/modules/rtc.h          | 131 +++++++++++++++++++++++
 include/modules/timer.h        |   2 +-
 include/mpu.h                  |   2 +-
 include/rtc.h                  |  27 ++---
 src/bopti/bopti_internals.c    |  54 ++++------
 src/bopti/dimage.c             |   6 +-
 src/bopti/gimage.c             |   4 +-
 src/clock/clock.c              |   4 +-
 src/core/crt0.c                |  20 ++--
 src/core/exceptions.c          |   4 +-
 src/core/gint.c                |  13 +--
 src/core/gint_sh7305.c         | 189 ++++++++++++++++-----------------
 src/core/gint_sh7705.c         | 136 +++++++++++++-----------
 src/core/gint_vbr.s            |   2 +-
 src/core/init_quit.c           |  17 ++-
 src/core/modules.c             |  13 ++-
 src/core/mpu.c                 |  13 +--
 src/keyboard/keyboard_sh7305.c |   5 +-
 src/rtc/rtc_callback.c         |  16 +--
 src/rtc/rtc_getTime.c          |  34 +++---
 src/rtc/rtc_interrupt.c        |   6 +-
 src/rtc/rtc_setTime.c          |  31 +++---
 src/time/time.c                |   3 +-
 version                        |   1 +
 38 files changed, 673 insertions(+), 563 deletions(-)
 create mode 100644 include/modules/rtc.h
 create mode 100644 version

diff --git a/Makefile b/Makefile
index 04677b1..26db109 100755
--- a/Makefile
+++ b/Makefile
@@ -104,7 +104,7 @@ hdr-dep = $(wildcard include/*.h include/*/*.h)
 
 
 #---
-#	Rule templates.
+#	Rule templates
 #---
 
 # C source file template:
@@ -129,7 +129,29 @@ endef
 
 
 #---
-#	Building.
+#	Version management
+#---
+
+# Retrieve version information.
+version_string	:= $(shell cat version | sed 's/[-.]/ /g')
+version_type	:= $(word 1,$(version_string))
+version_major	:= $(word 2,$(version_string))
+version_minor	:= $(word 3,$(version_string))
+version_build	:= $(word 4,$(version_string))
+
+# Bump build number and make up the new version integer.
+version_build	:= $(shell echo $$(($(version_build) + 1)))
+version_letter	:= $(shell echo -n $(version_type) | sed -r 's/^(.).*/\1/')
+version_symbol	:= $(shell printf '0x%02x%01x%01x%04x' "'$(version_letter)'" \
+		$(version_major) $(version_minor) $(version_build))
+
+# Tell the linker to define the version symbol.
+ldflags += -Wl,--defsym,GINT_VERSION=$(version_symbol)
+
+
+
+#---
+#	Building
 #---
 
 # Generic rules
@@ -142,16 +164,20 @@ build:
 	$(if $(VERBOSE),,@ printf '\e[35;1mdir \u00bb\e[0m mkdir $@\n')
 	$(if $(VERBOSE),,@) mkdir -p $@
 
+version: $(obj-std) $(obj-lib)
+	@ echo '$(version_type)-$(version_major).$(version_minor)-$(version_build)' > $@
+
+
 $(obj-std) $(obj-lib) $(demo-obj): | build
 
-$(target-std): $(obj-std)
+$(target-std): $(obj-std) version
 	$(if $(VERBOSE),,@ printf '\e[35;1mlib \u00bb\e[0m ar $@\n')
 	$(if $(VERBOSE),,@) $(ar) rcs $@ $(obj-std)
 	@ printf '\e[32;1mmsg \u00bb\e[0m Succesfully built libc ('
 	@ printf $$(stat -c %s $@)
 	@ printf ' bytes)\n\n'
 
-$(target-lib): $(config) $(target-std) $(obj-lib)
+$(target-lib): $(config) $(target-std) $(obj-lib) version
 	$(if $(VERBOSE),,@ printf '\e[35;1mlib \u00bb\e[0m ar $@\n')
 	$(if $(VERBOSE),,@) $(ar) rcs $@ $(obj-lib)
 	@ printf '\e[32;1mmsg \u00bb\e[0m Succesfully built libgint ('
diff --git a/TODO b/TODO
index 9134ce0..88f4c3c 100644
--- a/TODO
+++ b/TODO
@@ -1,37 +1,37 @@
 Bugs to fix:
 -  A few key hits ignored after leaving the application  (could not reproduce)
 -  Lost keyboard control at startup                      (could not reproduce)
--  Influence of keyboard on some timers and RTC (maybe interrupt priority)
 -  Alignment of ALL .data / .rodata files is required to ensure converted data
    is properly aligned
+-  Reported video ram overflow when rendering text at borderline positions 
 
-Simple improvements:
--  demo:	Try 284x124 at (-60, -28) (all disadvantages)
--  display:	Rectangle-based drawing functions
--  time:	Compute CLOCKS_PER_SEC
--  string:	Use cmp/str to implement memchr() (assembler examples)
--  string:	Do some tests for memcmp()
--  core:	Register more interrupts (and understand their parameters)
--  project:	Clean headers that have some internal definitions
--  project:	Check size of all library structures
-Larger improvements:
--  errno:	Introduce errno and use it more or less everywhere
--  bopti:	Monochrome bitmaps blending modes
--  bopti:	Handle partial transparency
--  core:	Implement all callbacks and a complete user API
-*  core:	Better save registers
+Things to do before 1.0:
+-  bopti:	Test partial transparency
 *  core:	Allow return to menu
--  serial:	Implement a driver
--  usb:		Implement a driver
--  esper:	Cleaner playback, synthesizing
--  clock:	Handle overclock (relaunch clocks when overclocking)
+-  demo:	Try 284x124 at (-60, -28) (all disadvantages)
+-  display:	Implement rectangle-based drawing functions
+-  project:	Add a real build-based version system
+-  project:	Check size of *all* library structures
+-  project:	Clean headers that have some internal definitions
 -  project:	Unify this hellish mess of register access!
+-  time:	Compute CLOCKS_PER_SEC
+
+Things to do later:
+-  bopti:	Implement blending modes for monochrome bitmaps
+-  clock:	Handle overclock (relaunch clocks when overclocking)
+-  core:	Register more interrupts (and understand their parameters)
+-  core:	Remove redundant code linked to environment saves
+-  core:	Review interrupt system (again) - this one is too slow
+-  errno:	Introduce errno and use it more or less everywhere
+-  esper:	Cleaner playback, synthesizing
+-  serial:	Implement a driver
+-  string:	Use cmp/str to implement memchr() (assembler examples)
+-  string:	Do some tests for memcmp() and memcpy()
+-  usb:		Implement a driver
 
 Things to investigate:
 -  Packed bit fields alignment
 -  Registers that may need to be saved within setjmp()
--  Registers that may need to be saved and restored by gint
 -  Optimizing core/gint.c leads to raising of an illegal slot exception when
    running the interrupt handler, although it ends on rte; lds.l @r15+, mach,
    which is totally not an illegal slot.
--  Check version registers on SH7705
diff --git a/demo/gintdemo.c b/demo/gintdemo.c
index 98d1ac5..41e4d6e 100644
--- a/demo/gintdemo.c
+++ b/demo/gintdemo.c
@@ -345,8 +345,8 @@ void main_menu(int *category, int *app)
 		switch(tab)
 		{
 		case 0:
-			locate(1, 1, "Demo application");
-			print(2, 3, "gint version: %5s", GINT_VERSION_STR);
+			print(1, 1, "Demo application");
+//			print(2, 3, "gint version: %5s", GINT_VERSION_STR);
 			print(2, 4, "handler size: %5d", gint_size);
 			print(2, 5, "mpu type:   %7s", mpu);
 			print(2, 6, "romdata:   %08x", &romdata);
diff --git a/demo/test_bopti.c b/demo/test_bopti.c
index a908823..9b137c8 100644
--- a/demo/test_bopti.c
+++ b/demo/test_bopti.c
@@ -95,14 +95,10 @@ static image_t *select(image_t *current)
 				8 * i, 7, 7);
 			if(i == row)
 			{
-				print(2, 2 + i + 1, "%08x", (unsigned int)
-					images[i].img);
-/*
 				int width, height;
 				getwh(images[i].img, &width, &height);
 				print(2, 2 + i + 1, "%d\x04%d", width, height);
 				locate(10, 2 + i + 1, images[i].info);
-*/
 			}
 		}
 
@@ -147,7 +143,7 @@ void test_bopti(void)
 
 	while(1)
 	{
-		if(img && (img->format & Channel_Light))
+		if(img && (img->format & channel_light))
 		{
 			gray_start();
 			gclear();
diff --git a/demo/test_rtc.c b/demo/test_rtc.c
index 1211aed..4b8fa65 100644
--- a/demo/test_rtc.c
+++ b/demo/test_rtc.c
@@ -14,9 +14,10 @@
 */
 
 #include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <mpu.h>
 
-static void draw(rtc_time_t time)
+static void draw(rtc_time_t *time)
 {
 	extern image_t res_rtc_segments;
 
@@ -30,12 +31,12 @@ static void draw(rtc_time_t time)
 	int digits[6];
 	int i;
 
-	digits[0] = time.hours / 10;
-	digits[1] = time.hours % 10;
-	digits[2] = time.minutes / 10;
-	digits[3] = time.minutes % 10;
-	digits[4] = time.seconds / 10;
-	digits[5] = time.seconds % 10;
+	digits[0] = time->hours / 10;
+	digits[1] = time->hours % 10;
+	digits[2] = time->minutes / 10;
+	digits[3] = time->minutes % 10;
+	digits[4] = time->seconds / 10;
+	digits[5] = time->seconds % 10;
 
 	// Drawing digits.
 	for(i = 0; i < 6; i++) dimage_part(x[i], 8, &res_rtc_segments,
@@ -46,17 +47,18 @@ static void draw(rtc_time_t time)
 
 	// This should print time.year + 1900 but for the sake of this demo we
 	// have tweaked the field so that it already contains time.year + 1900.
-	print(4, 6, "%s %s %02d %4d", days[time.week_day],
-		months[time.month], time.month_day, time.year);
+	print(4, 6, "%s %s %02d %4d", days[time->week_day],
+		months[time->month], time->month_day, time->year);
 }
 
 static void callback(void)
 {
 	extern image_t res_opt_rtc;
-	rtc_time_t time = rtc_getTime();
+	rtc_time_t time;
+	rtc_getTime(&time);
 
 	dclear();
-	draw(time);
+	draw(&time);
 	dimage_part(0, 56, &res_opt_rtc, 0, 0, 19, 8);
 	dupdate();
 }
@@ -128,14 +130,16 @@ static void set(void)
 		{ 72, 39,  7,  9 }, {  84, 39,  7,  9 }, { 90, 39,  7,  9 },
 		{ 96, 39,  7,  9 }, { 102, 39,  7,  9 },
 	};
-	rtc_time_t time = rtc_getTime();
+	rtc_time_t time;
 	int region_count = 14;
 	int n = 0, slide = 0, key, leave;
 
+	rtc_getTime(&time);
+
 	while(1)
 	{
 		dclear();
-		draw(time);
+		draw(&time);
 		drect(regions[n].x, regions[n].y, regions[n].x + regions[n].w
 			- 1, regions[n].y + regions[n].h - 1, color_invert);
 
@@ -157,7 +161,7 @@ static void set(void)
 				slide = 0;
 				if(++n == region_count)
 				{
-					rtc_setTime(time);
+					rtc_setTime(&time);
 					return;
 				}
 			}
@@ -216,7 +220,7 @@ static void set(void)
 					n++;
 					if(n == region_count)
 					{
-						rtc_setTime(time);
+						rtc_setTime(&time);
 						return;
 					}
 					slide = 0;
@@ -235,7 +239,7 @@ void test_rtc(void)
 {
 	int key, cb_id;
 
-	cb_id = rtc_cb_add(RTCFreq_1Hz, callback, 0);
+	cb_id = rtc_cb_add(rtc_freq_1Hz, callback, 0);
 	callback();
 
 	while(1)
@@ -245,10 +249,10 @@ void test_rtc(void)
 		if(key == KEY_EXIT) break;
 		if(key == KEY_F1)
 		{	
-			rtc_cb_edit(cb_id, RTCFreq_None, NULL);
+			rtc_cb_edit(cb_id, rtc_freq_none, NULL);
 			set();
 			callback();
-			rtc_cb_edit(cb_id, RTCFreq_1Hz, callback);
+			rtc_cb_edit(cb_id, rtc_freq_1Hz, callback);
 		}
 	}
 
diff --git a/demo/test_timer.c b/demo/test_timer.c
index d64e6c0..011f365 100644
--- a/demo/test_timer.c
+++ b/demo/test_timer.c
@@ -41,7 +41,7 @@ static void timing_start(void)
 	timer_attach(htimer, timing_timer, NULL);
 	timer_start(htimer);
 
-	rtc_cb_edit(cb_id, RTCFreq_64Hz, timing_rtc);
+	rtc_cb_edit(cb_id, rtc_freq_64Hz, timing_rtc);
 
 	elapsed_timer = 0;
 	elapsed_rtc = 0;
@@ -247,7 +247,7 @@ void test_timer(void)
 
 	elapsed_timer	= -1;
 	elapsed_rtc	= -1;
-	cb_id = rtc_cb_add(RTCFreq_64Hz, timing_start, 0);
+	cb_id = rtc_cb_add(rtc_freq_64Hz, timing_start, 0);
 
 	text_configure(NULL, color_black);
 
diff --git a/include/bopti.h b/include/bopti.h
index 8889359..95465c7 100644
--- a/include/bopti.h
+++ b/include/bopti.h
@@ -46,8 +46,11 @@ void dimage(int x, int y, image_t *image);
 	Point (left, top) is included, but (left + width, top + height) is
 	excluded.
 */
-void dimage_part(int x, int y, image_t *img, int left, int top, int width,
-	int height);
+void dimage_part(
+	int x, int y,
+	image_t *img,
+	int left, int top, int width, int height
+);
 
 /*
 	gimage()
@@ -61,7 +64,10 @@ void gimage(int x, int y, image_t *image);
 	Point (left, top) is included, but (left + width, top + height) is
 	excluded.
 */
-void gimage_part(int x, int y, image_t *image, int left, int top, int width,
-	int height);
+void gimage_part(
+	int x, int y,
+	image_t *image,
+	int left, int top, int width, int height
+);
 
 #endif	// _BOPTI_H
diff --git a/include/gint.h b/include/gint.h
index 887b960..57486a1 100644
--- a/include/gint.h
+++ b/include/gint.h
@@ -15,9 +15,6 @@
 #include <stdint.h>
 #include <stddef.h>
 
-#define	GINT_VERSION		0x000100a3
-#define	GINT_VERSION_STR	"00.01"
-
 //---
 //	System info provided by the library
 //---
diff --git a/include/internals/bopti.h b/include/internals/bopti.h
index 31a87e0..2c93153 100644
--- a/include/internals/bopti.h
+++ b/include/internals/bopti.h
@@ -1,19 +1,3 @@
-//---
-//
-//	gint drawing module: bopti
-//
-//	bopti does every job related to display images. There is only one
-//	public function, but there are lots of internal optimizations.
-//
-//	Some bit-manipulation expressions may look written out of nowhere. The
-//	idea is always the same: get a part of the image in an 'operator',
-//	which is a 32-bit variable, shift this operator so that its bits
-//	correspond to the desired position for the bitmap on the screen, and
-//	edit the video-ram long entry which correspond to this position using
-//	a 'mask' that indicates which bits of the operator contain information.
-//
-//---
-
 #ifndef	_INTERNALS_BOPTI_H
 #define	_INTERNALS_BOPTI_H
 
@@ -21,40 +5,45 @@
 #include <display.h>
 
 /*
-	enum Channel
-	Determines the kind of information written into a layer. Every image is
-	made of one or more channels.
+	channel_t
+	Indicates what operation a layer is made for. Each operation affects
+	the video ram differently (setting or clearing pixels, transparency,
+	etc). An image is made of several layers.
 */
-enum Channel
+typedef enum
 {
-	Channel_FullAlpha	= 0x01,
-	Channel_LightAlpha	= 0x02,
-	Channel_DarkAlpha	= 0x04,
+	channel_full_alpha	= 0x01,
+	channel_light_alpha	= 0x02,
+	channel_dark_alpha	= 0x04,
 
-	Channel_Mono		= 0x08,
-	Channel_Light		= 0x10,
-	Channel_Dark		= 0x20,
-};
+	channel_mono		= 0x08,
+	channel_light		= 0x10,
+	channel_dark		= 0x20,
+
+} channel_t;
 
 /*
-	enum Format
-	Describes the various combination of channels allowed by bopti.
+	format_t
+	Describes the various combination of layer channels that are allowed by
+	bopti. Technically one could try other formats but they're not of much
+	use (transparent gray is even totally useless).
 */
-enum Format
+typedef enum
 {
-	Format_Mono		= Channel_Mono,
-	Format_MonoAlpha	= Format_Mono | Channel_FullAlpha,
-	Format_Gray		= Channel_Light | Channel_Dark,
-	Format_GrayAlpha	= Format_Gray | Channel_FullAlpha,
-	Format_GreaterAlpha	= Format_Mono | Channel_LightAlpha |
-				  Channel_DarkAlpha
-};
+	format_mono		= channel_mono,
+	format_mono_alpha	= format_mono | channel_full_alpha,
+	format_gray		= channel_light | channel_dark,
+	format_gray_alpha	= format_gray | channel_full_alpha,
+	format_greater_alpha	= format_mono | channel_light_alpha |
+				  channel_dark_alpha
+} format_t;
 
 /*
-	struct Structure
-	Describes an image's structure.
+	structure_t
+	Basically an image's dimensions, data pointer, and a few other useful
+	information such as the pitch in bytes.
 */
-struct Structure
+typedef struct
 {
 	int width, height;
 	int layer_size;
@@ -62,26 +51,37 @@ struct Structure
 	const uint8_t *data;
 	int columns;
 	int end_size, end_bytes;
-};
+
+} structure_t;
 
 /*
-	struct Command
-	Contains a drawing operation's parameters.
+	command_t
+	The parameters of a drawing operation. A pointer to such a structure is
+	created by the public functions and passed down to the module's
+	sub-functions during rendering.
 */
-struct Command
+typedef struct command_t
 {
 	// Channel being drawn.
-	enum Channel channel;
+	channel_t channel;
 	// Operation used (whether bopti_op_mono() or bopti_op_gray()).
-	void (*op)(int offset, uint32_t operator, struct Command *command);
+	void (*op)(int offset, uint32_t operator, struct command_t *command);
 	// Portion of the bitmap which is drawn. 'top' and 'bottom' refer to
 	// lines where 'left' and 'right' refer to column ids.
 	int left, right, top, bottom;
 	// Position of the bitmap on the screen.
 	int x, y;
-	// Rectangle masks.
+	// Rectangle masks that define the drawing area.
 	uint32_t masks[4];
-};
+	// Video rams being used.
+	union {
+		// Different names, same fate. (Kingdom Hearts II)
+		uint32_t *vram;
+		uint32_t *v1;
+	};
+	uint32_t *v2;
+
+} command_t;
 
 // The video ram addresses are set by the public functions and used internally
 // by the module.
@@ -91,7 +91,7 @@ extern uint32_t *bopti_vram, *bopti_v1, *bopti_v2;
 
 
 //---
-//	Some bopti routines.
+//	Internal bopti routines.
 //---
 
 /*
@@ -100,11 +100,12 @@ extern uint32_t *bopti_vram, *bopti_v1, *bopti_v2;
 	image information. Since neutral bits are not the same for all
 	operations, a mask is used to indicate which bits should be used for
 	the operation. This mask is taken for the image's rectangle masks (see
-	module display for more information on rectangle masks).
-	Which operation is performed is determined by the channel setting.
+	the 'display' module internal header for more information on rectangle
+	masks). Which operation is performed is determined by the channel
+	setting of the command argument.
 */
-void bopti_op_mono(int offset, uint32_t operator, struct Command *c);
-void bopti_op_gray(int offset, uint32_t operator, struct Command *c);
+void bopti_op_mono(int offset, uint32_t operator, command_t *c);
+void bopti_op_gray(int offset, uint32_t operator, command_t *c);
 
 /*
 	bopti_grid()		-- general form
@@ -115,12 +116,11 @@ void bopti_op_gray(int offset, uint32_t operator, struct Command *c);
 	The need for bopti_grid_a32() is not only linked to optimization,
 	because bopti_grid() will perform a 32-bit shift when x is a multiple
 	of 32, which is undefined behavior.
-	bopti_grid() calls bopti_grid_32() by default.
+	bopti_grid() automatically calls bopti_grid_a32() when required.
 */
 void bopti_grid_a32(const uint32_t *layer, int columns, int height,
-	struct Command *c);
-void bopti_grid(const uint32_t *layer, int columns, int height,
-	struct Command *c);
+	command_t *c);
+void bopti_grid(const uint32_t *layer, int columns, int height, command_t *c);
 /*
 	bopti_end_get()
 	Returns an operator for the end of a line, whose width is lower than 32
@@ -138,23 +138,25 @@ uint32_t bopti_end_get2(const unsigned char **data);
 	Draws the end of a layer, which can be considered as a whole layer
 	whose with is lower than 32. (Actually is it lower or equal to 16;
 	otherwise it would have been a column and the end would be empty). The
-	'size' arguments is in bytes.
+	'size' arguments is in bytes, thus 1 or 2.
 	Unlike bopti_grid_a32(), bopti_end_nover() is not called automatically
 	by bopti_end().
 */
-void bopti_end_nover(const unsigned char *end, int size, struct Command *c);
-void bopti_end(const unsigned char *end, int size, struct Command *c);
+void bopti_end_nover(const unsigned char *end, int size, command_t *c);
+void bopti_end(const unsigned char *end, int size, command_t *c);
 
 /*
 	bopti()
-	Draws a layer in the video ram.
+	Draws a layer's data in the video ram areas specified in the command
+	argument.
 */
-void bopti(const unsigned char *layer, struct Structure *s, struct Command *c);
+void bopti(const unsigned char *layer, structure_t *s, command_t *c);
 
 /*
 	getStructure()
-	Determines the image size and data pointer.
+	Determines the image size (large images have a somehow different
+	structure), the data pointer and a few dimensions inside the image.
 */
-void getStructure(image_t *img, struct Structure *structure);
+void getStructure(image_t *img, structure_t *structure);
 
 #endif	// _INTERNALS_BOPTI_H
diff --git a/include/internals/gint.h b/include/internals/gint.h
index 601ff70..fd51e06 100644
--- a/include/internals/gint.h
+++ b/include/internals/gint.h
@@ -37,7 +37,7 @@ void gint_setvbr(uint32_t vbr, void (*setup)(void));
 
 
 //---
-//	Initialization and termination routines.
+//	Initialization and termination routines, environment saves.
 //---
 
 /*
@@ -53,29 +53,80 @@ void gint_init(void);
 */
 void gint_quit(void);
 
+#include <modules/rtc.h>
+#include <modules/timer.h>
+
+/*
+	environment_t
+	Structure where all registers used by gint are saved by default to
+	ensure that the operating system is not disturbed.
+*/
+typedef struct
+{
+	// Interrupt controller.
+	uint16_t	IPR[8];
+
+	// Real-Time Clock.
+	uint8_t		RCR1, RCR2;
+
+	// Timer Unit.
+	mod_tmu_timer_t	TMU0, TMU1, TMU2;
+	uint8_t		TSTR;
+
+	// I/O ports for the keyboard driver.
+	uint16_t	PACR, PBCR, PMCR;
+	uint8_t		PADR, PBDR, PMDR;
+
+} environment_7705_t;
+
+typedef struct
+{
+	// Interrupt controller.
+	uint16_t	IPR[12];
+
+	// Real-Time Clock.
+	uint8_t		RCR1, RCR2;
+
+	// Timer Unit.
+	mod_tmu_timer_t	TMU0, TMU1, TMU2;
+	uint8_t		TSTR;
+
+	// I/O ports for the keyboard driver.
+	uint16_t	PMCR, PNCR, PZCR;
+	uint8_t		PMDR, PNDR, PZDR;
+	uint8_t		key;
+
+} environment_7305_t;
+
+typedef union
+{
+	environment_7705_t	env_7705;
+	environment_7305_t	env_7305;
+
+} environment_t;
+
 /*
 	gint_save()
-	Saves many registers into a buffer to ensure that the system is not
-	upset by gint's configuration when the application ends.
+	Saves many registers into an internal environment buffer.
 */
-// void gint_save_7705(gint_save_buffer_t *buffer);
-// void gint_save_7305(gint_save_buffer_t *buffer);
+void gint_save_7705(environment_7705_t *env);
+void gint_save_7305(environment_7305_t *env);
 
 /*
-	gint_setup()
-	Configures interrupt priorities and some parameters to allow gint to
-	take control of the interrupt flow.
+	gint_lock_and_setup()
+	Locks all interrupts (ie. disables them by default) and sets initial
+	values to all registers, allows specific interrupts, etc.
 */
-void gint_setup_7705(void);
-void gint_setup_7305(void);
+void gint_lock_and_setup_7705(void);
+void gint_lock_and_setup_7305(void);
 
 /*
-	gint_restore()
-	Restores the parameters saved in a save buffer to give back the
-	interrupt control to the system.
+	gint_restore_and_unlock()
+	Restores the parameters saved in the environment buffer to give back
+	the interrupt control to the system.
 */
-// void gint_restore_7705(gint_save_buffer_t *buffer);
-// void gint_restore_7305(gint_save_buffer_t *buffer);
+void gint_restore_and_unlock_7705(environment_7705_t *env);
+void gint_restore_and_unlock_7305(environment_7305_t *env);
 
 /*
 	gint_reg()
diff --git a/include/internals/keyboard.h b/include/internals/keyboard.h
index 738c1ee..2ed7f9e 100644
--- a/include/internals/keyboard.h
+++ b/include/internals/keyboard.h
@@ -5,11 +5,12 @@
 #include <timer.h>
 #include <clock.h>
 
-// Keyboard variables.
+// Current keyboard state and keyboard interrupt flag.
 extern volatile uint8_t keyboard_state[10];
 extern volatile int interrupt_flag;
 
-// Key statistics.
+// Delays (milliseconds) before repetitions, last key pressed, how many times
+// it has been repeated already, time elapsed since last repetition (ms).
 extern int repeat_first, repeat_next;
 extern int last_key, last_repeats, last_time;
 
diff --git a/include/internals/mmu.h b/include/internals/mmu.h
index ced7211..1fcf6ac 100644
--- a/include/internals/mmu.h
+++ b/include/internals/mmu.h
@@ -3,8 +3,8 @@
 //	gint core module: mmu
 //
 //	A wise application should avoid tampering with the system's
-//	configuration of the MMU and the TLB. This module implicitly calls the
-//	system but does nothing by itself.
+//	configuration of the MMU and the TLB. This module implicitly forces the
+//	system to load the required pages but does not interact with the TLB.
 //
 //---
 
diff --git a/include/internals/rtc.h b/include/internals/rtc.h
index 4f3e348..4b9f9e0 100644
--- a/include/internals/rtc.h
+++ b/include/internals/rtc.h
@@ -9,20 +9,21 @@
 #endif
 
 /*
-	struct rtc_cb
-	An RTC callback.
+	rtc_callback_t
+	An RTC callback with a unique id.
 */
-struct rtc_cb
+typedef struct
 {
 	rtc_frequency_t freq;
 	int id;
 
 	void (*callback)(void);
 	int repeats;
-};
+
+} rtc_callback_t;
 
 // The callback array.
-struct rtc_cb cb_array[RTC_CB_ARRAY_SIZE];
+rtc_callback_t cb_array[RTC_CB_ARRAY_SIZE];
 
 /*
 	rtc_perodic_interrupt()
@@ -37,118 +38,4 @@ void rtc_periodic_interrupt(void);
 */
 void rtc_cb_interrupt(void);
 
-/*
-	struct mod_rtc
-	This structure describes the arrangement of RTC register in the memory.
-	Curious thing, on SH7705, registers RYRAR and RCR3 are at a completely
-	different address than the other ones. This module does not use these
-	registers, so they were not included in the structure.
-*/
-#pragma pack(push, 1)
-
-struct mod_rtc
-{
-	unsigned char const R64CNT;
-	unsigned char _1;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned		:1;
-			unsigned TENS		:3;
-			unsigned ONES		:4;
-		};
-	} RSECCNT;
-	unsigned char _2;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned		:1;
-			unsigned TENS		:3;
-			unsigned ONES		:4;
-		};
-	} RMINCNT;
-	unsigned char _3;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned		:2;
-			unsigned TENS		:2;
-			unsigned ONES		:4;
-		};
-	} RHRCNT;
-	unsigned char _4;
-
-	// 0 = Sunday, 1 = Monday, ..., 6 = Saturday, 7 = prohibited setting.
-	unsigned char RWKCNT;
-	unsigned char _5;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned		:2;
-			unsigned TENS		:2;
-			unsigned ONES		:4;
-		};
-	} RDAYCNT;
-	unsigned char _6;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned		:3;
-			unsigned TENS		:1;
-			unsigned ONES		:4;
-		};
-	} RMONCNT;
-	unsigned char _7;
-
-	union {
-		unsigned short WORD;
-		struct {
-			unsigned THOUSANDS	:4;
-			unsigned HUNDREDS	:4;
-			unsigned TENS		:4;
-			unsigned ONES		:4;
-		};
-	} RYRCNT;
-	unsigned char _8[12];
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned CF		:1;
-			unsigned		:2;
-			unsigned CIE		:1;
-			unsigned AIE		:1;
-			unsigned		:2;
-			unsigned AF		:1;
-		};
-	} RCR1;
-	unsigned char _9;
-
-	union {
-		unsigned char BYTE;
-		struct {
-			unsigned PEF		:1;
-			unsigned PES		:3;
-			unsigned		:1;
-			unsigned ADJ		:1;
-			unsigned RESET		:1;
-			unsigned START		:1;
-		};
-	} RCR2;
-} __attribute__((packed));
-
-#pragma pack(pop)
-
-/*
-	We don't need to access the registers in a complicated way like the
-	function of the timer module. Let's make it simple.
-*/
-#define	RTC_SH7705	((volatile struct mod_rtc *)0xfffffec0)
-#define	RTC_SH7305	((volatile struct mod_rtc *)0xa413fec0)
-
 #endif	// _INTERNALS_RTC_H
diff --git a/include/modules/macros.h b/include/modules/macros.h
index 5f4403b..664fc7d 100644
--- a/include/modules/macros.h
+++ b/include/modules/macros.h
@@ -3,6 +3,15 @@
 
 #include <stdint.h>
 
+// Padding is just empty space, we don't want to give it a name. There's also
+// some subtle preprocessor trick to automatically add a (supposedly) unique
+// name to each padding member. For instance the substitution may operate as:
+//   name(__LINE__) -> namesub(78) -> _##78 -> _78
+#define	namesub(x)	_##x
+#define	name(x)		namesub(x)
+#define	pad(bytes)				\
+	uint8_t name(__LINE__)[bytes]		\
+
 // Fixed-width types for bit field are totally meaningless.
 typedef unsigned uint;
 
diff --git a/include/modules/rtc.h b/include/modules/rtc.h
new file mode 100644
index 0000000..7eb7ef0
--- /dev/null
+++ b/include/modules/rtc.h
@@ -0,0 +1,131 @@
+#ifndef	_MODULES_RTC_H
+#define	_MODULES_RTC_H
+
+#include <modules/macros.h>
+#include <stdint.h>
+
+/*
+	mod_rtc_rcr1_t
+	First RTC configuration register.
+*/
+typedef struct
+{
+	byte_union(,
+		uint	CF	:1;	/* Carry flag */
+		uint		:2;
+		uint	CIE	:1;	/* Carry interrupt enable */
+		uint	AIE	:1;	/* Alarm interrupt enable */
+		uint		:2;
+		uint	AF	:1;	/* Alarm flag */
+	);
+
+} __attribute__((packed)) mod_rtc_rcr1_t;
+
+/*
+	mod_rtc_rcr2_t
+	Second RTC configuration register.
+*/
+typedef struct
+{
+	byte_union(,
+		uint	PEF	:1;	/* Periodic interrupt flag */
+		uint	PES	:3;	/* Periodic interrupt interval */
+		uint		:1;
+		uint	ADJ	:1;	/* 30-second adjustment */
+		uint	RESET	:1;	/* Reset */
+		uint	START	:1;	/* Start bit */
+	);
+
+} __attribute__((packed)) mod_rtc_rcr2_t;
+
+/*
+	mod_rtc_rcr3_t
+	Third RTC configuration register.
+
+typedef struct
+{
+	byte_union(,
+		uint	YAEN	:1;
+		uint		:7;
+	);
+
+} __attribute__((packed)) mod_rtc_rcr3_t;
+*/
+
+/*
+	mod_rtc_time_t
+	A set of registers describing the current time in BCD format.
+*/
+typedef struct
+{
+	const uint8_t	R64CNT;		/* More or less a 64-Hz counter */
+	pad(1);
+
+	byte_union(RSECCNT,		/* Second count */
+		uint		:1;
+		uint	TENS	:3;
+		uint	ONES	:4;
+	);
+	pad(1);
+
+	byte_union(RMINCNT,		/* Minute count */
+		uint		:1;
+		uint	TENS	:3;
+		uint	ONES	:4;
+	);
+	pad(1);
+
+	byte_union(RHRCNT,		/* Hour count */
+		uint		:2;
+		uint	TENS	:2;
+		uint	ONES	:4;
+	);
+	pad(1);
+
+	/* 0 = Sunday .. 6 = Saturday, other settings are prohibited. */
+	uint8_t		RWKCNT;		/* Day of week */
+	pad(1);
+
+	byte_union(RDAYCNT,		/* Day count */
+		uint		:2;
+		uint	TENS	:2;
+		uint	ONES	:4;
+	);
+	pad(1);
+
+	byte_union(RMONCNT,		/* Month count */
+		uint		:3;
+		uint	TENS	:1;
+		uint	ONES	:4;
+	);
+	pad(1);
+
+	word_union(RYRCNT,		/* Year count */
+		uint	THOUSANDS	:4;
+		uint	HUNDREDS	:4;
+		uint	TENS		:4;
+		uint	ONES		:4;
+	);
+
+} __attribute__((packed, aligned(2))) mod_rtc_time_t;
+
+/*
+	mod_rtc_t (resides into gint memory)
+	Three control registers and timer information.
+*/
+typedef struct
+{
+	/* RCR1, RCR2, and RCR3 are the same for both platforms. */
+	volatile mod_rtc_rcr1_t		*RCR1;
+	volatile mod_rtc_rcr2_t		*RCR2;
+//	volatile mod_rtc_rcr3_t		*RCR3;
+	/* Current time in register memory */
+	volatile mod_rtc_time_t		*time;
+
+} mod_rtc_t;
+
+// All you need to use is this structure, initialized by gint, which contains
+// address that work with your execution platform.
+extern mod_rtc_t RTC;
+
+#endif	// _INTERNALS_RTC_H
diff --git a/include/modules/timer.h b/include/modules/timer.h
index 3a8b187..46657ae 100644
--- a/include/modules/timer.h
+++ b/include/modules/timer.h
@@ -59,6 +59,6 @@ typedef struct
 
 // The actual thing is there. It's initialized by gint at startup and contains
 // addresses and information suitable for the current platform.
-extern volatile mod_tmu_t TMU;
+extern mod_tmu_t TMU;
 
 #endif	// _MODULES_TIMER
diff --git a/include/mpu.h b/include/mpu.h
index dd183bc..d3c751f 100644
--- a/include/mpu.h
+++ b/include/mpu.h
@@ -49,7 +49,7 @@ typedef enum
 
 // Global MPU variable, accessible for direct tests. Initialized at the
 // beginning of execution.
-extern mpu_t MPU_CURRENT;
+extern const mpu_t MPU_CURRENT;
 
 // Quick SH3 test. It is safer to assume that an unknown model is SH4 because
 // SH3-based models are not produced anymore.
diff --git a/include/rtc.h b/include/rtc.h
index 771ac2c..2c65876 100644
--- a/include/rtc.h
+++ b/include/rtc.h
@@ -2,7 +2,10 @@
 //
 //	gint core module: rtc
 //
-//	Manages RTC. This module is used behind standard module time.
+//	Manages the Real-Time Clock (RTC). This module provides access to the
+//	current time as well as regular callbacks at predefined frequencies,
+//	more or less like a timer.
+//	The standard time module is built upon this one.
 //
 //---
 
@@ -36,14 +39,14 @@ typedef struct
 	Reads the current time from the RTC. There is no guarantee that the
 	week day is correct (use the time API for that).
 */
-rtc_time_t rtc_getTime(void);
+void rtc_getTime(rtc_time_t *time);
 
 /*
 	rtc_setTime()
 	Sets the time in the RTC registers. The week day is set to 0 if greater
 	than 6. Other fields are not checked.
 */
-void rtc_setTime(rtc_time_t time);
+void rtc_setTime(const rtc_time_t *time);
 
 
 
@@ -58,14 +61,14 @@ void rtc_setTime(rtc_time_t time);
 */
 typedef enum
 {
-	RTCFreq_500mHz	= 7,
-	RTCFreq_1Hz	= 6,
-	RTCFreq_2Hz	= 5,
-	RTCFreq_4Hz	= 4,
-	RTCFreq_16Hz	= 3,
-	RTCFreq_64Hz	= 2,
-	RTCFreq_256Hz	= 1,
-	RTCFreq_None	= 0,
+	rtc_freq_500mHz	= 7,
+	rtc_freq_1Hz	= 6,
+	rtc_freq_2Hz	= 5,
+	rtc_freq_4Hz	= 4,
+	rtc_freq_16Hz	= 3,
+	rtc_freq_64Hz	= 2,
+	rtc_freq_256Hz	= 1,
+	rtc_freq_none	= 0,
 
 } rtc_frequency_t;
 
@@ -94,7 +97,7 @@ void rtc_cb_end(int id);
 	  -1	Callback does not exist
 	  -2	Invalid parameters
 	This function never removes a callback. Call rtc_cb_end() for this. One
-	can set the function to NULL or the frequency to RTCFreq_None to
+	can set the function to NULL or the frequency to rtc_freq_none to
 	temporarily disable the callback.
 */
 int rtc_cb_edit(int id, rtc_frequency_t new_freq, void (*new_function)(void));
diff --git a/src/bopti/bopti_internals.c b/src/bopti/bopti_internals.c
index c42d128..0469e81 100644
--- a/src/bopti/bopti_internals.c
+++ b/src/bopti/bopti_internals.c
@@ -12,17 +12,17 @@ uint32_t *bopti_vram, *bopti_v1, *bopti_v2;
 	module display for more information on rectangle masks).
 	Which operation is performed is determined by the channel setting.
 */
-void bopti_op_mono(int offset, uint32_t operator, struct Command *c)
+void bopti_op_mono(int offset, uint32_t operator, command_t *c)
 {
 	operator &= c->masks[offset & 3];
 
 	switch(c->channel)
 	{
-	case Channel_FullAlpha:
+	case channel_full_alpha:
 		bopti_vram[offset] &= ~operator;
 		break;
 
-	case Channel_Mono:
+	case channel_mono:
 		bopti_vram[offset] |= operator;
 		break;
 
@@ -30,31 +30,31 @@ void bopti_op_mono(int offset, uint32_t operator, struct Command *c)
 		break;
 	}
 }
-void bopti_op_gray(int offset, uint32_t operator, struct Command *c)
+void bopti_op_gray(int offset, uint32_t operator, command_t *c)
 {
 	operator &= c->masks[offset & 3];
 
 	switch(c->channel)
 	{
-	case Channel_FullAlpha:
+	case channel_full_alpha:
 		bopti_v1[offset] &= ~operator;
 		bopti_v2[offset] &= ~operator;
 		break;
 
-	case Channel_LightAlpha:
-	case Channel_DarkAlpha:
+	case channel_light_alpha:
+	case channel_dark_alpha:
 		break;
 
-	case Channel_Mono:
+	case channel_mono:
 		bopti_v1[offset] |= operator;
 		bopti_v2[offset] |= operator;
 		break;
 
-	case Channel_Light:
+	case channel_light:
 		bopti_v1[offset] |= operator;
 		break;
 
-	case Channel_Dark:
+	case channel_dark:
 		bopti_v2[offset] |= operator;
 		break;
 	}
@@ -71,7 +71,7 @@ void bopti_op_gray(int offset, uint32_t operator, struct Command *c)
 	of 32, which is undefined behavior.
 */
 void bopti_grid_a32(const uint32_t *layer, int column_count, int height,
-	struct Command *c)
+	command_t *c)
 {
 	int vram_column_offset = (c->y << 2) + (c->x >> 5);
 	int vram_offset = vram_column_offset;
@@ -91,7 +91,7 @@ void bopti_grid_a32(const uint32_t *layer, int column_count, int height,
 	}
 }
 void bopti_grid(const uint32_t *layer, int column_count, int height,
-	struct Command *c)
+	command_t *c)
 {
 	if(!column_count) return;
 	if(!(c->x & 31))
@@ -177,9 +177,9 @@ uint32_t bopti_end_get2(const unsigned char **data)
 
 	Draws the end of a layer, which can be considered as a whole layer
 	whose with is lower than 32. (Actually is it lower or equal to 16;
-	otherwise it would have been a column and the end would be empty).
+	otherwise it would have been a column and the end would be empty.)
 */
-void bopti_end_nover(const unsigned char *end, int size, struct Command *c)
+void bopti_end_nover(const unsigned char *end, int size, command_t *c)
 {
 	uint32_t (*get)(const unsigned char **data) =
 		(size == 2) ? bopti_end_get2 : bopti_end_get1;
@@ -199,19 +199,17 @@ void bopti_end_nover(const unsigned char *end, int size, struct Command *c)
 	{
 		operator = (*get)(&end);
 		operator <<= shift;
-
-		 (c->op)(vram_offset, operator, c);
-
+		(c->op)(vram_offset, operator, c);
 		vram_offset += 4;
 	}
 }
-void bopti_end(const unsigned char *end, int size, struct Command *c)
+void bopti_end(const unsigned char *end, int size, command_t *c)
 {
 	uint32_t (*get)(const unsigned char **data) =
 		(size == 2) ? (bopti_end_get2) : (bopti_end_get1);
 
 	int vram_offset = (c->y << 2) + (c->x >> 5);
-	uint32_t row_data, operator;
+	uint32_t row_data;
 	int row;
 
 	int shift_base = (32 - (size << 3));
@@ -225,15 +223,8 @@ void bopti_end(const unsigned char *end, int size, struct Command *c)
 	for(row = c->top; row < c->bottom; row++)
 	{
 		row_data = (*get)(&end);
-
-		operator = row_data >> shift1;
-		 (c->op)(vram_offset, operator, c);
-
-
-		operator = row_data << shift2;
-		 (c->op)(vram_offset + 1, operator, c);
-
-
+		(c->op)(vram_offset, row_data >> shift1, c);
+		(c->op)(vram_offset + 1, row_data << shift2, c);
 		vram_offset += 4;
 	}
 }
@@ -248,7 +239,7 @@ void bopti_end(const unsigned char *end, int size, struct Command *c)
 	bopti()
 	Draws a layer in the video ram.
 */
-void bopti(const unsigned char *layer, struct Structure *s, struct Command *c)
+void bopti(const unsigned char *layer, structure_t *s, command_t *c)
 {
 	const unsigned char *grid, *end;
 	int grid_columns, has_end;
@@ -283,9 +274,10 @@ void bopti(const unsigned char *layer, struct Structure *s, struct Command *c)
 
 /*
 	getStructure()
-	Determines the image size and data pointer.
+	Determines the image size (large images have a somehow different
+	structure), the data pointer and a few dimensions inside the image.
 */
-void getStructure(image_t *img, struct Structure *s)
+void getStructure(image_t *img, structure_t *s)
 {
 	int column_count, end, end_bytes, layer;
 
diff --git a/src/bopti/dimage.c b/src/bopti/dimage.c
index 3d05d72..fe34859 100644
--- a/src/bopti/dimage.c
+++ b/src/bopti/dimage.c
@@ -12,12 +12,12 @@ void dimage_part(int x, int y, image_t *img, int left, int top, int width,
 {
 	if(!img || img->magic != 0x01) return;
 
-	struct Structure s;
-	struct Command command;
+	structure_t s;
+	command_t command;
 	int actual_width;
 	int format = img->format, i = 0;
 
-	if(format != Format_Mono && format != Format_MonoAlpha) return;
+	if(format != format_mono && format != format_mono_alpha) return;
 	getStructure(img, &s);
 	if(width < 0) width = s.width;
 	if(height < 0) height = s.height;
diff --git a/src/bopti/gimage.c b/src/bopti/gimage.c
index c6c51c0..e570634 100644
--- a/src/bopti/gimage.c
+++ b/src/bopti/gimage.c
@@ -13,8 +13,8 @@ void gimage_part(int x, int y, image_t *img, int left, int top, int width,
 {
 	if(!img || img->magic != 0x01) return;
 
-	struct Structure s;
-	struct Command command;
+	structure_t s;
+	command_t command;
 	int actual_width;
 	int format = img->format, i = 0;
 
diff --git a/src/clock/clock.c b/src/clock/clock.c
index 9da10f8..8084c4d 100644
--- a/src/clock/clock.c
+++ b/src/clock/clock.c
@@ -143,7 +143,7 @@ void clock_measure(void)
 	{
 		htimer_7705 = htimer_setup(timer_user, 0xffffffff, timer_Po_4,
 			1);
-		cb_id_7705 = rtc_cb_add(RTCFreq_256Hz, clock_measure_7705, 0);
+		cb_id_7705 = rtc_cb_add(rtc_freq_256Hz, clock_measure_7705, 0);
 	}
 
 	// On SH7305, assuming clock mode 3, we can compute the clock
@@ -268,5 +268,5 @@ static void clock_measure_7705_callback(void)
 static void clock_measure_7705(void)
 {
 	timer_start(htimer_7705);
-	rtc_cb_edit(cb_id_7705, RTCFreq_256Hz, clock_measure_7705_callback);
+	rtc_cb_edit(cb_id_7705, rtc_freq_256Hz, clock_measure_7705_callback);
 }
diff --git a/src/core/crt0.c b/src/core/crt0.c
index a343a98..c00aeb9 100644
--- a/src/core/crt0.c
+++ b/src/core/crt0.c
@@ -20,7 +20,7 @@ extern uint32_t
 	etext, btext,		// Location of .text section
 	bdata, edata,		// Location of .data section
 	bbss, ebss,		// Location of .bss section
-	bgint, egint,		// Location of interrut handler and gint data
+	bgint, egint,		// Location of interrupt handler and gint data
 	gint_vbr,		// VBR address
 	romdata;		// ROM address of .data section contents
 
@@ -45,7 +45,7 @@ __attribute__((section(".pretext.entry"))) int start(void)
 {
 	#ifdef	GINT_DIAGNOSTICS
 
-	// Ok, so fill as much information as possible so that in case anything
+	// OK, so fill as much information as possible so that in case anything
 	// goes wrong we can try to analyze what's been going on.
 	volatile gint_diagnostics_t *dg = gint_diagnostics();
 
@@ -77,7 +77,7 @@ __attribute__((section(".pretext.entry"))) int start(void)
 	dg->section_data.length		= (uint32_t)&edata - (uint32_t)&bdata;
 	dg->section_bss.address		= (uint32_t)&bbss;
 	dg->section_bss.length		= (uint32_t)&ebss  - (uint32_t)&bbss;
-	dg->romdata	= (uint32_t)&romdata;
+	dg->romdata			= (uint32_t)&romdata;
 
 	// Basic information about the running library.
 	dg->vbr_address			= (uint32_t)&gint_vbr;
@@ -108,10 +108,11 @@ __attribute__((section(".pretext.entry"))) int start(void)
 	dg->stage	= stage_mmu;
 	#endif
 
-	// Detecting the MPU type, initializing the register module addresses,
-	// and initializing gint.
-	mpu_init();
-	mod_init();
+	// Initializing gint, which does several things:
+	//   - Detect the MPU and platform
+	//   - Initialize register addresses in a platform-independent way
+	//   - Save the current environment information in a large buffer
+	//   - Set up the interrupt handler and configure everything gint needs
 	gint_init();
 
 	#ifdef	GINT_DIAGNOSTICS
@@ -148,16 +149,15 @@ __attribute__((section(".pretext.entry"))) int start(void)
 	if(!x) exit_code = main();
 
 
+
 	#ifdef	GINT_DIAGNOSTICS
 	dg->stage	= stage_leaving;
 	#endif
 
 	/* TODO Flush and close opened streams. */
 
-	// Calling exit handlers.
+	// Calling exit handlers and destructors.
 	while(atexit_index > 0) (*atexit_handlers[--atexit_index])();
-
-	// Calling the destructors.
 	fini();
 
 	#ifdef	GINT_DIAGNOSTICS
diff --git a/src/core/exceptions.c b/src/core/exceptions.c
index 9491221..ad2ac4a 100644
--- a/src/core/exceptions.c
+++ b/src/core/exceptions.c
@@ -33,8 +33,8 @@ static void show_error(const char *name, uint32_t *access_mode, uint32_t *tea,
 {
 	uint32_t *vram = display_getCurrentVRAM();
 	uint32_t spc, ssr;
-	__asm__("stc spc, %0" : "=rm"(spc));
-	__asm__("stc ssr, %0" : "=rm"(ssr));
+	__asm__("stc spc, %0" : "=r"(spc));
+	__asm__("stc ssr, %0" : "=r"(ssr));
 
 	dclear();
 	text_configure(NULL, color_black);
diff --git a/src/core/gint.c b/src/core/gint.c
index 608bce5..6d309f9 100644
--- a/src/core/gint.c
+++ b/src/core/gint.c
@@ -1,12 +1,3 @@
-//---
-//
-//	gint core module: interrupt handler
-//
-//	Central point of the library. Controls the interrupt handler and
-//	defines a few functions to configure callbacks for some interrupts.
-//
-//---
-
 #include <internals/gint.h>
 #include <internals/interrupt_maps.h>
 #include <internals/exceptions.h>
@@ -110,10 +101,10 @@ void gint_invoke(uint8_t type, uint8_t subtype)
 	uint16_t *pc;
 
 	// Getting some initial information to work with.
-	__asm__("stc spc, %0" : "=rm"(pc));
+	__asm__("stc spc, %0" : "=r"(pc));
 	tea = gint_reg(register_tea);
 	tra = gint_reg(register_tra);
-	tcpr_2 = (void *)0xfffffeb8;
+	tcpr_2 = (void *)0xfffffeb8;	/* SH7705 only */
 
 	// Building up the argument list.
 	for(int i = 0; i < 3; i++) switch(gint_handlers[type].args[i])
diff --git a/src/core/gint_sh7305.c b/src/core/gint_sh7305.c
index 7410084..9c54118 100644
--- a/src/core/gint_sh7305.c
+++ b/src/core/gint_sh7305.c
@@ -1,15 +1,6 @@
-//---
-//
-//	gint core module: sh7305 interrupt handler
-//
-//	Of course all the work related to interrupts is heavily platform-
-//	dependent. This module handles interrupts and configures the MPU to
-//	save and restore the system's configuration when execution ends.
-//
-//---
-
 #include <internals/gint.h>
-#include <internals/rtc.h>
+#include <modules/timer.h>
+#include <modules/rtc.h>
 #include <gint.h>
 #include <timer.h>
 #include <7305.h>
@@ -38,108 +29,108 @@ volatile void *gint_reg_7305(gint_register_t reg)
 
 
 //---
-//	Setup.
+//	Register saves, setup, interrupt locks, register restoration.
 //---
 
-static unsigned short ipr[12];
-static unsigned char rcr2;
-// Saves of the keyboard registers. Could be better.
-static unsigned short inj1, inj2, det;
-static unsigned char data1, data2, keys, reg;
-
-static void gint_priority_lock_7305(void)
+void gint_save_7305(environment_7305_t *e)
 {
-	// Saving the current interrupt priorities.
-	ipr[0]  = INTX.IPRA.WORD;
-	ipr[1]  = INTX.IPRB.WORD;
-	ipr[2]  = INTX.IPRC.WORD;
-	ipr[3]  = INTX.IPRD.WORD;
-	ipr[4]  = INTX.IPRE.WORD;
-	ipr[5]  = INTX.IPRF.WORD;
-	ipr[6]  = INTX.IPRG.WORD;
-	ipr[7]  = INTX.IPRH.WORD;
-	ipr[8]  = INTX.IPRI.WORD;
-	ipr[9]  = INTX.IPRJ.WORD;
-	ipr[10] = INTX.IPRK.WORD;
-	ipr[11] = INTX.IPRL.WORD;
+	// Saving interrupt priorities.
+	e->IPR[0]	= INTX.IPRA.WORD;
+	e->IPR[1]	= INTX.IPRB.WORD;
+	e->IPR[2]	= INTX.IPRC.WORD;
+	e->IPR[3]	= INTX.IPRD.WORD;
+	e->IPR[4]	= INTX.IPRE.WORD;
+	e->IPR[5]	= INTX.IPRF.WORD;
+	e->IPR[6]	= INTX.IPRG.WORD;
+	e->IPR[7]	= INTX.IPRH.WORD;
+	e->IPR[8]	= INTX.IPRI.WORD;
+	e->IPR[9]	= INTX.IPRJ.WORD;
+	e->IPR[10]	= INTX.IPRK.WORD;
+	e->IPR[11]	= INTX.IPRL.WORD;
 
+	// Saving RTC registers.
+	e->RCR1		= RTC.RCR1->byte;
+	e->RCR2		= RTC.RCR2->byte;
+
+	// Saving TMU registers.
+	e->TMU0		= *(TMU.timers[0]);
+	e->TMU1		= *(TMU.timers[1]);
+	e->TMU2		= *(TMU.timers[2]);
+	e->TSTR		= TMU.TSTR->byte;
+
+	// Saving port data used to access the keyboard.
+	e->PMCR		= *((volatile uint16_t *)0xa4050116);
+	e->PMDR		= *((volatile uint8_t  *)0xa4050136);
+	e->PNCR		= *((volatile uint16_t *)0xa4050118);
+	e->PNDR		= *((volatile uint8_t  *)0xa4050138);
+	e->PZCR		= *((volatile uint16_t *)0xa405014c);
+	e->PZDR		= *((volatile uint8_t  *)0xa405016c);
+	e->key		= *((volatile uint8_t  *)0xa40501c6);
+}
+
+void gint_lock_and_setup_7305(void)
+{
 	// Disabling everything by default to avoid freezing on non-handled
 	// interrupts.
-	INTX.IPRA.WORD = 0x0000;
-	INTX.IPRB.WORD = 0x0000;
-	INTX.IPRC.WORD = 0x0000;
-	INTX.IPRD.WORD = 0x0000;
-	INTX.IPRE.WORD = 0x0000;
-	INTX.IPRF.WORD = 0x0000;
-	INTX.IPRG.WORD = 0x0000;
-	INTX.IPRH.WORD = 0x0000;
-	INTX.IPRI.WORD = 0x0000;
-	INTX.IPRJ.WORD = 0x0000;
-	INTX.IPRK.WORD = 0x0000;
-	INTX.IPRL.WORD = 0x0000;
+	INTX.IPRA.WORD		= 0x0000;
+	INTX.IPRB.WORD		= 0x0000;
+	INTX.IPRC.WORD		= 0x0000;
+	INTX.IPRD.WORD		= 0x0000;
+	INTX.IPRE.WORD		= 0x0000;
+	INTX.IPRF.WORD		= 0x0000;
+	INTX.IPRG.WORD		= 0x0000;
+	INTX.IPRH.WORD		= 0x0000;
+	INTX.IPRI.WORD		= 0x0000;
+	INTX.IPRJ.WORD		= 0x0000;
+	INTX.IPRK.WORD		= 0x0000;
+	INTX.IPRL.WORD		= 0x0000;
 
-	// Saving keyboard registers.
-	inj1	= *((volatile unsigned short *)0xa4050116);
-	data1	= *((volatile unsigned char  *)0xa4050136);
-	inj2	= *((volatile unsigned short *)0xa4050118);
-	data2	= *((volatile unsigned char  *)0xa4050138);
-	det	= *((volatile unsigned short *)0xa405014c);
-	keys	= *((volatile unsigned char  *)0xa405016c);
-	reg	= *((volatile unsigned char  *)0xa40501c6);
-
-	// Allowing RTC. Keyboard analysis is done regularly using a RTC
-	// because SH7305's special KEYSC interface does not allow us to clear
-	// the keyboard interrupt flags.
+	// Allowing RTC and timer to schedule automatic tasks such as keyboard
+	// analysis.
 	INTX.IPRK._RTC		= 10;
 	INTX.IPRA.TMU0_0	= 12;
 	INTX.IPRA.TMU0_1	= 12;
 	INTX.IPRA.TMU0_2	= 12;
+
+	// Don't enable the RTC interrupt by default.
+	RTC.RCR2->byte = 0x09;
 }
 
-static void gint_priority_unlock_7305(void)
+void gint_restore_and_unlock_7305(environment_7305_t *e)
 {
 	// Restoring the interrupt priorities.
-	INTX.IPRA.WORD = ipr[0];
-	INTX.IPRB.WORD = ipr[1];
-	INTX.IPRC.WORD = ipr[2];
-	INTX.IPRD.WORD = ipr[3];
-	INTX.IPRE.WORD = ipr[4];
-	INTX.IPRF.WORD = ipr[5];
-	INTX.IPRG.WORD = ipr[6];
-	INTX.IPRH.WORD = ipr[7];
-	INTX.IPRI.WORD = ipr[8];
-	INTX.IPRJ.WORD = ipr[9];
-	INTX.IPRK.WORD = ipr[10];
-	INTX.IPRL.WORD = ipr[11];
+	INTX.IPRA.WORD		= e->IPR[0];
+	INTX.IPRB.WORD		= e->IPR[1];
+	INTX.IPRC.WORD		= e->IPR[2];
+	INTX.IPRD.WORD		= e->IPR[3];
+	INTX.IPRE.WORD		= e->IPR[4];
+	INTX.IPRF.WORD		= e->IPR[5];
+	INTX.IPRG.WORD		= e->IPR[6];
+	INTX.IPRH.WORD		= e->IPR[7];
+	INTX.IPRI.WORD		= e->IPR[8];
+	INTX.IPRJ.WORD		= e->IPR[9];
+	INTX.IPRK.WORD		= e->IPR[10];
+	INTX.IPRL.WORD		= e->IPR[11];
 
-	// Restoring keyboard registers.
-	*((volatile unsigned short *)0xa4050116) = inj1;
-	*((volatile unsigned char  *)0xa4050136) = data1;
-	*((volatile unsigned short *)0xa4050118) = inj2;
-	*((volatile unsigned char  *)0xa4050138) = data2;
-	*((volatile unsigned short *)0xa405014c) = det;
-	*((volatile unsigned char  *)0xa405016c) = keys;
-	*((volatile unsigned char  *)0xa40501c6) = reg;
-}
-
-void gint_setup_7305(void)
-{
-	volatile struct mod_rtc *RTC = RTC_SH7305;
-
-	gint_priority_lock_7305();
-
-	// Saving the RTC configuration.
-	rcr2 = RTC->RCR2.BYTE;
-	// Disabling RTC interrupts by default.
-	RTC->RCR2.BYTE = 0x09;
-}
-
-void gint_stop_7305(void)
-{
-	volatile struct mod_rtc *RTC = RTC_SH7305;
-
-	gint_priority_unlock_7305();
-
-	// Restoring the RTC configuration.
-	RTC->RCR2.BYTE = rcr2;
+	// Restoring RTC registers.
+	RTC.RCR1->byte		= e->RCR1;
+	RTC.RCR2->byte		= e->RCR2;
+
+	// Restoring TMU registers.
+	*(TMU.timers[0])	= e->TMU0;
+	*(TMU.timers[1])	= e->TMU1;
+	*(TMU.timers[2])	= e->TMU2;
+	TMU.TSTR->byte		= e->TSTR;
+
+	// Restoring keyboard-related I/O port registers. However the backlight
+	// pin is in PNDR and we would like the backlight to persist when we
+	// leave the application, so we just keep this bit.
+	*((volatile uint16_t *)0xa4050116)	= e->PMCR;
+	*((volatile uint8_t  *)0xa4050136)	= e->PMDR;
+	*((volatile uint16_t *)0xa4050118)	= e->PNCR;
+	*((volatile uint8_t  *)0xa4050138)	&= 0x10;
+	*((volatile uint8_t  *)0xa4050138)	|= (e->PNDR & ~0x10);
+	*((volatile uint16_t *)0xa405014c)	= e->PZCR;
+	*((volatile uint8_t  *)0xa405016c)	= e->PZDR;
+	*((volatile uint8_t  *)0xa40501c6)	= e->key;
 }
diff --git a/src/core/gint_sh7705.c b/src/core/gint_sh7705.c
index 9f5ac26..d19924d 100644
--- a/src/core/gint_sh7705.c
+++ b/src/core/gint_sh7705.c
@@ -1,15 +1,5 @@
-//---
-//
-//	gint core module: sh7705 interrupt handler
-//
-//	Of course all the work related to interrupts is heavily platform-
-//	dependent. This module handles interrupts and configures the MPU to
-//	save and restore the system's configuration when execution ends.
-//
-//---
-
 #include <internals/gint.h>
-#include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <gint.h>
 #include <timer.h>
 #include <7705.h>
@@ -38,74 +28,92 @@ volatile void *gint_reg_7705(gint_register_t reg)
 
 
 //---
-//	Setup.
+//	Register saves, setup, interrupt locks, register restoration.
 //---
 
-static unsigned short iprs[8];
-static unsigned char rcr2;
-
-static void gint_priority_lock_7705(void)
+void gint_save_7705(environment_7705_t *e)
 {
 	// Saving the interrupt masks from registers IPRA to IPRH.
-	iprs[0] = INTC.IPRA.WORD;
-	iprs[1] = INTC.IPRB.WORD;
-	iprs[2] = INTX.IPRC.WORD;
-	iprs[3] = INTX.IPRD.WORD;
-	iprs[4] = INTX.IPRE.WORD;
-	iprs[5] = INTX.IPRF.WORD;
-	iprs[6] = INTX.IPRG.WORD;
-	iprs[7] = INTX.IPRH.WORD;
+	e->IPR[0] = INTC.IPRA.WORD;
+	e->IPR[1] = INTC.IPRB.WORD;
+	e->IPR[2] = INTX.IPRC.WORD;
+	e->IPR[3] = INTX.IPRD.WORD;
+	e->IPR[4] = INTX.IPRE.WORD;
+	e->IPR[5] = INTX.IPRF.WORD;
+	e->IPR[6] = INTX.IPRG.WORD;
+	e->IPR[7] = INTX.IPRH.WORD;
 
+	// Saving RTC registers.
+	e->RCR1		= RTC.RCR1->byte;
+	e->RCR2		= RTC.RCR2->byte;
+
+	// Saving TMU registers.
+	e->TMU0		= *(TMU.timers[0]);
+	e->TMU1		= *(TMU.timers[1]);
+	e->TMU2		= *(TMU.timers[2]);
+	e->TSTR		= TMU.TSTR->byte;
+
+	// Saving port data used to access the keyboard.
+	e->PACR	 	= PFC.PACR.WORD;
+	e->PADR	 	= PA.DR.BYTE;
+	e->PBCR	 	= PFC.PBCR.WORD;
+	e->PBDR	 	= PB.DR.BYTE;
+	e->PMCR	 	= PFC.PMCR.WORD;
+	e->PMDR	 	= PM.DR.BYTE;
+}
+
+void gint_lock_and_setup_7705(void)
+{
 	// Disabling everything by default to avoid receiving an interrupt that
 	// the handler doesn't handle, which would cause the user program to
 	// freeze.
-	INTC.IPRA.WORD = 0x0000;
-	INTC.IPRB.WORD = 0x0000;
-	INTX.IPRC.WORD = 0x0000;
-	INTX.IPRD.WORD = 0x0000;
-	INTX.IPRE.WORD = 0x0000;
-	INTX.IPRF.WORD = 0x0000;
-	INTX.IPRG.WORD = 0x0000;
-	INTX.IPRH.WORD = 0x0000;
+	INTC.IPRA.WORD		= 0x0000;
+	INTC.IPRB.WORD		= 0x0000;
+	INTX.IPRC.WORD		= 0x0000;
+	INTX.IPRD.WORD		= 0x0000;
+	INTX.IPRE.WORD		= 0x0000;
+	INTX.IPRF.WORD		= 0x0000;
+	INTX.IPRG.WORD		= 0x0000;
+	INTX.IPRH.WORD		= 0x0000;
 
-	// Allowing RTC, which handles keyboard.
+	// Allowing RTC and timer (which handles keyboard and a whole bunch of
+	// other things).
 	INTC.IPRA.BIT._RTC	= 10;
 	INTC.IPRA.BIT._TMU0	= 12;
 	INTC.IPRA.BIT._TMU1	= 12;
 	INTC.IPRA.BIT._TMU2	= 12;
+
+	// Don't enable RTC periodic signals by default.
+	RTC.RCR2->byte		= 0x09;
 }
 
-static void gint_priority_unlock_7705(void)
+void gint_restore_and_unlock_7705(environment_7705_t *e)
 {
 	// Restoring the saved states.
-	INTC.IPRA.WORD = iprs[0];
-	INTC.IPRB.WORD = iprs[1];
-	INTX.IPRC.WORD = iprs[2];
-	INTX.IPRD.WORD = iprs[3];
-	INTX.IPRE.WORD = iprs[4];
-	INTX.IPRF.WORD = iprs[5];
-	INTX.IPRG.WORD = iprs[6];
-	INTX.IPRH.WORD = iprs[7];
-}
-
-void gint_setup_7705(void)
-{
-	volatile struct mod_rtc *RTC = RTC_SH7705;
-
-	gint_priority_lock_7705();
-
-	// Saving the RTC configuration.
-	rcr2 = RTC->RCR2.BYTE;
-	// Disabling RTC interrupts by default.
-	RTC->RCR2.BYTE = 0x09;
-}
-
-void gint_stop_7705(void)
-{
-	volatile struct mod_rtc *RTC = RTC_SH7705;
-
-	gint_priority_unlock_7705();
-
-	// Restoring the RTC configuration.
-	RTC->RCR2.BYTE = rcr2;
+	INTC.IPRA.WORD		= e->IPR[0];
+	INTC.IPRB.WORD		= e->IPR[1];
+	INTX.IPRC.WORD		= e->IPR[2];
+	INTX.IPRD.WORD		= e->IPR[3];
+	INTX.IPRE.WORD		= e->IPR[4];
+	INTX.IPRF.WORD		= e->IPR[5];
+	INTX.IPRG.WORD		= e->IPR[6];
+	INTX.IPRH.WORD		= e->IPR[7];
+
+	// Restoring RTC registers.
+	RTC.RCR1->byte		= e->RCR1;
+	RTC.RCR2->byte		= e->RCR2;
+
+	// Restoring TMU registers.
+	*(TMU.timers[0])	= e->TMU0;
+	*(TMU.timers[1])	= e->TMU1;
+	*(TMU.timers[2])	= e->TMU2;
+	TMU.TSTR->byte		= e->TSTR;
+
+	// Restoring keyboard-related I/O port registers.
+	PFC.PACR.WORD		= e->PACR;
+	PA.DR.BYTE		= e->PADR;
+	PFC.PBCR.WORD		= e->PBCR;
+	PB.DR.BYTE		= e->PBDR;
+	PFC.PMCR.WORD		= e->PMCR;
+	PM.DR.BYTE		= e->PMDR;
 }
diff --git a/src/core/gint_vbr.s b/src/core/gint_vbr.s
index 7253a91..067aadb 100644
--- a/src/core/gint_vbr.s
+++ b/src/core/gint_vbr.s
@@ -49,7 +49,7 @@ _gint_setvbr:
 	jsr	@r5
 	nop
 
-	/* Activating interrupts again. */
+	/* Enabling interrupts again. */
 	mov.l	sr_block, r0
 	not	r0, r0
 	stc	sr, r3
diff --git a/src/core/init_quit.c b/src/core/init_quit.c
index ac16dd0..a50d287 100644
--- a/src/core/init_quit.c
+++ b/src/core/init_quit.c
@@ -1,9 +1,11 @@
 #include <internals/gint.h>
 #include <internals/interrupt_maps.h>
+#include <internals/modules.h>
 #include <gint.h>
 #include <mpu.h>
 
 gint_info_t gint;
+static environment_t env;
 
 //---
 //	Initialization routines
@@ -16,10 +18,17 @@ gint_info_t gint;
 */
 static void setup(void)
 {
-	isSH3() ? gint_setup_7705() : gint_setup_7305();
+	isSH3()	? gint_lock_and_setup_7705()
+		: gint_lock_and_setup_7305();
 }
 void gint_init(void)
 {
+	// Detecting the MPU type. I don't like const-casting but this is still
+	// better than allowing the user to change the variable by mistake.
+	*((mpu_t *)&MPU_CURRENT) = getMPU();
+	// Loading the register addresses of the current platform.
+	mod_init();
+
 	// Linker script symbols -- gint.
 	extern uint32_t
 		gint_vbr,
@@ -32,6 +41,9 @@ void gint_init(void)
 	// Loading the interrupt handler into the memory.
 	while(ptr < &egint) *ptr++ = *src++;
 
+	isSH3()	? gint_save_7705(&env.env_7705)
+		: gint_save_7305(&env.env_7305);
+
 	// Installing gint's default exception/interrupt handlers.
 	for(int i = 0; i < exc_type_max; i++)
 	{
@@ -59,7 +71,8 @@ void gint_init(void)
 */
 static void stop(void)
 {
-	isSH3() ? gint_stop_7705() : gint_stop_7305();
+	isSH3()	? gint_restore_and_unlock_7705(&env.env_7705)
+		: gint_restore_and_unlock_7305(&env.env_7305);
 }
 void gint_quit(void)
 {
diff --git a/src/core/modules.c b/src/core/modules.c
index aad3491..60cc146 100644
--- a/src/core/modules.c
+++ b/src/core/modules.c
@@ -1,4 +1,6 @@
 #include <modules/timer.h>
+#include <modules/rtc.h>
+
 #include <stddef.h>
 #include <mpu.h>
 
@@ -11,7 +13,8 @@
 //	confront to the hardware directly.
 //---
 
-volatile mod_tmu_t TMU;
+mod_tmu_t	TMU;
+mod_rtc_t	RTC;
 
 
 
@@ -26,6 +29,10 @@ static void mod_init_7705(void)
 	TMU.timers[2]	= (void *)0xfffffeac;
 	TMU.TSTR	= (void *)0xfffffe92;
 	TMU.TCPR2	= (void *)0xfffffeb8;
+
+	RTC.RCR1	= (void *)0xfffffedc;
+	RTC.RCR2	= (void *)0xfffffede;
+	RTC.time	= (void *)0xfffffec0;
 }
 
 static void mod_init_7305(void)
@@ -35,6 +42,10 @@ static void mod_init_7305(void)
 	TMU.timers[2]	= (void *)0xa4490020;
 	TMU.TSTR	= (void *)0xa4490004;
 	TMU.TCPR2	= NULL;
+
+	RTC.RCR1	= (void *)0xa413fedc;
+	RTC.RCR2	= (void *)0xa413fede;
+	RTC.time	= (void *)0xa413fec0;
 }
 
 /*
diff --git a/src/core/mpu.c b/src/core/mpu.c
index 13f621c..a952e67 100644
--- a/src/core/mpu.c
+++ b/src/core/mpu.c
@@ -8,7 +8,7 @@
 
 #include <mpu.h>
 
-mpu_t MPU_CURRENT;
+const mpu_t MPU_CURRENT;
 
 /*
 	getMPU()
@@ -67,14 +67,3 @@ mpu_t getMPU(void)
 	// By default, the MPU is unknown.
 	return mpu_unknown;
 }
-
-
-
-/*
-	mpu_init()
-	Determines the MPU type and stores the result into MPU_CURRENT.
-*/
-__attribute__((constructor)) void mpu_init(void)
-{
-	MPU_CURRENT = getMPU();
-}
diff --git a/src/keyboard/keyboard_sh7305.c b/src/keyboard/keyboard_sh7305.c
index cae413a..68e1fc8 100644
--- a/src/keyboard/keyboard_sh7305.c
+++ b/src/keyboard/keyboard_sh7305.c
@@ -30,6 +30,8 @@
 	many keys on the same column are pressed, other keys of the same column
 	may be triggered.
 
+	(The following values do not apply to the latest tests, even if the
+	trend remains the same.)
 	- Less	Bad key detection.
 	- 8	Very few column effects. Most often, three keys may be pressed
 		simultaneously. However, [UP] has latencies and is globally not
@@ -49,7 +51,8 @@ static void kdelay(void)
 
 	__asm__
 	(
-		"nop\n\t"
+		r4(r4("nop\n\t"))
+		r4(r4("nop\n\t"))
 	);
 
 	#undef	r4
diff --git a/src/rtc/rtc_callback.c b/src/rtc/rtc_callback.c
index 488d0ce..1efeb24 100644
--- a/src/rtc/rtc_callback.c
+++ b/src/rtc/rtc_callback.c
@@ -1,13 +1,14 @@
 #include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <rtc.h>
 #include <mpu.h>
 
 // Array holding callback informations.
-struct rtc_cb cb_array[RTC_CB_ARRAY_SIZE] = { 0 };
+rtc_callback_t cb_array[RTC_CB_ARRAY_SIZE] = { 0 };
 // Callback identifier (unique).
 static int unique_id = 1;
 // Current RTC interrupt frequency.
-static rtc_frequency_t rtc_freq = RTCFreq_None;
+static rtc_frequency_t rtc_freq = rtc_freq_none;
 // 256-Hz tick count. This counter is stopped when no callback is registered.
 static unsigned elapsed256 = 0;
 
@@ -21,7 +22,7 @@ static unsigned elapsed256 = 0;
 */
 static void rtc_cb_update(void)
 {
-	rtc_frequency_t max = RTCFreq_None;
+	rtc_frequency_t max = rtc_freq_none;
 	int n;
 
 	for(n = 0; n < RTC_CB_ARRAY_SIZE; n++) if(cb_array[n].id)
@@ -33,8 +34,7 @@ static void rtc_cb_update(void)
 	if(rtc_freq == max) return;
 	rtc_freq = max;
 
-	volatile struct mod_rtc *RTC = isSH3() ? RTC_SH7705 : RTC_SH7305;
-	RTC->RCR2.BYTE = (rtc_freq << 4) | 0x09;
+	RTC.RCR2->byte = (rtc_freq << 4) | 0x09;
 }
 
 /*
@@ -49,7 +49,7 @@ static void rtc_cb_update(void)
 int rtc_cb_add(rtc_frequency_t freq, void (*function)(void), int repeats)
 {
 	int n = 0;
-	if(freq == RTCFreq_None || !function || repeats < 0) return -2;
+	if(freq == rtc_freq_none || !function || repeats < 0) return -2;
 
 	while(n < RTC_CB_ARRAY_SIZE && cb_array[n].id) n++;
 	if(n >= RTC_CB_ARRAY_SIZE) return -1;
@@ -77,7 +77,7 @@ void rtc_cb_end(int id)
 	if(n >= RTC_CB_ARRAY_SIZE) return;
 
 	cb_array[n].id		= 0;
-	cb_array[n].freq	= RTCFreq_None;
+	cb_array[n].freq	= rtc_freq_none;
 	cb_array[n].callback	= NULL;
 	cb_array[n].repeats	= 0;
 
@@ -134,7 +134,7 @@ void rtc_cb_interrupt(void)
 
 	for(n = 0; n < RTC_CB_ARRAY_SIZE; n++)
 	{
-		struct rtc_cb *cb = &cb_array[n];
+		rtc_callback_t *cb = &cb_array[n];
 		if(!cb->id || !cb->freq) continue;
 
 		// Only execute callback when the number of elapsed 256-Hz
diff --git a/src/rtc/rtc_getTime.c b/src/rtc/rtc_getTime.c
index 5a460e9..dab7074 100644
--- a/src/rtc/rtc_getTime.c
+++ b/src/rtc/rtc_getTime.c
@@ -1,16 +1,17 @@
 #include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <rtc.h>
 #include <mpu.h>
 
 /*
-	integer()
+	integer8(), integer16() [static]
 	Converts a BCD value to an integer.
 */
-static int integer8(int bcd)
+static int integer8(uint8_t bcd)
 {
 	return (bcd & 0x0f) + 10 * (bcd >> 4);
 }
-static int integer16(int bcd)
+static int integer16(uint16_t bcd)
 {
 	return (bcd & 0xf) + 10 * ((bcd >> 4) & 0xf) + 100 * ((bcd >> 8) & 0xf)
 		+ 1000 * (bcd >> 12);
@@ -19,26 +20,23 @@ static int integer16(int bcd)
 /*
 	rtc_getTime()
 	Reads the current time from the RTC. There is no guarantee that the
-	week day is correct (use the time API for that).
+	week day will contain a correct value (use the time API for that).
 */
-rtc_time_t rtc_getTime(void)
+void rtc_getTime(rtc_time_t *time)
 {
-	volatile struct mod_rtc *rtc = isSH3() ? RTC_SH7705 : RTC_SH7305;
-	rtc_time_t time;
+	if(!time) return;
 
 	do
 	{
-		rtc->RCR1.CF = 0;
+		RTC.RCR1->CF = 0;
 
-		time.seconds	= integer8(rtc->RSECCNT.BYTE);
-		time.minutes	= integer8(rtc->RMINCNT.BYTE);
-		time.hours	= integer8(rtc->RHRCNT.BYTE);
-		time.month_day	= integer8(rtc->RDAYCNT.BYTE);
-		time.month	= integer8(rtc->RMONCNT.BYTE);
-		time.year	= integer16(rtc->RYRCNT.WORD);
-		time.week_day	= rtc->RWKCNT;
+		time->seconds	= integer8(RTC.time->RSECCNT.byte);
+		time->minutes	= integer8(RTC.time->RMINCNT.byte);
+		time->hours	= integer8(RTC.time->RHRCNT .byte);
+		time->month_day	= integer8(RTC.time->RDAYCNT.byte);
+		time->month	= integer8(RTC.time->RMONCNT.byte);
+		time->year	= integer16(RTC.time->RYRCNT.word);
+		time->week_day	= RTC.time->RWKCNT;
 	}
-	while(rtc->RCR1.CF != 0);
-
-	return time;
+	while(RTC.RCR1->CF != 0);
 }
diff --git a/src/rtc/rtc_interrupt.c b/src/rtc/rtc_interrupt.c
index 32a2c73..c3e0df6 100644
--- a/src/rtc/rtc_interrupt.c
+++ b/src/rtc/rtc_interrupt.c
@@ -1,9 +1,8 @@
 #include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <rtc.h>
 #include <mpu.h>
 
-int rtc_carry_flag = 0;
-
 /*
 	rtc_periodic_interrupt()
 	Handles an RTC interrupt by calling the callback.
@@ -12,6 +11,5 @@ void rtc_periodic_interrupt(void)
 {
 	rtc_cb_interrupt();
 
-	volatile struct mod_rtc *RTC = isSH3() ? RTC_SH7705 : RTC_SH7305;
-	RTC->RCR2.PEF = 0;
+	RTC.RCR2->PEF = 0;
 }
diff --git a/src/rtc/rtc_setTime.c b/src/rtc/rtc_setTime.c
index 4e71e7f..27c8a3a 100644
--- a/src/rtc/rtc_setTime.c
+++ b/src/rtc/rtc_setTime.c
@@ -1,17 +1,18 @@
 #include <internals/rtc.h>
+#include <modules/rtc.h>
 #include <rtc.h>
 #include <mpu.h>
 
 /*
-	bcd()
+	bcd8(), bcd16() [static]
 	Converts an integer to a BCD value.
 */
-static int bcd8(int integer)
+static uint8_t bcd8(int integer)
 {
 	integer %= 100;
 	return ((integer / 10) << 4) | (integer % 10);
 }
-static int bcd16(int integer)
+static uint16_t bcd16(int integer)
 {
 	integer %= 10000;
 	return (bcd8(integer / 100) << 8) | bcd8(integer % 100);
@@ -22,22 +23,22 @@ static int bcd16(int integer)
 	Sets the time in the RTC registers. The week day is set to 0 if greater
 	than 6. Other fields are not checked.
 */
-void rtc_setTime(rtc_time_t time)
+void rtc_setTime(const rtc_time_t *time)
 {
-	volatile struct mod_rtc *rtc = isSH3() ? RTC_SH7705 : RTC_SH7305;
-	int wday = (time.week_day < 7) ? (time.week_day) : (0);
+	if(!time) return;
+	int wday = (time->week_day < 7) ? (time->week_day) : (0);
 
 	do
 	{
-		rtc->RCR1.CF = 0;
+		RTC.RCR1->CF = 0;
 
-		rtc->RSECCNT.BYTE	= bcd8(time.seconds);
-		rtc->RMINCNT.BYTE	= bcd8(time.minutes);
-		rtc->RHRCNT.BYTE	= bcd8(time.hours);
-		rtc->RDAYCNT.BYTE	= bcd8(time.month_day);
-		rtc->RMONCNT.BYTE	= bcd8(time.month);
-		rtc->RYRCNT.WORD	= bcd16(time.year);
-		rtc->RWKCNT		= wday;
+		RTC.time->RSECCNT.byte	= bcd8(time->seconds);
+		RTC.time->RMINCNT.byte	= bcd8(time->minutes);
+		RTC.time->RHRCNT .byte	= bcd8(time->hours);
+		RTC.time->RDAYCNT.byte	= bcd8(time->month_day);
+		RTC.time->RMONCNT.byte	= bcd8(time->month);
+		RTC.time->RYRCNT .word	= bcd16(time->year);
+		RTC.time->RWKCNT	= wday;
 	}
-	while(rtc->RCR1.CF != 0);
+	while(RTC.RCR1->CF != 0);
 }
diff --git a/src/time/time.c b/src/time/time.c
index e6a6727..e3edd16 100644
--- a/src/time/time.c
+++ b/src/time/time.c
@@ -12,10 +12,11 @@
 */
 time_t time(time_t *timeptr)
 {
-	rtc_time_t rtc = rtc_getTime();
+	rtc_time_t rtc;
 	struct tm tm;
 	time_t calendar;
 
+	rtc_getTime(&rtc);
 	tm.tm_sec	= rtc.seconds;
 	tm.tm_min	= rtc.minutes;
 	tm.tm_hour	= rtc.hours;
diff --git a/version b/version
new file mode 100644
index 0000000..91cef21
--- /dev/null
+++ b/version
@@ -0,0 +1 @@
+beta-0.9-289