bg

.gitignore

@@ -5,4 +5,5 @@ __pycache__
 *.elf
 *.bin
 *.nds
-.~lock*
+.~lock*
+*.csv

Makefile

@@ -1,9 +1,19 @@
+OPT = -Os
+
 all: main.nds
 
+res/%.h: res/%.data
+	$(BUILD_BINARY_H)
+
+res/%.pal.h: res/%.data.pal
+	$(BUILD_BINARY_H)
+
 MAIN_OBJ = \
 	header.o \
 	start.o \
-	main.o
+	main.o \
+	res/player.data.o \
+	res/player.data.pal.o
 
 main.elf: $(MAIN_OBJ)
 

addresses_arm9.lds

@@ -1,4 +1,4 @@
 io_registers = 0x04000000;
 pram = 0x05000000;
-vram = 0x06000000;
 oam = 0x07000000;
+bg_vram = 0x06000000;

arm9.lds

@@ -9,14 +9,19 @@ SECTIONS
 {
   . = ORIGIN(rom);
 
-  .text.header ALIGN(4) : SUBALIGN(4)
+  .text.header ALIGN(4) :
   {
     KEEP(*(.text.header))
   } > rom
 
   . = ORIGIN(ram);
 
-  .text.arm9 ALIGN(4) : SUBALIGN(4)
+  .text.arm7 ALIGN(4) :
+  {
+    KEEP(*(.text.7start))
+  } > ram AT> rom
+
+  .text ALIGN(4) :
   {
     KEEP(*(.text.9start))
     *(.text)
@@ -27,12 +32,6 @@ SECTIONS
     *(.v4_bx)
   } > ram AT> rom
 
-  .text ALIGN(4) : SUBALIGN(4)
-  {
-    *(.text.*)
-    *(.text)
-  } > ram AT> rom
-
   .data ALIGN(4) :
   {
     *(.data)
@@ -45,24 +44,19 @@ SECTIONS
     *(.rodata.*)
   } > ram AT> rom
 
-  .ctors ALIGN(4) : SUBALIGN(4)
+  .ctors ALIGN(4) :
   {
     KEEP(*(.ctors))
     KEEP(*(.ctors.*))
   } > ram AT> rom
 
-  .bss ALIGN(4) (NOLOAD) : SUBALIGN(4)
+  .bss ALIGN(4) (NOLOAD) :
   {
     *(.bss)
     *(.bss.*)
     *(COMMON)
   } > ram AT> rom
 
-  .text.arm7 ALIGN(4) : SUBALIGN(4)
-  {
-    KEEP(*(.text.7start))
-  } > ram AT> rom
-
   INCLUDE "debug.lds"
 }
 

bg.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#include <stdint.h>
+
+#define static_assert _Static_assert
+
+union screen_block {
+  uint8_t u8[0x800 / 1];
+  uint16_t u16[0x800 / 2];
+  uint32_t u32[0x800 / 4];
+};
+static_assert((sizeof (union screen_block)) == 0x800);
+
+struct screen_offset {
+  union screen_block block[32];
+};
+static_assert((sizeof (struct screen_offset)) == 0x10000);
+
+struct screen_data {
+  struct screen_offset offset[8];
+};
+static_assert((sizeof (struct screen_data)) == 0x80000);
+
+union character_block {
+  uint16_t u8[0x4000 / 2];
+  uint16_t u16[0x4000 / 2];
+  uint32_t u32[0x4000 / 4];
+};
+static_assert((sizeof (union character_block)) == 0x4000);
+
+struct character_offset {
+  union character_block block[4]; // is actually 16
+};
+
+struct character_data {
+  struct character_offset offset[8];
+};
+static_assert((sizeof (struct character_data)) == 0x80000);
+
+struct bg {
+  union {
+    struct screen_data screen;
+    struct character_data character;
+  };
+};
+static_assert((sizeof (struct bg)) == 0x80000);
+
+struct bg_vram {
+  struct bg a;
+  uint8_t _pad[0x200000 - (sizeof (struct bg))];
+  struct bg b;
+};
+static_assert((offsetof (struct bg_vram, a)) == 0);
+static_assert((offsetof (struct bg_vram, b)) == 0x200000);
+
+extern struct bg_vram bg_vram __asm("bg_vram");

bits.h

@@ -39,8 +39,8 @@
 #define DISPCNT__bitmap_obj_mapping_mode__1d_mapping (0x2 << 5)
 #define DISPCNT__character_obj_mapping_mode__2d_mapping (0x0 << 4)
 #define DISPCNT__character_obj_mapping_mode__1d_mapping (0x1 << 4)
-#define DISPCNT__2d_3d_display_selection_for_bg0__display_2d_graphics (0x0 << 3)
-#define DISPCNT__2d_3d_display_selection_for_bg0__display_3d_graphics (0x1 << 3)
+#define DISPCNT__display_selection_for_bg0__2d_graphics (0x0 << 3)
+#define DISPCNT__display_selection_for_bg0__3d_graphics (0x1 << 3)
 #define DISPCNT__bg_mode__text0_text1_text2_text3 (0x0 << 0)
 #define DISPCNT__bg_mode__text0_text1_text2_affine3 (0x1 << 0)
 #define DISPCNT__bg_mode__text0_text1_affine2_affine3 (0x2 << 0)
@@ -129,3 +129,9 @@
 #define OBJ_ATTRIBUTE_0__affine_transformation__disable (0x0 << 8)
 #define OBJ_ATTRIBUTE_0__affine_transformation__enable (0x1 << 8)
 #define OBJ_ATTRIBUTE_0__y_coordinate(v) (((v) & 0xff) << 0)
+#define OBJ_ATTRIBUTE_1__obj_size(v) (((v) & 0x3) << 14)
+#define OBJ_ATTRIBUTE_1__affine_transformation_parameter(v) (((v) & 0x1f) << 9)
+#define OBJ_ATTRIBUTE_1__x_coordinate(v) (((v) & 0x1ff) << 0)
+#define OBJ_ATTRIBUTE_2__color_parameter(v) (((v) & 0xf) << 12)
+#define OBJ_ATTRIBUTE_2__display_priority(v) (((v) & 0x3) << 10)
+#define OBJ_ATTRIBUTE_2__character_name(v) (((v) & 0x3ff) << 0)

common.mk

@@ -14,8 +14,8 @@ CFLAGS += -Wno-error=unused-variable
 
 CXXFLAGS += -fno-exceptions -fno-non-call-exceptions -fno-rtti -fno-threadsafe-statics
 
-# --print-gc-sections
-LDFLAGS += --gc-sections --no-warn-rwx-segment --print-memory-usage --entry=_start --orphan-handling=error
+#
+LDFLAGS += --gc-sections --no-warn-rwx-segment --print-memory-usage --entry=_start --orphan-handling=error --print-gc-sections
 
 DEPFLAGS = -MMD -MP
 
@@ -40,7 +40,7 @@ as_obj_binary = _binary_$(subst .,_,$(subst /,_,$(1)))
 define BUILD_BINARY_H
 	@echo gen $@
 	@echo '#pragma once' > $@
-	@echo '#include <cstdint>' >> $@
+	@echo '#include <stdint.h>' >> $@
 	@echo 'extern uint32_t $(call as_obj_binary,$<)_start __asm("$(call as_obj_binary,$<)_start");' >> $@
 	@echo 'extern uint32_t $(call as_obj_binary,$<)_end __asm("$(call as_obj_binary,$<)_end");' >> $@
 	@echo 'extern uint32_t $(call as_obj_binary,$<)_size __asm("$(call as_obj_binary,$<)_size");' >> $@

main.c

@@ -1,9 +1,84 @@
 #include "io_registers.h"
+#include "bits.h"
+#include "bg.h"
+
+#include "res/player.h"
+#include "res/player.pal.h"
+
+static inline uint16_t rgb555(const uint8_t * buf)
+{
+  uint8_t r = buf[0] >> 3;
+  uint8_t g = buf[1] >> 3;
+  uint8_t b = buf[2] >> 3;
+
+  return (b << 10) | (g << 5) | (r << 0);
+}
 
 void main()
 {
-  io_registers.a.DISPCNT = (1 << 16); // DISPLAY_ON
+  io_registers.a.VRAMCNT = (1 << 31) | (1 << 24);
+  io_registers.a.WVRAMCNT = 0;
+
+  io_registers.a.DISPCNT = 0
+    | DISPCNT__bg_screen_base_offset(0)
+    | DISPCNT__bg_character_base_offset(0)
+    | DISPCNT__display_mode__graphics_display
+    | DISPCNT__bg0__enable
+    | DISPCNT__display_selection_for_bg0__2d_graphics
+    | DISPCNT__bg_mode__text0_text1_text2_text3
+    ;
+
+  io_registers.a.BG0CNT = 0
+    | BG0CNT__screen_size__256x256
+    | BG0CNT__screen_base_block(31)
+    | BG0CNT__color_mode__16_color_mode
+    | BG0CNT__character_base_block(0)
+    | BG0CNT__priority(0)
+    ;
+
+  uint32_t pal_size = (uint32_t)&_binary_res_player_data_pal_size;
+  const uint8_t * pal = (const uint8_t *)&_binary_res_player_data_pal_start;
 
   // palette ram
-  *((volatile uint16_t *)(0x05000000)) = (7 << 10) | (31 << 5) | (19 << 0);
+  for (int i = 0; i < 15; i++) {
+    ((volatile uint16_t *)(0x05000000))[i] = rgb555(&pal[i * 3]);
+  }
+
+
+  const uint8_t * data = (const uint8_t *)&_binary_res_player_data_start;
+
+
+
+  for (int y = 0; y < 48; y++) {
+    uint8_t a = data[y * 8 + 0];
+    uint8_t b = data[y * 8 + 1];
+    uint8_t c = data[y * 8 + 2];
+    uint8_t d = data[y * 8 + 3];
+    uint8_t e = data[y * 8 + 4];
+    uint8_t f = data[y * 8 + 5];
+    uint8_t g = data[y * 8 + 6];
+    uint8_t h = data[y * 8 + 7];
+
+    bg_vram.a.character.offset[0].block[0].u32[y] = 0
+      | (a << 28)
+      | (b << 24)
+      | (c << 20)
+      | (d << 16)
+      | (e << 12)
+      | (f << 8)
+      | (g << 4)
+      | (h << 0);
+  }
+
+  for (int i = 0; i < 32 * 32; i++) {
+    bg_vram.a.screen.offset[0].block[31].u16[i] = 30;
+  }
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 0] = 3;
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 1] = 4;
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 2] = 5;
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 0 + 1] = 0;
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 1 + 1] = 1;
+  bg_vram.a.screen.offset[0].block[31].u16[32 * 2 + 1] = 2;
+
+  while (1);
 }

res/player.h

@@ -0,0 +1,5 @@
+#pragma once
+#include <stdint.h>
+extern uint32_t _binary_res_player_data_start __asm("_binary_res_player_data_start");
+extern uint32_t _binary_res_player_data_end __asm("_binary_res_player_data_end");
+extern uint32_t _binary_res_player_data_size __asm("_binary_res_player_data_size");

res/player.pal.h

@@ -0,0 +1,5 @@
+#pragma once
+#include <stdint.h>
+extern uint32_t _binary_res_player_data_pal_start __asm("_binary_res_player_data_pal_start");
+extern uint32_t _binary_res_player_data_pal_end __asm("_binary_res_player_data_pal_end");
+extern uint32_t _binary_res_player_data_pal_size __asm("_binary_res_player_data_pal_size");

symbols.lds

@@ -19,15 +19,15 @@ __bss_link_start = ADDR(.bss);
 __bss_link_end = ADDR(.bss) + SIZEOF(.bss);
 
 /* header symbols */
-_arm9_offset = LOADADDR(.text.arm9);
-_arm9_entry = ADDR(.text.arm9);
-_arm9_addr = ADDR(.text.arm9);
-_arm9_size = SIZEOF(.text.arm9);
+_arm9_offset = LOADADDR(.text);
+_arm9_entry = ADDR(.text);
+_arm9_addr = ADDR(.text);
+_arm9_size = SIZEOF(.text) + SIZEOF(.data) + SIZEOF(.rodata) + SIZEOF(.ctors);
 
 _arm7_offset = LOADADDR(.text.arm7);
 _arm7_entry = ADDR(.text.arm7);
 _arm7_addr = ADDR(.text.arm7);
 _arm7_size = SIZEOF(.text.arm7);
 
-_rom_size = SIZEOF(.text.header) + SIZEOF(.text.arm9) + SIZEOF(.text.arm7);
+_rom_size = SIZEOF(.text.header) + SIZEOF(.text) + SIZEOF(.data) + SIZEOF(.rodata) + SIZEOF(.ctors) + SIZEOF(.text.arm7);
 _header_size = SIZEOF(.text.header);