crash.c

#include "global.h"
#include "main.h"
#include "sound.h"
#include "songs.h"
#include "task.h"
#include "sprite.h"
#include "palette.h"
#include "menu.h"
#include "string_util.h"

extern void WaitForVBlank(void);

extern u8 gUnknown_0839F63C[];
extern u8 gUnknown_0839F5FC[];  //palette

// exceptions
enum
{
	TASK_OVERFLOW
};

struct CrashExceptionInfo
{
	u8 *string;
};

struct CrashScreen
{
    u32 registers[13]; // r0-r12
    void (* returnPointer)(void); // lr
    u32 *stackPointer; // sp
    u32 statusRegister;
    u8 exception;
};

const u8 gCrashScreenHeaderText[] = _("An error has occured. Please pass these\ndetails below to the developers:");
const u8 gCrashScreenRegisterR0[] = _("r0: ");
const u8 gCrashScreenRegisterR1[] = _("r1: ");
const u8 gCrashScreenRegisterR2[] = _("r2: ");
const u8 gCrashScreenRegisterR3[] = _("r3: ");
const u8 gCrashScreenRegisterR4[] = _("r4: ");
const u8 gCrashScreenRegisterR5[] = _("r5: ");
const u8 gCrashScreenRegisterR6[] = _("r6: ");
const u8 gCrashScreenRegisterR7[] = _("r7: ");
const u8 gCrashScreenRegisterR8[] = _("r8: ");
const u8 gCrashScreenRegisterR9[] = _("r9: ");
const u8 gCrashScreenRegisterR10[] = _("r10: ");
const u8 gCrashScreenRegisterR11[] = _("r11: ");
const u8 gCrashScreenRegisterR12[] = _("r12: ");
const u8 gCrashScreenRegisterLR[] = _("lr: ");

const u8 gCrashScreenPlaceholderText[] = _("{STR_VAR_1}");

const u8 gCrashScreenExceptionTaskOverflow[] = _("TASK OVERFLOW");

EWRAM_DATA u32 CrashException = {0};
EWRAM_DATA struct CrashScreen gCrashScreenInfo = {0};

void DoCrashScreen(void);

/*static void MainCB(void)
{
    RunTasks();
    AnimateSprites();
    BuildOamBuffer();
    UpdatePaletteFade();
}*/

// copy the registers and current information to the struct.
__attribute__((naked))
void Crash(void)
{
    asm(".syntax unified\n\
	push {lr}\n\
	mov lr, r12\n\
	push {lr}\n\
	mov lr, r11\n\
	push {lr}\n\
	mov lr, r10\n\
	push {lr}\n\
	mov lr, r9\n\
	push {lr}\n\
	mov lr, r8\n\
	push {r0-r7, lr}\n\
	pop {r0}\n\
	ldr r1, CrashPool\n\
	str r0, [r1]\n\
	ldr r0, CrashPool\n\
	pop {r1}\n\
	str r1, [r0, #0x4]\n\
	pop {r1}\n\
	str r1, [r0, #0x8]\n\
	pop {r1}\n\
	str r1, [r0, #0xC]\n\
	pop {r1}\n\
	str r1, [r0, #0x10]\n\
	pop {r1}\n\
	str r1, [r0, #0x14]\n\
	pop {r1}\n\
	str r1, [r0, #0x18]\n\
	pop {r1}\n\
	str r1, [r0, #0x1C]\n\
	pop {r1}\n\
	str r1, [r0, #0x20]\n\
	pop {r1}\n\
	str r1, [r0, #0x24]\n\
	pop {r1}\n\
	str r1, [r0, #0x28]\n\
	pop {r1}\n\
	str r1, [r0, #0x2C]\n\
	pop {r1}\n\
	str r1, [r0, #0x30]\n\
	pop {r1}\n\
	str r1, [r0, #0x34]\n\
	mov r1, sp\n\
	str r1, [r0, #0x38] @ the stack pointer is equal to its state from the previous function after the push/pops used to preserve the registers and lr.\n\
.align 2\n\
	bx pc @ switch to ARM\n\
	nop @ it takes 1 cycle to switch.\n\
.arm\n\
	mscr r1, cpsr\n\
	str r1, [r0, #0x3C]\n\
	bl DoCrashScreen\n\
	.align 2, 0\n\
CrashPool: .4byte gCrashScreenInfo\n\
	.syntax divided");
}

#define WIN_RANGE_(a, b) (((a) << 8) + (b))

void DoCrashScreen(void)
{
	gCrashScreenInfo.exception = CrashException;

	PlayBGM(BGM_STOP);
	{
	u8 *addr;
	u32 size;

	addr = (u8 *)VRAM;
    size = 0x18000;
    while (1)
    {
        DmaFill16(3, 0, addr, 0x1000);
        addr += 0x1000;
        size -= 0x1000;
        if (size <= 0x1000)
        {
            DmaFill16(3, 0, addr, size);
            break;
        }
    }
    DmaClear32(3, OAM, OAM_SIZE);
    DmaClear16(3, PLTT, PLTT_SIZE);
	ResetPaletteFade();
	SetUpWindowConfig(&gWindowConfig_81E71B4);
	MultistepInitMenuWindowBegin(&gWindowConfig_81E71B4);
	while(!MultistepInitMenuWindowContinue()) // don't return!
		;
	LoadPalette(gUnknown_0839F5FC, 0x80, 0x40);
    CpuCopy16(gUnknown_0839F63C, (void *)0x0600BEE0, 0x40);
	}
	MenuDrawTextWindow(0, 0, 29, 19);
	MenuPrint(gCrashScreenHeaderText, 1, 1);
	MenuPrint(gCrashScreenRegisterR0, 1, 5);
	MenuPrint(gCrashScreenRegisterR1, 1, 7);
	MenuPrint(gCrashScreenRegisterR2, 1, 9);
	MenuPrint(gCrashScreenRegisterR3, 1, 11);
	MenuPrint(gCrashScreenRegisterR4, 1, 13);
	MenuPrint(gCrashScreenRegisterR5, 1, 15);
	MenuPrint(gCrashScreenRegisterR6, 1, 17);

	// print r0.
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[0], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 5);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[1], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 7);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[2], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 9);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[3], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 11);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[4], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 13);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[5], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 15);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[6], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 4, 17);

	MenuPrint(gCrashScreenRegisterR7, 11, 5);
	MenuPrint(gCrashScreenRegisterR8, 11, 7);
	MenuPrint(gCrashScreenRegisterR9, 11, 9);
	MenuPrint(gCrashScreenRegisterR10, 11, 11);
	MenuPrint(gCrashScreenRegisterR11, 11, 13);
	MenuPrint(gCrashScreenRegisterR12, 11, 15);
	MenuPrint(gCrashScreenRegisterLR, 11, 17);

	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[7], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 5);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[8], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 7);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[9], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 9);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[10], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 11);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[11], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 13);
	ConvertIntToHexStringN(gStringVar1, gCrashScreenInfo.registers[12], STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 15);
	ConvertIntToHexStringN(gStringVar1, (u32)gCrashScreenInfo.returnPointer, STR_CONV_MODE_LEADING_ZEROS, 8);
	MenuPrint(gCrashScreenPlaceholderText, 14, 17);

	REG_WIN1H = WIN_RANGE(0, 240);
    REG_WIN1V = WIN_RANGE_(0, 240);
	while(1)
	{
		WaitForVBlank();
	}
}