diff --git a/include/mem_map.h b/include/mem_map.h
index f9f35b8..2885dc1 100644
--- a/include/mem_map.h
+++ b/include/mem_map.h
@@ -107,8 +107,8 @@
 #define	A9_STUB_SIZE         (0x200)
 #define A9_HEAP_END          (A9_RAM_BASE + A9_RAM_SIZE)
 #define A9_STACK_START       (DTCM_BASE)
-#define A9_STACK_END         (DTCM_BASE + DTCM_SIZE - 0x1000)
-#define A9_IRQ_STACK_START   (DTCM_BASE + DTCM_SIZE - 0x1000)
+#define A9_STACK_END         (DTCM_BASE + DTCM_SIZE - 0x800)
+#define A9_IRQ_STACK_START   (DTCM_BASE + DTCM_SIZE - 0x800)
 #define A9_IRQ_STACK_END     (DTCM_BASE + DTCM_SIZE)
 #define A9_EXC_STACK_START   (ITCM_KERNEL_MIRROR + (ITCM_SIZE / 2))
 #define A9_EXC_STACK_END     (ITCM_KERNEL_MIRROR + ITCM_SIZE)
diff --git a/source/arm9/debug.c b/source/arm9/debug.c
index 1fb3a5e..839d921 100644
--- a/source/arm9/debug.c
+++ b/source/arm9/debug.c
@@ -62,11 +62,10 @@
 }
 
 // Expects the registers in the exception stack to be in the following order:
-// cpsr, pc (unmodified), r0-r14
-noreturn void guruMeditation(u8 type, u32 *excStack)
+// r0-r14, pc (unmodified), cpsr
+noreturn void guruMeditation(u8 type, const u32 *excStack)
 {
-	const char *typeStr[3] = {"Undefined instruction", "Prefetch abort", "Data abort"};
-	const size_t maxStackWords = 15 * 2;
+	const char *const typeStr[3] = {"Undefined instruction", "Prefetch abort", "Data abort"};
 	u32 realPc, instSize = 4;
 	bool codeChanged = false;
 
@@ -79,9 +78,9 @@
 
 	consoleInit(0, NULL, true);
 
-	if(excStack[0] & 0x20) instSize = 2; // Processor was in Thumb mode?
-	if(type == 2) realPc = excStack[1] - (instSize * 2); // Data abort
-	else realPc = excStack[1] - instSize; // Other
+	if(excStack[16] & 0x20) instSize = 2; // Processor was in Thumb mode?
+	if(type == 2) realPc = excStack[15] - (instSize * 2); // Data abort
+	else realPc = excStack[15] - instSize; // Other
 
 	printf("\x1b[41m\x1b[0J\x1b[9CGuru Meditation Error!\n\n%s:\n", typeStr[type]);
 	printf("CPSR: 0x%08" PRIX32 "\n"
@@ -93,26 +92,29 @@
 	       "r5 = 0x%08" PRIX32 " sp  = 0x%08" PRIX32 "\n"
 	       "r6 = 0x%08" PRIX32 " lr  = 0x%08" PRIX32 "\n"
 	       "r7 = 0x%08" PRIX32 " pc  = 0x%08" PRIX32 "\n\n",
-	       excStack[0],
+	       excStack[16],
+	       excStack[0], excStack[8],
+	       excStack[1], excStack[9],
 	       excStack[2], excStack[10],
 	       excStack[3], excStack[11],
 	       excStack[4], excStack[12],
 	       excStack[5], excStack[13],
 	       excStack[6], excStack[14],
-	       excStack[7], excStack[15],
-	       excStack[8], excStack[16],
-	       excStack[9], realPc);
+	       excStack[7], realPc);
 
-	// make sure we can actually dump the stack without triggering another fault.
-	if((excStack[15] >= (u32)A9_STACK_START) && (excStack[15] < (u32)A9_STACK_END) &&
-	   (excStack[15] + maxStackWords * 4 < (u32)A9_STACK_END))
+	puts("Stack dump:");
+
+	u32 sp = excStack[13];
+	if(sp >= DTCM_BASE && sp < DTCM_BASE + DTCM_SIZE && !(sp & 3u))
 	{
-		puts("Stack dump:");
-		for(u32 i = 0; i < maxStackWords / 2; i++)
+		u32 stackWords = ((DTCM_BASE + DTCM_SIZE - sp) / 4 > 45 ? 45 : (DTCM_BASE + DTCM_SIZE - sp) / 4);
+
+		u32 newlineCounter = 0;
+		for(u32 i = 0; i < stackWords; i++)
 		{
-			printf("0x%08" PRIX32 ": %08" PRIX32 " %08" PRIX32 "\n", excStack[15],
-			       ((u32*)excStack[15])[0], ((u32*)excStack[15])[1]);
-			excStack[15] += 8;
+			if(newlineCounter == 3) {printf("\n"); newlineCounter = 0;}
+			printf("0x%08" PRIX32 " ", ((u32*)sp)[i]);
+			newlineCounter++;
 		}
 	}
 
@@ -124,7 +126,7 @@
 
 	PXI_sendWord(PXI_CMD_ALLOW_POWER_OFF);
 
-	for(;;) waitForIrq();
+	while(1) waitForIrq();
 }
 
 void dumpMem(u8 *mem, u32 size, char *filepath)
diff --git a/source/arm9/exception.s b/source/arm9/exception.s
index 6d2b894..7b815e9 100644
--- a/source/arm9/exception.s
+++ b/source/arm9/exception.s
@@ -20,19 +20,29 @@
 ASM_FUNC dataAbortHandler
 	msr cpsr_f, #(2<<29)
 ASM_FUNC exceptionHandler
-	mov sp, #A9_EXC_STACK_END
-	stmfd sp!, {r0-r14}^        @ Save all user/system mode regs except pc
-	mrs r4, cpsr
-	lsr r4, r4, #29             @ Get back the exception type from cpsr
-	mrs r1, spsr                @ Get saved cpsr
-	stmfd sp!, {r1, lr}         @ Save spsr and lr (pc) on exception stack
+	sub sp, #68
+	stmia sp, {r0-r14}^            @ Save all user/system mode regs except pc
+	mrs r2, spsr                   @ Get saved cpsr
+	mrs r3, cpsr
+	lsr r0, r3, #29                @ Get back the exception type from cpsr
+	and r1, r2, #0x1F
+	cmp r1, #0x10                  @ User mode
+	beq exceptionHandler_skip_other_mode
+	add r4, sp, #32
+	msr cpsr_c, r2
+	stmia r4!, {r8-r14}            @ Some regs are written twice but we don't care
+	msr cpsr_c, r3
+exceptionHandler_skip_other_mode:
+	str lr, [sp, #60]              @ Save lr (pc) on exception stack
+	str r2, [sp, #64]              @ Save spsr (cpsr) on exception stack
+	mov r4, r0
 	mov r5, sp
-	msr cpsr_cxsf, #0xDF        @ Disable all interrupts, system mode
+	msr cpsr, #0xDF                @ Disable all interrupts, system mode
 	bl deinitCpu
 	mov r0, r4
 	mov sp, r5
 	mov r1, r5
-	b guruMeditation            @ r0 = exception type, r1 = reg dump ptr {cpsr, pc (unmodified), r0-r14}
+	b guruMeditation               @ r0 = exception type, r1 = reg dump ptr {r0-r14, pc (unmodified), cpsr}
 
 
 ASM_FUNC irqHandler
@@ -50,7 +60,15 @@
 	rsb r2, r0, #31             @ r2 = 31 - r0
 	ldr r1, =irqHandlerTable
 	ldr r0, [r1, r2, lsl #2]
+	mrs r2, spsr
+	str r2, [sp, #-4]!
+	msr cpsr_c, #0x5F           @ Interrupts enabled, system mode
+	str lr, [sp, #-4]!
 	cmp r0, #0
 	blxne r0
+	ldr lr, [sp], #4
+	msr cpsr_c, #0xD2           @ Interrupts disabled, IRQ mode
+	ldr r2, [sp], #4
+	msr spsr, r2
 	ldmfd sp!, {r0-r3, r12, lr}
 	subs pc, lr, #4
diff --git a/source/arm9/main.c b/source/arm9/main.c
index 93ee530..f49858a 100644
--- a/source/arm9/main.c
+++ b/source/arm9/main.c
@@ -101,7 +101,7 @@
 	enter_menu(MENU_STATE_MAIN);
 
 	
-finish_firmlaunch:	
+finish_firmlaunch:
 
 	uiPrintIfVerbose("Unmounting FS...\n");
 
diff --git a/source/arm9/start.s b/source/arm9/start.s
index 33dc39d..11e83a6 100644
--- a/source/arm9/start.s
+++ b/source/arm9/start.s
@@ -38,7 +38,7 @@
 	.word   (VERS_MAJOR<<16 | VERS_MINOR)
 
 _start:
-	msr cpsr_cxsf, #0xD3         @ Disable all interrupts, SVC mode
+	msr cpsr, #0xD3              @ Disable all interrupts, SVC mode
 
 	@ Control register:
 	@ [19] ITCM load mode         : disabled
@@ -63,9 +63,13 @@
 	bl setupExceptionVectors    @ Setup the vectors in ARM9 mem bootrom vectors jump to
 
 	mov sp, #0                  @ SVC mode sp (Unused, aborts)
-	msr cpsr_cxsf, #0xD2        @ IRQ mode
+	msr cpsr, #0xD7             @ Abort mode
+	mov sp, #A9_EXC_STACK_END
+	msr cpsr, #0xDB             @ Undefined mode
+	mov sp, #A9_EXC_STACK_END
+	msr cpsr, #0xD2             @ IRQ mode
 	ldr sp, =A9_IRQ_STACK_END
-	msr cpsr_cxsf, #0xDF        @ System mode
+	msr cpsr, #0xDF             @ System mode
 	ldr sp, =A9_STACK_END
 
 	bl setupTcms                @ Setup and enable DTCM and ITCM