1 files changed, 68 insertions, 0 deletions
diff --git a/arm9/asm/OS_entropy.s b/arm9/asm/OS_entropy.s
new file mode 100644
index 00000000..839d54f9
--- /dev/null
+++ b/arm9/asm/OS_entropy.s
@@ -0,0 +1,68 @@
+    .include "asm/macros.inc"
+    .include "global.inc"
+
+    .text
+
+	arm_func_start OS_GetLowEntropyData
+OS_GetLowEntropyData: ; 0x020CD754
+	stmdb sp!, {r4-r7,lr}
+	sub sp, sp, #0x4
+	ldr r1, _020CD82C ; =0x04000006
+	ldr r2, _020CD830 ; =0x027FFC00
+	ldrh r7, [r1, #0x0]
+	add r4, r2, #0x80
+	mov r6, r0
+	add r5, r4, #0x74
+	bl OS_GetTickLo
+	orr r0, r0, r7, lsl #0x10
+	str r0, [r6, #0x0]
+	ldr r1, _020CD834 ; =OSi_TickCounter
+	ldr r0, _020CD830 ; =0x027FFC00
+	ldr r3, [r1, #0x0]
+	ldrh r5, [r5, #0x4]
+	ldr r2, [r1, #0x4]
+	ldr r2, _020CD838 ; =0x04000600
+	eor r3, r3, r5, lsl #0x10
+	str r3, [r6, #0x4]
+	ldr r3, [r1, #0x0]
+	ldr r3, [r1, #0x4]
+	ldr r1, [r4, #0x74]
+	ldr r4, [r0, #0x3c]
+	eor r1, r3, r1
+	eor r1, r4, r1
+	str r1, [r6, #0x8]
+	ldr r3, [r6, #0x8]
+	ldr r2, [r2, #0x0]
+	add r1, r0, #0x300
+	eor r2, r3, r2
+	str r2, [r6, #0x8]
+	ldr r2, [r0, #0x1e8]
+	ldr r3, _020CD83C ; =0x04000130
+	str r2, [r6, #0xc]
+	ldr r4, [r0, #0x1ec]
+	ldr r2, _020CD840 ; =0x027FFFA8
+	str r4, [r6, #0x10]
+	ldrh r4, [r1, #0x94]
+	ldr r0, [r0, #0x390]
+	eor r0, r0, r4, lsl #0x10
+	str r0, [r6, #0x14]
+	ldrh r4, [r1, #0xaa]
+	ldrh r0, [r1, #0xac]
+	orr r0, r0, r4, lsl #0x10
+	str r0, [r6, #0x18]
+	ldrh r3, [r3, #0x0]
+	ldrh r0, [r2, #0x0]
+	ldrh r1, [r1, #0x98]
+	orr r0, r3, r0
+	orr r0, r0, r1, lsl #0x10
+	str r0, [r6, #0x1c]
+	add sp, sp, #0x4
+	ldmia sp!, {r4-r7,lr}
+	bx lr
+	.balign 4
+_020CD82C: .word 0x04000006
+_020CD830: .word 0x027FFC00
+_020CD834: .word OSi_TickCounter
+_020CD838: .word 0x04000600
+_020CD83C: .word 0x04000130
+_020CD840: .word 0x027FFFA8