Function at 0x420870
Capabilities:
Check for time delay via queryperformancecounter
Read file on windows

Disassembly:
push ebx
push esi
push edi
push ebp
add esp, 0xfffff014
mov byte [esp], dl
mov edi, eax
lea ebx, [esp + 0x20]
push 4
push 0x1000
push 0x20000
push 0
call sub.kernel32.dll_VirtualAlloc_1
mov dword [esp + 4], eax
push 0
push 3
mov eax, dword [edi + 0x58]
mov edx, dword [edi + 0x5c]
call fcn.00404654
push edx
push eax
mov eax, dword [edi + 0x50]
dec eax
xor edx, edx
not eax
not edx
and eax, dword [esp]
and edx, dword [esp + 4]
add esp, 8
mov dword [esp + 0x10], eax
mov dword [esp + 0x14], edx
lea eax, [esp + 0x18]
push eax
call sub.kernel32.dll_QueryPerformanceFrequency
push 0
push 0
push dword [esp + 0x1c]
push dword [esp + 0x1c]
mov eax, dword [edi + 0x28]
push eax
call sub.kernel32.dll_SetFilePointerEx
push 0
lea eax, [esp + 0xc]
push eax
mov eax, dword [edi + 0x50]
push eax
mov eax, dword [esp + 0x10]
push eax
mov eax, dword [edi + 0x28]
push eax
call sub.kernel32.dll_ReadFile
mov ebp, 0x1f5
lea esi, [esp + 0x34]
push ebx
call sub.kernel32.dll_QueryPerformanceCounter
push 0
lea eax, [esp + 0xc]
push eax
push 0x20000
mov eax, dword [esp + 0x10]
push eax
mov eax, dword [edi + 0x28]
push eax
call sub.kernel32.dll_ReadFile
lea eax, [esp + 0x28]
push eax
call sub.kernel32.dll_QueryPerformanceCounter
cmp byte [esp], 0
je 0x42094f
push 0
push 0
push dword [esp + 0x1c]
push dword [esp + 0x1c]
mov eax, dword [edi + 0x28]
push eax
call sub.kernel32.dll_SetFilePointerEx
jmp 0x42097c
mov eax, dword [esp + 0x10]
mov edx, dword [esp + 0x14]
add eax, 0x20000
adc edx, 0
mov dword [esp + 0x10], eax
mov dword [esp + 0x14], edx
push 0
push 0
push dword [esp + 0x1c]
push dword [esp + 0x1c]
mov eax, dword [edi + 0x28]
push eax
call sub.kernel32.dll_SetFilePointerEx
mov eax, dword [esp + 0x28]
mov edx, dword [esp + 0x2c]
cmp edx, dword [ebx + 4]
jne 0x42098f
cmp eax, dword [ebx]
jbe 0x42099b
jmp 0x420991
jle 0x42099b
mov eax, dword [esp + 0x28]
sub eax, dword [ebx]
mov dword [esi], eax
jmp 0x4209a9
mov eax, dword [ebx]
sub eax, dword [esp + 0x28]
mov edx, dword [esp + 0x18]
sub edx, eax
mov dword [esi], edx
mov eax, dword [0x4438a8]
call fcn.0040bbc0
add esi, 4
dec ebp
jne 0x420908
push 0x8000
push 0
mov eax, dword [esp + 0xc]
push eax
call sub.kernel32.dll_VirtualFree_1
mov ebp, 0x1f5
lea esi, [esp + 0x34]
mov eax, dword [esi]
mov dword [esp + 0xfe4], eax
xor eax, eax
mov dword [esp + 0xfe8], eax
fild qword [esp + 0xfe4]
fild qword [esp + 0x18]
fdivp st(1)
fdivr dword [0x420b60]
add esp, 0xfffffff8
fstp qword [esp]
wait
lea eax, [esp + 0xfe4]
call fcn.00406208
mov eax, dword [esp + 0xfdc]
mov dword [esi], eax
add esi, 4
dec ebp
jne 0x4209d7
cmp byte [esp], 0
je 0x420a58
mov word [edi + 0x6b6], 0
mov ebp, 0x1f5
lea eax, [esp + 0x34]
mov edx, dword [eax]
movzx ecx, word [edi + 0x6b6]
cmp edx, ecx
jbe 0x420a4d
mov dx, word [eax]
mov word [edi + 0x6b6], dx
add eax, 4
dec ebp
jne 0x420a36
jmp 0x420b53
xor ecx, ecx
mov ebp, 0x1f5
lea eax, [esp + 0x34]
add ecx, dword [eax]
add eax, 4
dec ebp
jne 0x420a63
mov eax, ecx
mov ecx, 0x1f5
xor edx, edx
div ecx
mov word [edi + 0x6b4], ax
xor ebp, ebp
lea edx, [esp + 0x34]
lea esi, [esp + 0x808]
mov dword [esp + 0x30], 1
lea ecx, [ebp + 1]
cmp ecx, 0x1f3
ja 0x420ab7
lea eax, [esp + ecx*4 + 0x34]
mov ebx, dword [edx]
cmp ebx, dword [eax]
jne 0x420aab
inc dword [esp + 0x30]
inc ecx
add eax, 4
cmp ecx, 0x1f4
jne 0x420aa1
mov eax, dword [esp + 0x30]
mov dword [esi], eax
inc ebp
add esi, 4
add edx, 4
cmp ebp, 0x1f5
jne 0x420a8a
xor eax, eax
xor ebp, ebp
lea edx, [esp + 0x808]
cmp eax, dword [edx]
jae 0x420add
mov eax, ebp
inc ebp
add edx, 4
cmp ebp, 0x1f5
jne 0x420ad7
mov ax, word [esp + eax*4 + 0x34]
mov word [edi + 0x6ba], ax
mov word [edi + 0x6b8], 0
mov ebp, 0x1f5
lea eax, [esp + 0x34]
mov edx, dword [eax]
movzx ecx, word [edi + 0x6b8]
cmp edx, ecx
jbe 0x420b1e
mov dx, word [eax]
mov word [edi + 0x6b8], dx
add eax, 4
dec ebp
jne 0x420b07
mov word [edi + 0x6be], 0xffff
mov ebp, 0x1f5
lea eax, [esp + 0x34]
mov edx, dword [eax]
movzx ecx, word [edi + 0x6be]
cmp edx, ecx
jae 0x420b4d
mov dx, word [eax]
mov word [edi + 0x6be], dx
add eax, 4
dec ebp
jne 0x420b36
add esp, 0xfec
pop ebp
pop edi
pop esi
pop ebx
ret