BITS 64

main: ; Replacement entry point
    push rbp
    mov rbp, rsp
    sub rsp, 30h + 90h


    call GetKernel32ModuleHandle
    mov [rbp - 8h], rax   ; kernel32.dll

    mov rcx, rax
    call GetAddressOf_GetProcAddress
    mov [rbp - 10h], rax  ; *GetProcAddress


    mov rcx, [rbp - 8h]   ; kernel32.dll
    lea rdx, [rel s_LoadLibraryA]
    mov rax, [rbp - 10h]  ; *GetProcAddress
    call rax              ; rax = *LoadLibraryA

    lea rcx, [rel dllPath]
    call rax              ; LoadLibraryA(dllPath)    


    mov rcx, [rbp - 8h]   ; kernel32.dll
    lea rdx, [rel s_GetModuleHandleA]
    mov rax, [rbp - 10h]  ; *GetProcAddress
    call rax              ; rax = *GetModuleHandle
    mov [rbp - 18h], rax

    mov rcx, 0
    call rax              ; rax = .exe base address
    mov [rbp - 20h], rax

    mov rcx, [rbp - 8h]   ; kernel32.dll
    lea rdx, [rel s_GetCommandLineW]
    mov rax, [rbp - 10h]  ; *GetProcAddress
    call rax              ; rax = *GetCommandLineW
    
    call rax              ; rax = command line
    mov [rbp - 28h], rax


    lea rcx, [rel s_UnityPlayer.dll]
    mov rax, [rbp - 18h]  ; *GetModuleHandleA
    call rax              ; rax = UnityPlayer.dll

    mov rcx, rax
    lea rdx, [rel s_UnityMain]
    mov rax, [rbp - 10h]  ; *GetProcAddress
    call rax              ; rax = *UnityMain

    mov rcx, [rbp - 20h]  ; .exe base address
    mov rdx, 0            ; hPrevInstance - 0
    mov r8, [rbp - 28h]   ; command line
    mov r9, 1             ; SW_NORMAL
    call rax              ; UnityMain(...)


    add rsp, 30h + 90h
    pop rbp
    ret


%include "gpa.asm"


; Strings
s_LoadLibraryA:      db "LoadLibraryA", 0
s_GetModuleHandleA:  db "GetModuleHandleA", 0
s_GetCommandLineW:   db "GetCommandLineW", 0
s_UnityPlayer.dll:   db "UnityPlayer.dll", 0
s_UnityMain:         db "UnityMain", 0

dllPath:
    ; This will be filled out by the launcher payload dll
    ; Path to the dll to inject into the game