Split code into multiple files

src/data/syscalls.asm

@@ -0,0 +1,9 @@
+SYS_READ     equ         0
+SYS_WRITE    equ         1
+SYS_OPEN     equ         2
+SYS_CLOSE    equ         3
+SYS_SOCKET   equ         41
+SYS_SENDTO   equ         44
+SYS_RECVFROM equ         45
+SYS_EXIT     equ         60
+

src/data/teeworlds.asm

@@ -0,0 +1,5 @@
+; tw protocol
+MSG_CTRL_TOKEN db 0x04, 0x00, 0x00, 0x0FF, 0xFF, 0xFF, 0xFF, 0x05, 0x51, 0x3B, 0x59, 0x46, 512 dup (0x00)
+MSG_CTRL_TOKEN_LEN equ $ - MSG_CTRL_TOKEN
+NET_MAX_PACKETSIZE equ 1400
+

src/hex.asm

@@ -0,0 +1,50 @@
+hex_to_char:
+    ; hex_to_char [rax]
+    ;
+    ; moves byte in `rax` as hex string into
+    ; the `hex_str` variable
+    ; https://stackoverflow.com/a/18879886/6287070
+    push rbx
+    push rax
+    mov rbx, HEX_TABLE
+
+    mov ah, al
+    shr al, 4
+    and ah, 0x0f
+    xlat
+    xchg ah, al
+    xlat
+
+    mov rbx, hex_str
+    xchg ah, al
+    mov [rbx], rax
+
+    pop rax
+    pop rbx
+    ret
+
+print_hex_byte:
+    ; print_hex [rax]
+    ;
+    ; prints given arg as hex string
+    ; to stdout
+    push rax
+    push rdi
+    push rsi
+    push rdx
+    push rcx
+
+    call hex_to_char
+
+    mov eax, SYS_WRITE
+    mov edi, STDOUT
+    mov rsi, hex_str ; movabs
+    mov edx, 0x2
+    syscall
+
+    pop rcx
+    pop rdx
+    pop rsi
+    pop rdi
+    pop rax
+    ret

src/logger.asm

@@ -19,3 +19,77 @@ print_newline:
     pop rax
     ret
 
+dbg_print_uint32:
+    ; dbg_print_num [rax]
+    ;
+    ; prints given arg as uint32 turned into a string
+    ; to stdout
+    ; prefixed with a debug string message
+
+    push rax
+    push rdi
+    push rsi
+    push rdx
+
+    mov rsi, s_dbg_digit
+    mov eax, SYS_WRITE
+    mov edi, STDOUT
+    mov edx, l_dbg_digit
+    syscall
+
+    pop rdx
+    pop rsi
+    pop rdi
+    pop rax
+
+    call print_uint32
+    call print_newline
+
+    ret
+
+print_uint32:
+    ; print_uint32 [rax]
+    ;
+    ; has a sub label toascii_digit
+    ; and prints the given value in rax
+    ; as a digit to stdout
+    ; https://stackoverflow.com/a/46301894/6287070
+    push rax
+    push rsi
+    push rcx
+    push rdx
+
+    mov ecx, 0xa ; base 10
+    push rcx ; ASCII newline '\n' = 0xa = base
+    mov rsi, rsp
+    sub rsp, 16 ; not needed on 64-bit Linux, the red-zone is big enough.  Change the LEA below if you remove this.
+
+;;; rsi is pointing at '\n' on the stack, with 16B of "allocated" space below that.
+.print_uint32_toascii_digit:                ; do {
+    xor edx, edx
+    div ecx ; edx=remainder = low digit = 0..9.  eax/=10
+                                 ;; DIV IS SLOW.  use a multiplicative inverse if performance is relevant.
+    add edx, '0'
+    dec rsi ; store digits in MSD-first printing order, working backwards from the end of the string
+    mov [rsi], dl
+
+    test eax,eax ; } while(x);
+    jnz  .print_uint32_toascii_digit
+;;; rsi points to the first digit
+
+
+    mov eax, SYS_WRITE
+    mov edi, STDOUT
+    ; pointer already in RSI    ; buf = last digit stored = most significant
+    lea edx, [rsp+16 + 1]    ; yes, it's safe to truncate pointers before subtracting to find length.
+    sub edx, esi             ; RDX = length = end-start, including the \n
+    syscall                     ; write(1, string /*RSI*/,  digits + 1)
+
+    add rsp, 24                ; (in 32-bit: add esp,20) undo the push and the buffer reservation
+
+    pop rdx
+    pop rcx
+    pop rsi
+    pop rax
+    ret
+