From 7dec8b6c81be45800d6d54cbdef19c6aa62e5750 Mon Sep 17 00:00:00 2001
From: Ain <41307858+nero@users.noreply.github.com>
Date: Mon, 14 Oct 2019 21:04:40 +0000
Subject: [PATCH] Use nasm compat file to allow custom asm variant

(I dont want to re-implement all those nasm features later)
---
 Makefile         |   2 +-
 lib/nasmcomp.asm | 124 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 lib/nasmcomp.asm

diff --git a/Makefile b/Makefile
index 79aac34..5229dd6 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ QEMU = qemu-system-$(QEMU_ARCH)
 QEMU_ARGS = $(addprefix --option-rom ,$(ROMS))
 
 NASM = nasm
-NASM_ARGS = -s -I lib
+NASM_ARGS = -s -Ilib -Plib/nasmcomp.asm -w-macro-params
 
 EMUL = utils/emul
 
diff --git a/lib/nasmcomp.asm b/lib/nasmcomp.asm
new file mode 100644
index 0000000..4fbebf8
--- /dev/null
+++ b/lib/nasmcomp.asm
@@ -0,0 +1,124 @@
+; Pseudo-Instruction: fill bytes until offset
+%macro pad 1.nolist
+times (%1 - ($-$$)) nop
+%endmacro
+
+; REGISTERS
+%define a al
+%define b ch
+%define c cl
+%define d dh
+%define e dl
+%define h bh
+%define l bl
+%define m byte [bx]
+
+; REGISTER PAIRS
+%define bc cx
+%define de dx
+%define hl bx
+
+; INSTRUCTIONS
+; data movement
+; 'mov' can stay literal
+%define mvi mov
+%define lxi mov
+%macro lda 1
+  mov al, byte [%1]
+%endmacro
+%macro sta 1
+  mov byte [%1], al
+%endmacro
+%macro lhld 1
+  mov bx, word [%1]
+%endmacro
+%macro shld 1
+  mov word [%1], bx
+%endmacro
+%macro ldax 1
+  mov al, byte [%1]
+%endmacro
+%macro stax 1
+  mov byte [%1], al
+%endmacro
+%macro xchg 1
+  xchg dx, bx
+%endmacro
+; addition
+%macro add 1
+  add al, %1
+%endmacro
+%macro adi 1
+  add al, %1
+%endmacro
+%macro adc 1
+  adc al, %1
+%endmacro
+%macro aci 1
+  adc al, %1
+%endmacro
+; subtraction
+%macro sub 1
+  sub al, %1
+%endmacro
+%macro sui 1
+  sub al, %1
+%endmacro
+%macro sbb 1
+  sub al, %1
+%endmacro
+%macro sbi 1
+  sub al, %1
+%endmacro
+; increment / decrement
+%define inr inc
+%define dcr dec
+%define inx inc
+%define dcx dec
+; pointer arithmetic
+%macro dad 1
+  add bx, %1
+%endmacro
+; 'daa' stays literal
+
+;ANA S     10100SSS          ZSCPA   AND register with A
+;ANI #     11100110 db       ZSPCA   AND immediate with A
+;ORA S     10110SSS          ZSPCA   OR  register with A
+;ORI #     11110110          ZSPCA   OR  immediate with A
+;XRA S     10101SSS          ZSPCA   ExclusiveOR register with A
+;XRI #     11101110 db       ZSPCA   ExclusiveOR immediate with A
+
+;CMP S     10111SSS          ZSPCA   Compare register with A
+;CPI #     11111110          ZSPCA   Compare immediate with A
+
+;RLC       00000111          C       Rotate A left
+;RRC       00001111          C       Rotate A right
+;RAL       00010111          C       Rotate A left through carry
+;RAR       00011111          C       Rotate A right through carry
+;CMA       00101111          -       Compliment A
+;CMC       00111111          C       Compliment Carry flag
+;STC       00110111          C       Set Carry flag
+;JMP a     11000011 lb hb    -       Unconditional jump
+;Jccc a    11CCC010 lb hb    -       Conditional jump
+;CALL a    11001101 lb hb    -       Unconditional subroutine call
+;Cccc a    11CCC100 lb hb    -       Conditional subroutine call
+;RET       11001001          -       Unconditional return from subroutine
+;Rccc      11CCC000          -       Conditional return from subroutine
+;RST n     11NNN111          -       Restart (Call n*8)
+;PCHL      11101001          -       Jump to address in H:L
+;PUSH RP   11RP0101 *2       -       Push register pair on the stack
+;POP RP    11RP0001 *2       *2      Pop  register pair from the stack
+;XTHL      11100011          -       Swap H:L with top word on stack
+;SPHL      11111001          -       Set SP to content of H:L
+;IN p      11011011 pa       -       Read input port into A
+;OUT p     11010011 pa       -       Write A to output port
+;EI        11111011          -       Enable interrupts
+;DI        11110011          -       Disable interrupts
+;HLT       01110110          -       Halt processor
+;NOP       00000000          -       No operation
+
+%macro cnz 1
+  jz %%skip
+  call near %1
+%%skip:
+%endmacro