;)

twasm/asm/main.asm

@@ -184,9 +184,9 @@ assemble:
   .operator_1_memory_access:
     push rsi
     mov rsi, .msg_operator_1_memory_access
-    call print.error
+    call print.debug
     pop rsi
-    jmp halt
+    jmp .unsupported_memory_access
 
   .operator_1_register:
     push rsi
@@ -254,9 +254,9 @@ assemble:
   .operator_2_memory_access:
     push rsi
     mov rsi, .msg_operator_2_memory_access
-    call print.error
+    call print.debug
     pop rsi
-    jmp halt
+    jmp .unsupported_memory_access
 
   .operator_2_register:
     push rsi
@@ -299,9 +299,38 @@ assemble:
   .operator_2_register_memory_access:
     push rsi
     mov rsi, .msg_operator_2_register_memory_access
-    call print.error
+    call print.debug
     pop rsi
-    jmp halt
+
+    cmp di, 0x1000                 ; check if token is addressing to a register
+    jne .unsupported_memory_access ; if not, unsupported :/
+
+    pop rax
+    pop rdi
+    inc rax
+    cmp rax, rdi
+    jge .break
+    push rdi
+    push rax
+    xor edi, edi
+    mov di, [rax * TOKEN_TABLE_ENTRY_SIZE + TOKEN_TABLE_ADDR] ; di = next tte
+
+    ; si = `R/M` tte
+    ; di = `reg` tte
+    push rsi
+    mov si, di
+    pop rdi
+    mov dl, 00b ; dl = mod bits
+    call get_ModRM
+    ; al = Mod R/M byte
+    call .output_byte
+
+    pop rax ; rax = number of tokens processed
+    pop rdi ; rdi = total number of tokens
+    inc rax
+    cmp rax, rdi
+    jge .break
+    jmp .loop
 
   .operator_2_register_register:
     push rsi
@@ -311,6 +340,9 @@ assemble:
 
     ; si = `R/M` tte
     ; di = `reg` tte
+    push rsi
+    mov si, di
+    pop rdi
     mov dl, 11b ; dl = mod bits
     call get_ModRM
     ; al = Mod R/M byte
@@ -331,6 +363,11 @@ assemble:
     call print.error
     jmp halt
 
+  .unsupported_memory_access:
+    mov rsi, .msg_unsupported_memory_access
+    call print.error
+    jmp halt
+
   ; procedures
 
   ; al = byte to write
@@ -343,7 +380,8 @@ assemble:
   .next_output_byte dd OUTPUT_ADDR ; next empty byte in output
                                    ; TODO get rid of this sketchy bit of state
 
-  .msg_unexpected_token db "unexpected token while assembling, aborting", 0x0A, 0x00
+  .msg_unexpected_token db "unexpected token, aborting", 0x0A, 0x00
+  .msg_unsupported_memory_access db "unsupported memory access, aborting", 0x0A, 0x00
   .msg_operator_0 db "operator_0", 0x0A, 0x00
   .msg_operator_1 db "operator_1", 0x0A, 0x00
   .msg_operator_1_memory_access db "operator_1_memory_access", 0x0A, 0x00
@@ -1677,7 +1715,7 @@ opcodes:
     db 0x00   ; reserved
 
     dw 0x0056 ; mov
-    db 0x89
+    db 0x8B
     db 0x00   ; reserved
 
     dw 0x004F ; hlt
@@ -1695,6 +1733,7 @@ program:
   db "xor eax, eax", 0x0A
   db "inc rax ; inline comment", 0x0A
   db "; one line comment", 0x0A
+  db "mov rdx, [rax]", 0x0A
   db "mov [rax], rdx", 0x0A
   db "hlt", 0x0A ; TODO make it so it doesn't need to end with a newline; this
                  ; would mean range checking members in operator/operand/com-