wip

pyemu/Z80/dasm.py

@@ -0,0 +1,96 @@
+# Copyright 2008 Djordjevic Nebojsa <djnesh@gmail.com>
+# 
+# This file is part of py-emu.
+# 
+# py-emu is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# py-emu is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with py-emu.  If not, see <http://www.gnu.org/licenses/>.
+
+from dasmtab import *
+from pyemu.tools import as_signed8 as as_signed
+
+__all__ = ('dasm',)
+
+def dasm(adr, read):
+    """ This function will disassemble a single command and
+        return the number of bytes disassembled.
+    """
+
+    pos = adr
+    b = read(pos)
+    pos += 1
+    j = False
+
+    if b == 0xCB:
+        b = read(pos)
+        pos += 1
+        t = MNEMONICS_CB[b]
+    elif b == 0xED:
+        b = read(pos)
+        pos += 1
+        t = MNEMONICS_ED[b]
+    elif b == 0xDD:
+        c = 'X'
+        b = read(pos)
+        pos += 1
+        if b != 0xCB:
+            t = MNEMONICS_XX[b]
+        else:
+            offset = read(pos)
+            pos += 1
+            j = True
+            b = read(pos)
+            pos += 1
+            t = MNEMONICS_XCB[b]
+    elif b == 0xFD:
+        c = 'Y'
+        b = read(pos)
+        pos += 1
+        if b != 0xCB:
+            t = MNEMONICS_XX[b]
+        else:
+            offset = read(pos)
+            pos += 1
+            j = True
+            b = read(pos)
+            pos += 1
+            t = MNEMONICS_XCB[b]
+    else:
+        t = MNEMONICS[b]
+
+    if '^' in t:
+        op = as_signed(read(pos))
+        pos += 1
+        op = '%+d' % op
+        t = t.replace('^', op)
+    if '%' in t:
+        t = t.replace('%', c)
+    if '*' in t:
+        op = read(pos)
+        pos += 1
+        op = '%02Xh' % op
+        t = t.replace('*', op)
+    else:
+        if '@' in t:
+            if not j:
+                offset = read(pos)
+                pos += 1
+            j = '%+d' % as_signed(offset)
+            t = t.replace('@', j)
+        else:
+            if '#' in t:
+                lo = read(pos)
+                pos += 1
+                hi = read(pos)
+                pos += 1
+                t = t.replace('#', '%04Xh' % (lo + 256 * hi))
+    return t, pos - adr