update to ida 7.6, add builds

idasdk76/ldr/script_ldrs/bios_image.py

@@ -0,0 +1,114 @@
+
+import sys
+
+import idaapi
+import idc
+
+# -----------------------------------------------------------------------
+def accept_file(li, filename):
+    # ignore any trailer; align on 64KB boundary
+
+    size = li.size()
+    if (size & 0xFFF) != 0:
+        size &= ~0xFFFF
+
+    if size < 16:
+        return 0
+
+    # check the code at F000:FFF0
+    li.seek(size-16);
+    jump = li.read(16)
+    # skip any nops
+    while jump[:1] == b'\x90':
+        jump = jump[1:]
+    # skip wbinvd
+    if jump.startswith(b'\x0F\x09'):
+        jump = jump[2:]
+
+    _byte = ord if sys.version_info.major < 3 else lambda t: t
+
+    # is it a jump?
+    if (
+        jump.startswith(b'\xEA')       # jmp ptr16:16  EA oo oo ss ss
+        and len(jump) >= 5
+        and 0xF0 <= _byte(jump[4]) <= 0xFE # segment should be above F000
+       ) or (
+        jump.startswith(b'\xE9')       # jmp rel16    E9 ll hh
+        and len(jump) >= 3
+        # and (_byte(jump[2]) & 0x80) != 0 # jump backwards
+       ) or (
+        jump.startswith(b'\xEB')       # jmp rel8     EB dd
+        and len(jump) >= 2
+        and (_byte(jump[1]) & 0x80) != 0 # jump backwards
+       ):
+        return {'format': "BIOS Image", 'processor':'metapc'} # accept the file
+
+    return 0
+
+
+def myAddSeg(startea, endea, base, use32, name, clas):
+    s = idaapi.segment_t()
+    s.start_ea = startea
+    s.end_ea   = endea
+    s.sel      = idaapi.setup_selector(base)
+    s.bitness  = use32
+    s.align    = idaapi.saRelPara
+    s.comb     = idaapi.scPub
+    idaapi.add_segm_ex(s, name, clas, idaapi.ADDSEG_NOSREG|idaapi.ADDSEG_OR_DIE)
+
+# -----------------------------------------------------------------------
+def load_file(li, neflags, format):
+    chunksize = 0x10000
+    base  = 0xF000
+    start = base << 4;
+    size = li.size()
+    if (size & 0xFFF) != 0:
+      size &= ~0xFFFF
+    offs = size - chunksize
+
+    idaapi.set_processor_type("metapc", idaapi.SETPROC_LOADER)
+
+    if size < chunksize:
+      offs = 0
+      start += (chunksize - size)
+      chunksize = size
+
+    # make E and F segments for real-mode part
+    myAddSeg(start, start+chunksize, base, 0, "BIOS_F", "CODE")
+    li.file2base(offs, start, start+chunksize, 1)
+    if offs > 0 and base > 0xE000:
+      base  -= 0x1000
+      start -= chunksize
+      offs  -= chunksize
+      myAddSeg(start, start+chunksize, base, 0, "BIOS_%X" % (base>>12), "CODE")
+      li.file2base(offs, start, start+chunksize, 1)
+      # set default ds to point to the current segment
+      idc.set_default_sreg_value(start, "ds", base)
+
+    if offs > 0:
+      # file is bigger than 128KB
+      # make a flat 32-bit segment for the flash alias area
+      start = (-size) & 0xFFFFFFFF # place it so that it ends at 4GB
+      chunksize = size
+      if not idc.__EA64__:
+        chunksize -= 2 # truncate last two bytes to avoid address space overlap
+      # map the whole file
+      offs = 0
+      base = 0
+      myAddSeg(start, start+chunksize, base, 1, "BIOS_FLASH", "CODE")
+      li.file2base(offs, start, start+chunksize, 1)
+
+    # set the entry registers to F000:FFF0
+    idc.set_inf_attr(idc.INF_START_IP, 0xFFF0)
+    idc.set_inf_attr(idc.INF_START_CS, 0xF000)
+    # turn off "Convert 32bit instruction operand to offset", too many false positives in high areas
+    idc.set_inf_attr(idc.INF_AF, idc.get_inf_attr(idc.INF_AF) & ~idc.AF_IMMOFF)
+    # turn off "Create function tails"
+    idc.set_inf_attr(idc.INF_AF, idc.get_inf_attr(idc.INF_AF) & ~idc.AF_FTAIL)
+
+    return 1
+
+# -----------------------------------------------------------------------
+def move_segm(frm, to, sz, fileformatname):
+    idc.warning("move_segm(from=%s, to=%s, sz=%d, formatname=%s" % (hex(frm), hex(to), sz, fileformatname))
+    return 0