grml...

[seabios.git] / tools / buildrom.py

diff --git a/tools/buildrom.py b/tools/buildrom.py
index fd490761e2bcae1f3ccf87c1bbaec8f67ce6023e..7ed8107b2dc0838240ae52ab6d241d8449468bfa 100755 (executable)
--- a/tools/buildrom.py
+++ b/tools/buildrom.py
@@ -1,82 +1,48 @@
 #!/usr/bin/env python
-# Script to merge a rom32.bin file into a rom16.bin file.
+# Fill in checksum/size of an option rom, and pad it to proper length.
 #
-# Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2009  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 
 import sys
-import struct
 
-ROM16='out/rom16.bin'
-ROM32='out/rom32.bin'
-OFFSETS16='out/rom16.offset.auto.h'
-OFFSETS32='out/rom32.offset.auto.h'
-OUT='out/rom.bin'
-
-def align(v, a):
-    return (v + a - 1) // a * a
-
-def scanconfig(file):
-    f = open(file, 'rb')
-    opts = {}
-    for l in f.readlines():
-        parts = l.split()
-        if len(parts) != 3:
-            continue
-        if parts[0] != '#define':
-            continue
-        opts[parts[1]] = parts[2]
-    return opts
-
-def alteraddr(data, offset, ptr):
-    rel = struct.pack("<i", ptr)
-    return data[:offset] + rel + data[offset+4:]
+def alignpos(pos, alignbytes):
+    mask = alignbytes - 1
+    return (pos + mask) & ~mask
 
+def checksum(data):
+    ords = map(ord, data)
+    return sum(ords)
 
 def main():
-    # Read in files
-    f = open(ROM16, 'rb')
-    data16 = f.read()
-    f = open(ROM32, 'rb')
-    data32 = f.read()
+    inname = sys.argv[1]
+    outname = sys.argv[2]
 
-    if len(data16) != 65536:
-        print "16bit code is not 65536 bytes long"
-        sys.exit(1)
+    # Read data in
+    f = open(inname, 'rb')
+    data = f.read()
+    count = len(data)
 
-    # Get config options
-    o16 = scanconfig(OFFSETS16)
-    o32 = scanconfig(OFFSETS32)
+    # Pad to a 512 byte boundary
+    data += "\0" * (alignpos(count, 512) - count)
+    count = len(data)
 
-    # Inject 32bit code
-    spos = align(int(o16['OFFSET_bios16c_end'], 16), 16)
-    epos = int(o16['OFFSET_post16'], 16)
-    size32 = len(data32)
-    freespace = epos - spos
-    if size32 > freespace:
-        print "32bit code too large (%d vs %d)" % (size32, freespace)
-        sys.exit(1)
-    if data16[spos:spos+size32] != '\0'*size32:
-        print "Non zero data in 16bit freespace (%d to %d)" % (
-            spos, spos+size32)
-        sys.exit(1)
-    outrom = data16[:spos] + data32 + data16[spos+size32:]
+    # Check if a pci header is present
+    pcidata = ord(data[24:25]) + (ord(data[25:26]) << 8)
+    if pcidata != 0:
+        data = data[:pcidata + 16] + chr(count/512) + chr(0) + data[pcidata + 18:]
 
-    # Fixup initial jump to 32 bit code
-    jmppos = int(o16['OFFSET_set_entry32'], 16)
-    start32 = int(o32['OFFSET__start'], 16)
-    outrom = alteraddr(outrom, jmppos+2, start32)
+    # Fill in size field; clear checksum field
+    data = data[:2] + chr(count/512) + data[3:6] + "\0" + data[7:]
 
-    print "Writing output rom %s" % OUT
-    print " 16bit C-code size: %d" % spos
-    print " 32bit C-code size: %d" % size32
-    print " Total C-code size: %d" % (spos+size32)
+    # Checksum rom
+    newsum = (256 - checksum(data)) & 0xff
+    data = data[:6] + chr(newsum) + data[7:]
 
-    # Write output rom
-    f = open(OUT, 'wb')
-    f.write(outrom)
-    f.close()
+    # Write new rom
+    f = open(outname, 'wb')
+    f.write(data)
 
 if __name__ == '__main__':
     main()