Decomp OSAudioSystem

Former-commit-id: 470890cf81

e_files.mk

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+# Files with unscheduled epilogues.
+
+
+EPILOGUE_UNSCHEDULED:=\
+	$(EPILOGUE_DIR)/src/Dolphin/os/OSAudioSystem.o\

tools/frank.py

@@ -0,0 +1,95 @@
+#! /usr/bin/env python3
+
+# Written by Ethan Roseman (ethteck)
+# MIT License
+# Copyright 2021
+
+# Modified by EpochFlame
+
+import argparse
+
+# Byte sequence that marks code size
+CODESIZE_MAGIC = b"\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00\x00\x34"
+BLR_BYTE_SEQ = b"\x4E\x80\x00\x20"
+MTLR_BYTE_SEQ = b"\x7C\x08\x03\xA6"
+
+# Byte sequence array for branches to link register
+BLR_BYTE_SEQ_ARRAY = [BLR_BYTE_SEQ,
+b"\x4D\x80\x00\x20", b"\x4D\x80\x00\x21", b"\x4C\x81\x00\x20", b"\x4C\x81\x00\x21",
+b"\x4D\x82\x00\x20", b"\x4D\x82\x00\x21", b"\x4C\x80\x00\x20", b"\x4C\x80\x00\x21",
+b"\x4D\x81\x00\x20", b"\x4D\x81\x00\x21", b"\x4C\x80\x00\x20", b"\x4C\x80\x00\x21",
+b"\x4C\x82\x00\x20", b"\x4C\x82\x00\x21", b"\x4C\x81\x00\x20", b"\x4C\x81\x00\x21",
+b"\x4D\x83\x00\x20", b"\x4D\x83\x00\x21", b"\x4C\x83\x00\x20", b"\x4C\x83\x00\x21",
+b"\x4D\x83\x00\x20", b"\x4D\x83\x00\x21", b"\x4C\x83\x00\x20", b"\x4C\x83\x00\x21"]
+
+# Example invocation: ./frank.py vanilla.o profile.o output.o
+parser = argparse.ArgumentParser()
+parser.add_argument("vanilla", help="Path to the vanilla object", type=argparse.FileType('rb'))
+parser.add_argument("profile", help="Path to the profile object", type=argparse.FileType('rb'))
+parser.add_argument("target", help="Path to the target object (to write)")
+
+args = parser.parse_args()
+
+# Read contents into bytearrays and close files
+vanilla_bytes = args.vanilla.read()
+args.vanilla.close()
+profile_bytes = args.profile.read()
+args.profile.close()
+
+# Remove byte sequence
+stripped_bytes = profile_bytes.replace(b"\x48\x00\x00\x01\x60\x00\x00\x00", b"")
+
+# Find end of code sections in vanilla and stripped bytes
+code_size_offset = (vanilla_bytes.find(CODESIZE_MAGIC) + 12)
+code_size_bytes = vanilla_bytes[code_size_offset:code_size_offset+4]
+code_size = int.from_bytes(code_size_bytes, byteorder='big')
+
+eoc_offset = 0x34 + code_size
+
+# Break if the eoc is not found
+assert(eoc_offset != len(vanilla_bytes))
+
+# Replace 0x34 - eoc in vanilla with bytes from stripped
+final_bytes = vanilla_bytes[:0x34] + stripped_bytes[0x34:eoc_offset] + vanilla_bytes[eoc_offset:]
+
+# Fix branches to link register
+for seq in BLR_BYTE_SEQ_ARRAY:
+    idx = 0
+
+    while idx < len(vanilla_bytes):
+        found_pos = vanilla_bytes.find(seq, idx)
+        if found_pos == -1:
+            break # break while loop when no targets remain
+        if found_pos % 4 != 0: # check 4-byte alignment
+            idx += 4
+            continue
+        final_bytes = final_bytes[:found_pos] + vanilla_bytes[found_pos:found_pos+4] + final_bytes[found_pos+4:]
+        idx = found_pos + len(seq)
+
+# Reunify mtlr/blr instructions, shifting intermediary instructions up
+idx = 0
+
+while idx < len(final_bytes):
+    # Find mtlr position
+    mtlr_found_pos = final_bytes.find(MTLR_BYTE_SEQ, idx)
+    if mtlr_found_pos == -1:
+        break # break while loop when no targets remain
+    if mtlr_found_pos % 4 != 0: # check 4-byte alignment
+        idx += 4
+        continue
+    # Find paired blr position
+    blr_found_pos = final_bytes.find(BLR_BYTE_SEQ, mtlr_found_pos)
+    if blr_found_pos == -1:
+        break # break while loop when no targets remain
+    if blr_found_pos % 4 != 0: # check 4-byte alignment
+        idx += 4
+        continue
+    if mtlr_found_pos + 4 == blr_found_pos:
+        idx += 4
+        continue # continue if mtlr is followed directly by blr
+    
+    final_bytes = final_bytes[:mtlr_found_pos] + final_bytes[mtlr_found_pos+4:blr_found_pos] + final_bytes[mtlr_found_pos:mtlr_found_pos+4] + final_bytes[blr_found_pos:]
+    idx = mtlr_found_pos + len(MTLR_BYTE_SEQ)
+
+with open(args.target, "wb") as f:
+    f.write(final_bytes)

tools/franklite.py

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+#! /usr/bin/env python3
+
+# Written by Ethan Roseman (ethteck)
+# MIT License
+# Copyright 2021
+
+# Modified by EpochFlame
+
+import argparse
+
+# Byte sequences
+BLR_BYTE_SEQ = b"\x4E\x80\x00\x20"
+MTLR_BYTE_SEQ = b"\x7C\x08\x03\xA6"
+
+# Example invocation: ./frank.py vanilla.o profile.o output.o
+parser = argparse.ArgumentParser()
+parser.add_argument("vanilla", help="Path to the vanilla object", type=argparse.FileType('rb'))
+parser.add_argument("target", help="Path to the target object (to write)")
+
+args = parser.parse_args()
+
+# Read contents into bytearrays and close files
+vanilla_bytes = args.vanilla.read()
+args.vanilla.close()
+
+# Reunify mtlr/blr instructions, shifting intermediary instructions up
+idx = 0
+
+while idx < len(vanilla_bytes):
+    # Find mtlr position
+    mtlr_found_pos = vanilla_bytes.find(MTLR_BYTE_SEQ, idx)
+    if mtlr_found_pos == -1:
+        break # break while loop when no targets remain
+    if mtlr_found_pos % 4 != 0: # check 4-byte alignment
+        idx += 4
+        continue
+    # Find paired blr position
+    blr_found_pos = vanilla_bytes.find(BLR_BYTE_SEQ, mtlr_found_pos)
+    if blr_found_pos == -1:
+        break # break while loop when no targets remain
+    if blr_found_pos % 4 != 0: # check 4-byte alignment
+        idx += 4
+        continue
+    if mtlr_found_pos + 4 == blr_found_pos:
+        idx += 4
+        continue # continue if mtlr is followed directly by blr
+    
+    vanilla_bytes = vanilla_bytes[:mtlr_found_pos] + vanilla_bytes[mtlr_found_pos+4:blr_found_pos] + vanilla_bytes[mtlr_found_pos:mtlr_found_pos+4] + vanilla_bytes[blr_found_pos:]
+    idx = mtlr_found_pos + len(MTLR_BYTE_SEQ)
+
+with open(args.target, "wb") as f:
+    f.write(vanilla_bytes)