proper cartridge generation

- Pad to 128kb. snes9x header check reports corruption for less than 1 mbit (size < 7)
- setup.py - skip cc65 installation if done already
- quiet sneschk.bat

Author: mukunda-

.editorconfig

@@ -0,0 +1,13 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+root = true
+
+[*]
+indent_style = space
+indent_size = 3
+end_of_line = lf
+charset = utf-8
+
+[*.asm]
+indent_style = tab
+indent_size = 8

README.md

@@ -9,7 +9,7 @@
 
 After checking out the repo, run setup.py to install tools. 
 
-Recommended to add SNESKIT to your environment pointing to the SNESKIT folder.
+SNESKIT should be added to your environment pointing to the sneskit folder.
 
 ## Tool installations:
 
@@ -75,5 +75,8 @@ This is a graphics converter for SNES which is a modified version of the "GBA Ra
 Transmogrifier" by Cearn, which is distributed under the GPL. Please contact me
 ([email protected]) if you would like to obtain the [modified] source code.
 
+## Contributions welcome!
+Check the issues page for things to do.
+
 ## IRC
 Join #snesdev on EFNet!

setup.py

@@ -1,15 +1,21 @@
 #!/usr/bin/env python3
 #***********************************************************
 # Configure environment
-import venv, os, shutil
+import venv, os, shutil, glob
 
+print("Creating venv.")
 venv.create(".venv", with_pip=True)
+
+print("Activating venv.")
 if os.name == "nt":
    os.system(".venv\\Scripts\\activate")
 elif os.name == "posix":
    os.system("source .venv/bin/activate")
 
+print("Installing Python requirements.")
 os.system("pip install -r requirements.txt")
+
+print("Okay, ready for work.")
 #***********************************************************
 
 import os, requests, urllib.request, zipfile
@@ -23,6 +29,11 @@ def run(command):
 
 #-----------------------------------------------------------------------------------------
 def install_cc65():
+   print("Installing cc65.")
+   if glob.glob("cc65/*") != []:
+      print("*** cc65 has files in it. Skipping installation.")
+      return
+   
    if os.name == 'nt':
       # Windows
       # Download from sourceforge
@@ -41,13 +52,15 @@ def install_cc65():
 
 #-----------------------------------------------------------------------------------------
 def install_tools():
+   print("Installing tools.")
    if os.name == "posix":
+      # Linux calls the script directly.
       shutil.copy("tool-src/sneschk/sneschk.py", "tools/sneschk")
       os.chmod("tools/sneschk", 0o755)
    else:
-      shutil.copy("tool-src/sneschk/sneschk.py", "tools/sneschk.py")
       # Windows will use the corresponding .bat file to call the py file.
+      shutil.copy("tool-src/sneschk/sneschk.py", "tools/sneschk.py")
 
 #-----------------------------------------------------------------------------------------
 install_cc65()
-install_tools()
+install_tools()

templates/snes-project/.gitignore

@@ -0,0 +1 @@
+build

templates/snes-project/Makefile

@@ -10,8 +10,6 @@ ifeq ($(strip $(SNESKIT)),)
 $(error SNESKIT not found, please add SNESKIT=<path to sneskit> to your environment)
 endif
 
-# Might have to prefix .py tools with "py" on Windows Python3 installations.
-
 SNESTOOLS := $(SNESKIT)/tools
 SNESGRIT  := $(SNESTOOLS)/snesgrit
 SNESCHK   := $(SNESTOOLS)/sneschk
@@ -36,7 +34,7 @@ SOURCES  := source
 INCLUDES := include
 GRAPHICS := graphics
 AUDIO    := audio
-MAPMODE  := hirom
+MAPMODE  := lorom
 MAPFILE  := YES
 
 #-----------------------------------------------------------------------------------------
@@ -49,10 +47,14 @@ ASFLAGS     := --cpu 65816 -s
 # For snesmod (if used), we convert to a soundbank target.
 SOUNDBANK   := $(BUILD)/soundbank
 SMCONVFLAGS := --soundbank --output $(SOUNDBANK)
+SNESCHKFLAGS := --fix
 
 ifeq ($(MAPMODE),hirom)
 ASFLAGS     += -D HIROM
 SMCONVFLAGS += --hirom
+SNESCHKFLAGS += -m hirom
+else
+SNESCHKFLAGS += -m lorom
 endif
 
 # Include paths.
@@ -134,6 +136,6 @@ else
 endif
 
 	@echo "Running sneschk (checksums and padding)"
-	@$(SNESCHK) $@
+	$(SNESCHK) $(SNESCHKFLAGS) $@ 
 
 	@echo Okay! :: $(notdir $@)

templates/snes-project/config.ld

@@ -29,8 +29,11 @@ MEMORY {
 
 #-------------------------------------------------------------------------
 # Insert ROM sections for program data.
+# Note that some tools will say your cart is corrupt if it's smaller than
+# 1 mbit, hence 3 ROM sections here by default.
 	ROM1: start = $818000, size = $8000, fill = yes;
-#	ROM2: start = $828000, size = $8000, fill = yes;
+	ROM2: start = $820000, size = $8000, fill = yes;
+	ROM3: start = $828000, size = $8000, fill = yes;
 
 # For HiROM, use these instead of the above (size 64k, bank $C0+)
 #	ROM1: start = $C18000, size = $10000, fill = yes;

tool-src/sneschk/sneschk.py

@@ -26,21 +26,22 @@ def compute_romsize(filesize):
    return size_header, actualsize
 
 #-----------------------------------------------------------------------------------------
-def calc_checksum(file):
+def calc_checksum(file, header_start):
    file.seek(0, os.SEEK_SET)
+   checksum_addr = header_start + 0xDC
 
-   checksum = 0xFF * 2 # Default checksum bytes at FFDC and FFDD
+   checksum = 0xFF * 2 # Default checksum bytes at 7FDC and 7FDD
    address = 0
    while True:
       c = file.read(4096)
       if c == b'':
          break
 
       checksum += sum(c)
-      relative_ffdc = 0xFFDC - address
+      relative_ffdc = checksum_addr - address
       if relative_ffdc >= 0 and relative_ffdc < len(c):
          # This block contains the checksum bytes. Exclude them from the result.
-         checksum -= sum(c[0xFFDC - address:0xFFDC - address + 4])
+         checksum -= sum(c[checksum_addr - address:checksum_addr - address + 4])
 
       address += len(c)
 
@@ -67,9 +68,9 @@ def get_file_byte(file, address):
    return file.read(1)[0]
 
 #-----------------------------------------------------------------------------------------
-def validate_sfc(file):
+def validate_sfc(file, minsize):
    file.seek(0, os.SEEK_END)
-   if file.tell() < 0x10000:
+   if file.tell() < minsize: # Double on hirom.
       return "file is too small to contain a valid cartridge header."
 
    # Kind of hard to find any special signature to verify.
@@ -96,6 +97,7 @@ def main(args=None, output_file=None):
 """)
 
    parser.add_argument('path', help='Path to SFC or SMC file. Must be headerless.')
+   parser.add_argument("-m", "--mode", required=True, choices=['lorom', 'hirom'], help='Cartridge mode')
    parser.add_argument("--fix", action="store_true", help='Make changes to the given file. Otherwise, just print info about it.')
    parser.add_argument("-q", "--quiet", action='store_true', help='Suppress output.')
    args = parser.parse_args(args=args)
@@ -104,38 +106,44 @@ def main(args=None, output_file=None):
    if args.fix:
       mode = "r+b"
 
+   header_start = 0x7F00
+   min_size = 0x8000
+   if args.mode == "hirom":
+      header_start = 0xFF00
+      min_size = 0x10000
+
    with open(args.path, mode) as f:
       f.seek(0, os.SEEK_END)
       mprint(f"File size: {f.tell()} bytes")
 
-      validation_error = validate_sfc(f)
+      validation_error = validate_sfc(f, min_size)
       if validation_error:
          mprint(f"Validation error: {validation_error}")
          mprint("Does this file have an SMC header? Those are not supported.")
          return
 
       size_header, full_size = compute_romsize(f.tell())
       mprint(f"Computed size header value: {size_header}")
-      f.seek(0xFFD7, os.SEEK_SET)
+      f.seek(header_start + 0xD7, os.SEEK_SET)
       mprint(f"Current size header value: {f.read(1)[0]}")
       mprint(f"Full size: {full_size//1024} KiB")
 
       if args.fix:
          pad_file(f, full_size)
-         f.seek(0xFFD7, os.SEEK_SET)
+         f.seek(header_start + 0xD7, os.SEEK_SET)
          f.write(bytes([size_header]))
 
-      f.seek(0xFFDC, os.SEEK_SET)
+      f.seek(header_start + 0xDC, os.SEEK_SET)
       current_checksum_bytes = f.read(4)
       mprint(f"Current checksum bytes: {format_checksum_bytes(current_checksum_bytes)}")
 
-      checksum = calc_checksum(f)
+      checksum = calc_checksum(f, header_start)
       xchecksum = checksum ^ 0xFFFF
       checksum_bytes = bytes([xchecksum & 0xFF, xchecksum >> 8, checksum & 0xFF, checksum >> 8])
       mprint(f"Computed checksum bytes: {format_checksum_bytes(checksum_bytes)}")
 
       if args.fix:
-         f.seek(0xFFDC, os.SEEK_SET)
+         f.seek(header_start + 0xDC, os.SEEK_SET)
          f.write(checksum_bytes)
 
 if __name__ == "__main__":

tool-src/sneschk/sneschk_test.py

@@ -32,15 +32,15 @@ def create_sfc_tmp(self, size):
    # output which may be an arbitrary file size.
    def test_padding(self):
       with self.create_sfc_tmp(80000) as f: pass
-      output = self.call_sneschk([SFC_TMP_FILE])
+      output = self.call_sneschk([SFC_TMP_FILE, "-m", "hirom"])
       self.assertIn("File size: 80000", output)
       self.assertIn("Computed size header value: 7", output)
       self.assertIn("Current size header value: 0", output)
       self.assertIn("Full size: 128 KiB", output)
       self.assertNotIn("bytes of zero-padding", output)
       self.assertEqual(os.path.getsize(SFC_TMP_FILE), 80000)
 
-      output = self.call_sneschk([SFC_TMP_FILE, "--fix"])
+      output = self.call_sneschk([SFC_TMP_FILE, "--fix", "-m", "hirom"])
       self.assertIn("File size: 80000", output)
       self.assertIn(f"Writing {131072 - 80000} bytes of zero-padding", output)
       self.assertEqual(os.path.getsize(SFC_TMP_FILE), 131072)
@@ -57,15 +57,15 @@ def test_padding(self):
    # It's tricky to have a real validation.
    def test_validation(self):
       with self.create_sfc_tmp(0) as f: pass
-      output = self.call_sneschk([SFC_TMP_FILE])
+      output = self.call_sneschk([SFC_TMP_FILE, "-m", "hirom"])
       self.assertIn("file is too small to contain a valid cartridge header", output)
 
       with self.create_sfc_tmp(65535) as f: pass
-      output = self.call_sneschk([SFC_TMP_FILE])
+      output = self.call_sneschk([SFC_TMP_FILE, "-m", "hirom"])
       self.assertIn("file is too small to contain a valid cartridge header", output)
 
       with self.create_sfc_tmp(65536) as f: pass
-      output = self.call_sneschk([SFC_TMP_FILE])
+      output = self.call_sneschk([SFC_TMP_FILE, "-m", "hirom"])
       self.assertIn("Current checksum bytes: 00 00 00 00", output)
 
       os.remove(SFC_TMP_FILE)
@@ -93,11 +93,11 @@ def test_checksum(self):
       ccs = cs ^ 0xFFFF
       csformatted = self.format_byte_string([ccs & 0xFF, ccs >> 8, cs & 0xFF, cs >> 8])
 
-      output = self.call_sneschk([SFC_TMP_FILE])
+      output = self.call_sneschk([SFC_TMP_FILE, "-m", "hirom"])
       self.assertIn("Current checksum bytes: 11 11 11 11", output)
       self.assertIn(f"Computed checksum bytes: {csformatted}", output)
 
-      output = self.call_sneschk([SFC_TMP_FILE, "--fix"])
+      output = self.call_sneschk([SFC_TMP_FILE, "--fix", "-m", "hirom"])
 
       # The extra +7 is the ROM size header byte set by --fix
       cs = (1 + 2  + 3 + 4 + 0xFF * 266 + 0xFF*2 + 7 + 10 * 16384) & 0xFFFF

tools/sneschk.bat

@@ -1,3 +1,3 @@
 @REM Windows should pick this up with the raw name "sneschk" without the extension.
 @REM Forward to the Python script with the Windows py launcher.
-py %SNESKIT%/tools/sneschk.py %*
+@py %SNESKIT%/tools/sneschk.py %*