From 72f653f915efdcf8eebc61c9cf0a8d963fb3fa60 Mon Sep 17 00:00:00 2001
From: "K. Lange" <klange@toaruos.org>
Date: Wed, 14 Nov 2018 12:36:42 +0900
Subject: [PATCH] util/iso.py: wip ISO creation tool

---
 util/iso.py | 278 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 278 insertions(+)
 create mode 100755 util/iso.py

diff --git a/util/iso.py b/util/iso.py
new file mode 100755
index 00000000..4d7221f2
--- /dev/null
+++ b/util/iso.py
@@ -0,0 +1,278 @@
+#!/usr/bin/env python3
+"""
+    Tool for creating ISO 9660 CD images.
+"""
+import array
+import struct
+
+class Structure(object):
+
+    assert_size = -1
+
+    def __init__(self):
+        self.data = {}
+        for field in self.fields:
+            if len(field) > 2:
+                f, s, d = field
+                self.data[s] = d
+            else:
+                f, s = field
+                if f.endswith('s'):
+                    self.data[s] = b""
+                else:
+                    self.data[s] = 0
+        if self.assert_size != -1:
+            assert(len(self) == self.assert_size)
+
+    def __len__(self):
+        return sum([struct.calcsize(f[0]) for f in self.fields])
+
+    def read(self, data, offset):
+
+        def read_struct(fmt,buf,offset):
+            out, = struct.unpack_from(fmt,buf,offset)
+            return out, offset + struct.calcsize(fmt)
+
+        o = offset
+        for field in self.fields:
+            if len(field) > 2:
+                f, s, _ = field
+            else:
+                f, s = field
+            self.data[s], o = read_struct(f, data, o)
+        return o
+
+    def write(self, data, offset):
+
+        def write_struct(fmt, buf, offset, value):
+            struct.pack_into(fmt, buf, offset, value)
+            return offset + struct.calcsize(fmt)
+
+        o = offset
+        for field in self.fields:
+            if len(field) > 2:
+                f, s, _ = field
+            else:
+                f, s = field
+            o = write_struct(f,data,o,self.data[s])
+        return o
+
+def make_time():
+    data = array.array('b',b'\0'*17)
+    struct.pack_into(
+        '4s2s2s2s2s2s2sb',
+        data, 0,
+        b'2018', b'11', b'14', # Year, Month, Day
+        b'12', b'00', b'00', # Hour, Minute, Second
+        b'00', # Hundreths
+        0, # Offset
+    )
+    return bytes(data)
+
+
+class ISOBootRecord(Structure):
+    assert_size = 2048
+    fields = (
+        ('B', 'type_code', 0),
+        ('5s', 'cd001', b'CD001'),
+        ('B', 'version', 1),
+        ('32s', 'boot_system_identifier'),
+        ('32s', 'boot_identifier'),
+        ('1977s', 'boot_record_data'),
+    )
+
+class ISOElToritoBootRecord(ISOBootRecord):
+    assert_size = 2048
+    fields = (
+        ('B', 'type_code', 0),
+        ('5s', 'cd001', b'CD001'),
+        ('B', 'version', 1),
+        ('32s', 'boot_system_identifier',b'EL TORITO SPECIFICATION'),
+        ('32s', 'boot_identifier'),
+        ('<I', 'catalog_lba'),
+        ('1973s', 'boot_record_data'),
+    )
+
+    def set_catalog(self, catalog_lba):
+        self.data['catalog_lba'] = catalog_lba
+
+class ISOPrimaryVolumeDescriptor(Structure):
+    assert_size = 2048
+    fields = (
+        ('B', 'type_code', 1),
+        ('5s', 'cd001', b'CD001'),
+        ('B', 'version', 1),
+        ('B', 'unused_0', 0),
+        ('32s', 'system_id', b' '*32),
+        ('32s', 'volume_id', b'ToaruOS Boot CD'.ljust(32)),
+        ('8s', 'unused_1', b'\0'*8),
+        ('<I', 'volume_space_lsb'),
+        ('>I', 'volume_space_msb'),
+        ('32s', 'unused_2', b'\0'*32),
+        ('<H', 'volume_set_size_lsb', 1),
+        ('>H', 'volume_set_size_msb', 1),
+        ('<H', 'volume_sequence_lsb', 1),
+        ('>H', 'volume_sequence_msb', 1),
+        ('<H', 'logical_block_size_lsb', 2048),
+        ('>H', 'logical_block_size_msb', 2048),
+        ('<I', 'path_table_size_lsb'),
+        ('>I', 'path_table_size_msb'),
+        ('<I', 'type_l_table_lsb'),
+        ('<I', 'optional_type_l_table_lsb'),
+        ('>I', 'type_m_table_msb'),
+        ('>I', 'optional_type_m_table_msb'),
+        ('34s', 'root_entry_data'),
+        ('128s', 'volume_set_identifier', b' '*128),
+        ('128s', 'publisher_identifier', b' '*128),
+        ('128s', 'data_preparer_identifier', b' '*128),
+        ('128s', 'application_identifier',b' '*128),
+        ('38s', 'copyright_file_identifier',b' '*38),
+        ('36s', 'abstract_file_identifier',b' '*36),
+        ('37s', 'bibliographic_file_identifier',b' '*37),
+        ('17s', 'volume_creation_time',make_time()),
+        ('17s', 'volume_modification_time',make_time()),
+        ('17s', 'volume_expiration_time',make_time()),
+        ('17s', 'volume_effective_time',make_time()),
+        ('B', 'file_structure_version'),
+        ('B', 'unused_3', 0),
+        ('512s', 'application_data'),
+        ('653s', 'reserved', b'\0'*653),
+    )
+
+class ISOVolumeDescriptorSetTerminator(Structure):
+    assert_size = 2048
+    fields = (
+        ('B', 'type_code', 0xFF),
+        ('5s', 'cd001', b'CD001'),
+        ('B', 'version', 1),
+        ('2041s', 'unused', b'\0'*2041)
+    )
+
+class ArbitraryData(object):
+
+    def __init__(self, path):
+
+        with open(path,'rb') as f:
+            tmp = f.read()
+            self.data = array.array('b',tmp)
+
+        self.size = len(self.data)
+        while (self.size % 2048):
+            self.size += 1
+
+    def write(self, data, offset):
+        struct.pack_into(str(self.size) + 's', data, offset, self.data.tobytes())
+        return offset + self.size
+
+class ISO9660(object):
+
+    def __init__(self, from_file=None):
+        self.primary_volume_descriptor = ISOPrimaryVolumeDescriptor()
+        self.boot_record = ISOElToritoBootRecord()
+        self.volume_descriptor_set_terminator = ISOVolumeDescriptorSetTerminator()
+        self.el_torito_catalog = ElToritoCatalog()
+
+        if from_file:
+            # Only for a file we produced.
+            with open(from_file, 'rb') as f:
+                tmp = f.read()
+                data = array.array('b', tmp)
+            self.primary_volume_descriptor.read(data, 0x10 * 2048)
+            self.boot_record.read(data, 0x11 * 2048)
+            self.volume_descriptor_set_terminator.read(data, 0x12 * 2048)
+            self.el_torito_catalog.read(data, self.boot_record.data['catalog_lba'] * 2048)
+        else:
+            self.boot_payload = ArbitraryData('cdrom/boot.sys')
+            self.boot_record.set_catalog(0x13)
+            self.el_torito_catalog.initial_entry.data['sector_count'] = 24
+            self.el_torito_catalog.initial_entry.data['load_rba'] = 0x14
+
+    def write(self, file_name):
+        with open(file_name, 'wb') as f:
+            data = array.array('b',b'\0'*(2048*0x14 + self.boot_payload.size))
+            print(len(data))
+            self.primary_volume_descriptor.write(data,0x10 * 2048)
+            self.boot_record.write(data,0x11 * 2048)
+            self.volume_descriptor_set_terminator.write(data,0x12 * 2048)
+            self.el_torito_catalog.write(data,0x13 * 2048)
+            self.boot_payload.write(data,0x14 * 2048)
+            data.tofile(f)
+
+class ElToritoValidationEntry(Structure):
+    assert_size = 0x20
+    fields = (
+        ('B','header_id',1),
+        ('B','platform_id',0),
+        ('<H','reserved_0'),
+        ('24s','id_str',b'\0'*24),
+        ('<H','checksum',0x55aa),
+        ('B','key_55',0x55),
+        ('B','key_aa',0xaa),
+    )
+
+class ElToritoInitialEntry(Structure):
+    assert_size = 0x20
+    fields = (
+        ('B','bootable',0x88),
+        ('B','media_type'),
+        ('<H','load_segment'),
+        ('B','system_type'),
+        ('B','unused_0'),
+        ('<H','sector_count'),
+        ('<I','load_rba'),
+        ('20s','unused_1',b'\0'*20),
+    )
+
+class ElToritoSectionHeader(Structure):
+    assert_size = 0x20
+    fields = (
+        ('B','header_id',0x91),
+        ('B','platform_id',0xEF),
+        ('<H','sections',1),
+        ('28s','id_str',b'\0'*28)
+    )
+
+class ElToritoSectionEntry(Structure):
+    assert_size = 0x20
+    fields = (
+        ('B','bootable',0x88),
+        ('B','media_type'),
+        ('<H','load_segment'),
+        ('B','system_type'),
+        ('B','unused_0'),
+        ('<H','sector_count'),
+        ('<I','load_rba'),
+        ('B','selection_criteria'),
+        ('19s','vendor'),
+    )
+
+class ElToritoCatalog(object):
+
+    def __init__(self):
+        self.validation_entry = ElToritoValidationEntry()
+        self.initial_entry = ElToritoInitialEntry()
+        self.section_header = ElToritoSectionHeader()
+        self.section = ElToritoSectionEntry()
+
+    def read(self, data, offset):
+        o = offset
+        o = self.validation_entry.read(data, o)
+        o = self.initial_entry.read(data, o)
+        o = self.section_header.read(data, o)
+        o = self.section.read(data, o)
+
+    def write(self, data, offset):
+        o = offset
+        o = self.validation_entry.write(data, o)
+        o = self.initial_entry.write(data, o)
+        o = self.section_header.write(data, o)
+        o = self.section.write(data, o)
+
+
+iso = ISO9660()
+#print(iso.el_torito_catalog.validation_entry.data)
+#print(iso.el_torito_catalog.initial_entry.data)
+#print(iso.el_torito_catalog.section_header.data)
+#print(iso.el_torito_catalog.section.data)
+iso.write('test.iso')
+