Fábio Coutada
5ab1b438b4
- initramfs.img, rootfs.img for AArch64 Linux guest - mkdisk.py for disk image creation - initramfs and rootfs directories
80 lines
2.4 KiB
Python
80 lines
2.4 KiB
Python
#!/usr/bin/env python3
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"""
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Generate a virtio-blk disk image for UniversalisOS Linux guest.
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Creates a raw disk image with the UOSVBLK1 header format that
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virtio-blk can detect and serve to the guest.
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Usage:
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python3 mkdisk.py <input_file> <output.img> [--size=SIZE]
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The output image format:
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Offset 0x000: "UOSVBLK1" magic (8 bytes)
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Offset 0x008: data size in bytes (8 bytes, little-endian)
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Offset 0x010: raw sector data (512-byte aligned)
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"""
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import sys
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import os
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import struct
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MAGIC = b"UOSVBLK1"
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SECTOR_SIZE = 512
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def create_disk_image(input_path, output_path, target_size=None):
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"""Create a virtio-blk disk image from an input file."""
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# Read input file
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with open(input_path, 'rb') as f:
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data = f.read()
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# Pad to sector boundary
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if len(data) % SECTOR_SIZE != 0:
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data += b'\x00' * (SECTOR_SIZE - (len(data) % SECTOR_SIZE))
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# Pad to target size if specified
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if target_size and target_size > len(data):
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data += b'\x00' * (target_size - len(data))
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# Create image with header
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header = MAGIC + struct.pack('<Q', len(data)) # magic + size (LE 64-bit)
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# Pad header to sector boundary
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if len(header) % SECTOR_SIZE != 0:
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header += b'\x00' * (SECTOR_SIZE - len(header))
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image = header + data
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# Write output
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with open(output_path, 'wb') as f:
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f.write(image)
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print(f"Disk image created: {output_path}")
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print(f" Input: {input_path} ({len(data)} bytes)")
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print(f" Header: {len(header)} bytes")
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print(f" Total: {len(image)} bytes ({len(image) // 1024} KB)")
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print(f" Sectors: {len(image) // SECTOR_SIZE}")
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def main():
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if len(sys.argv) < 3:
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print(f"Usage: {sys.argv[0]} <input> <output.img> [--size=SIZE]")
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print(f" input: input file (initramfs, rootfs, etc.)")
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print(f" output: output disk image")
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print(f" --size: target size in bytes (optional, pads with zeros)")
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sys.exit(1)
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input_path = sys.argv[1]
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output_path = sys.argv[2]
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target_size = None
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for arg in sys.argv[3:]:
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if arg.startswith('--size='):
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target_size = int(arg.split('=')[1])
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if not os.path.exists(input_path):
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print(f"Error: input file not found: {input_path}")
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sys.exit(1)
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create_disk_image(input_path, output_path, target_size)
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if __name__ == '__main__':
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main()
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