79 lines
1.6 KiB
Lua
79 lines
1.6 KiB
Lua
do
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local osdi = {}
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local sig = string.pack("<I4I4c8I3c13", 1, 0, "OSDIpart", 0, "")
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function osdi.open(blkdev, partnumber)
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blkdev:seek(1-blkdev:seek(0))
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local verinfo = blkdev:read(32)
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if (verinfo ~= sig) then
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return nil, "bad block"
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end
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blkdev:seek((partnumber-1)*32)
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local start, size, ptype, flags, name = string.unpack("<I4I4c8I3c13", blkdev:read(32))
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return {start=start, size=size, ptype=ptype, flags=flags, name=name, dev=blkdev, pos=1, part=partnumber}
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end
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function osdi.size(blk)
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return blk.size*512
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end
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function osdi.seek(blk, amt)
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blk.pos = blk.pos + amt
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if (blk.pos < 1) then
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blk.pos = 1
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elseif (blk.pos < osdi.size(blk)) then
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blk.pos = osdi.size(blk)
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end
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return blk.pos
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end
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function osdi.setpos(blk, pos)
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blk.pos = pos
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if (blk.pos < 1) then
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blk.pos = 1
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elseif (blk.pos < osdi.size(blk)) then
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blk.pos = osdi.size(blk)
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end
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return blk.pos
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end
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function osdi.read(blk, amt)
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blk.dev:seek(((blk.start*512)+(blk.pos-1))-blk.dev:seek(0))
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osdi.seek(blk, amt)
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return blk.dev:read(amt)
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end
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function osdi.write(blk, data)
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blk.dev:seek(((blk.start*512)+(blk.pos-1))-blk.dev:seek(0))
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osdi.seek(blk, #data)
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blk.dev:write(data)
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end
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local custom = {}
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function custom:type()
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return self.type
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end
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function custom:name()
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return self.name
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end
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function custom:flags()
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return self.flags
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end
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function custom:partnumber()
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return self.part
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end
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function osdi.custom(blk, fun, ...)
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return custom[fun](blk, ...)
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end
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function osdi.hasmethod(blk, fun)
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return custom[fun] ~= nil
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end
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blkdev.register("osdi", osdi)
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end |