[kernel]

# =============================================================================
# KERNEL (FRAMEWORK FILE)                                    VERSION 2026-04-04
# =============================================================================
# You cannot modify this file.  The kernel implements essential operations
# that the compiler depends upon.  The funcs marked as "chombit" are
# implemented in a separate file called "kernel.casm".  The funcs marked as
# "intrinsic" are generated directly by the compiler.

type char is byte

type string is char[]

# -----------------------------------------------------------------------------
# If a class extends from class_id_base, then you can use class_id() with it.
class class_id_base
end class

# -----------------------------------------------------------------------------
# Array whose elements are 1 byte in size
class array_1
  func copy_from(target_index: int, source: array_1, source_index: int,
  | num_elements: int)
    chombit
  end func
end class

# -----------------------------------------------------------------------------
# Array whose elements are 2 bytes in size
class array_2
  func copy_from(target_index: int, source: array_2, source_index: int,
  | num_elements: int)
    chombit
  end func
end class

# -----------------------------------------------------------------------------
# Array whose elements are 4 bytes in size
class array_4
  func copy_from(target_index: int, source: array_4, source_index: int,
  | num_elements: int)
    chombit
  end func
end class

# -----------------------------------------------------------------------------
# Array whose elements are pointers
class array_p
  func copy_from(target_index: int, source: array_p, source_index: int,
  | num_elements: int)
    chombit
  end func
end class

# -----------------------------------------------------------------------------
module math
  func abs(x: int): int
    intrinsic
  end func

  func sign(x: int): int
    intrinsic
  end func

  func bit_and(x: int, y: int): int
    intrinsic
  end func

  func bit_or(x: int, y: int): int
    intrinsic
  end func

  func bit_xor(x: int, y: int): int
    intrinsic
  end func

  func bit_not(x: int): int
    intrinsic
  end func

  func shift_left(value: int, shift_amount: int): int
    intrinsic
  end func

  func shift_right_signed(value: int, shift_amount: int): int
    intrinsic
  end func

  func shift_right_unsigned(value: int, shift_amount: int): int
    intrinsic
  end func
end module

# -----------------------------------------------------------------------------
module kernel
  # The text console uses 8 x 8 tiles, with room for 40 rows and 28 cols,
  # however its tilemap grid has 64 rows x 32 cols = 2048 pairs.
  # (There are 24 unused columns on the right and 4 unused rows on the bottom.)
  inset console_grid: ^pair[size 2048] located at $10_0000 # ..$10_0fff

  # The kernel::scratch_bytes array is a general purpose buffer.  Any function
  # may use it, but should assume that other function calls will overwrite it.
  inset scratch_bytes: char[size 32] located at $d0_00a0 # ..$d0_00bf

  func trace_num(id: byte)
    intrinsic
  end func

  func trace(message: string)
    intrinsic
  end func

  func fail(message: string)
    intrinsic
  end func

  func sleep()
    intrinsic
  end func

  # Copies the specified number of bytes from source to dest.
  # It is okay for the memory ranges to overlap.
  func copy_memory_bytes(target: int, source: int, num_bytes: int)
    chombit
  end func

  func set_memory_bytes(target: int, value: byte, num_bytes: int)
    chombit
  end func

  func set_memory_pairs(target: int, value: pair, num_pairs: int)
    chombit
  end func

  func compare_strings(a: char[], a_size: int, b: char[], b_size: int): int
    chombit
  end func

  func index_of_string(s: char[], s_size: int, pattern: char[], pattern_size: int): int
    chombit
  end func

  func collect_garbage()
    chombit
  end func
end module