545 lines
19 KiB
Python
545 lines
19 KiB
Python
#!/usr/bin/env python3
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#
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# Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
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# Copyright 2017, Ember Arlynx
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# Copyright (c) 2022 Google LLC
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# Copyright (c) 2022 Antmicro
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#
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# SPDX-License-Identifier: BSD-2-Clause
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#
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# This script is intended to work as a Rust-specific copy of syscall_stub_gen.py
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# Use it with sel4-sys crate to allow Rust applications interface with the seL4 API.
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from argparse import ArgumentParser
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import sys
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import syscall_stub_gen
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TYPES = {
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8: "u8",
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16: "u16",
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32: "u32",
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64: "u64"
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}
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def translate_expr(name):
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if name == "type":
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return "type_"
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return name
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def translate_type(name):
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type_trans = {
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"int": "isize",
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"seL4_Uint8": "u8",
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"seL4_Uint16": "u16",
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"seL4_Uint32": "u32",
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"seL4_Uint64": "u64",
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"seL4_Bool": "u8",
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"seL4_CapData_t": "seL4_CapData",
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"seL4_PrioProps_t": "seL4_PrioProps",
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"seL4_CapRights_t": "seL4_CapRights",
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"seL4_RISCV_Page_GetAddress_t": "seL4_RISCV_Page_GetAddress",
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}
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if name in type_trans:
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return type_trans[name]
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else:
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return name
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def rust_render_parameter_name(param_type, name, mutable_ref=False):
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"""
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Return a string of Rust code that would be used in a function
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parameter declaration.
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"""
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if type(param_type) in [syscall_stub_gen.Type, syscall_stub_gen.CapType, syscall_stub_gen.StructType, syscall_stub_gen.BitFieldType]:
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name = translate_expr(name)
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return "%s: %s" % (name, translate_type(param_type.name))
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elif type(param_type) is syscall_stub_gen.PointerType:
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return "%s: *%s %s" % (
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translate_expr(name),
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"mut" if mutable_ref else "const",
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translate_type(param_type.name))
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else:
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raise Exception("Unsupported type")
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def rust_double_word_expression(param_type, var_name, word_num, word_size):
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assert word_num == 0 or word_num == 1
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if word_num == 0:
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return "{1} as {0}".format(TYPES[param_type.size_bits], var_name)
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elif word_num == 1:
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return "{1}.wrapping_shr({2}) as {0}".format(TYPES[param_type.size_bits], var_name,
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word_size)
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def rust_expression(param_type, var_name, word_num=0, member_name=None):
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"""
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Return code for an expression that gets word 'word_num'
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of the provided type.
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"""
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if type(param_type) is syscall_stub_gen.BitFieldType:
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return "%s.words[%d]" % (var_name, word_num)
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elif type(param_type) is syscall_stub_gen.StructType:
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assert word_num < param_type.size_bits // param_type.wordsize
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# Multiword structure.
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assert param_type.pass_by_reference()
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return "(*%s).%s" % (var_name, member_name[word_num])
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elif type(param_type) is syscall_stub_gen.PointerType:
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assert word_num == 0
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return "unsafe { *%s }" % var_name
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elif type(param_type) in [syscall_stub_gen.Type, syscall_stub_gen.CapType]:
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assert word_num == 0
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return "%s" % var_name
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else:
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raise Exception("Unsupported type")
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def generate_param_list(input_params, output_params):
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# Generate parameters
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params = []
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for param in input_params:
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t = param.type
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if not t.pass_by_reference():
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params.append(rust_render_parameter_name(t, param.name))
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else:
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params.append(rust_render_parameter_name(t.pointer(), param.name, mutable_ref=False))
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for param in output_params:
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# We drop params that aren't pass_by_reference deliberately
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if param.type.pass_by_reference():
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params.append(rust_render_parameter_name(
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param.type.pointer(), param.name, mutable_ref=True))
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return ", ".join(params)
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def generate_marshal_expressions(params, num_mrs, structs, wordsize):
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"""
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Generate marshalling expressions for the given set of inputs.
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We return a list of expressions; one expression per word required
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to marshal all the inputs.
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"""
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def generate_param_code(param, first_bit, num_bits, word_array, wordsize):
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"""
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Generate code to marshal the given parameter into the correct
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location in the message.
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'word_array' is an array of the final contents of the message.
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word_array[k] contains what should be placed in the k'th message
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register, and is an array of expressions that will (eventually)
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be bitwise-or'ed into it.
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"""
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target_word = first_bit // wordsize
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target_offset = first_bit % wordsize
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# double word type
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if param.type.double_word:
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word_array[target_word].append(
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rust_double_word_expression(param.type, param.name, 0, wordsize))
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word_array[target_word +
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1].append(rust_double_word_expression(param.type, param.name, 1, wordsize))
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return
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# Single full word?
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if num_bits == wordsize:
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assert target_offset == 0
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expr = rust_expression(param.type, param.name)
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word_array[target_word].append(expr)
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return
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# Part of a word?
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if num_bits < wordsize:
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expr = rust_expression(param.type, param.name)
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expr = "(%s & %#x)" % (expr, (1 << num_bits) - 1)
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if target_offset:
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expr = "(%s as seL4_Word).wrapping_shl(%d)" % (expr, target_offset)
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word_array[target_word].append(expr)
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return
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# Multiword array
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assert target_offset == 0
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num_words = num_bits // wordsize
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for i in range(num_words):
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expr = rust_expression(param.type, param.name, i,
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syscall_stub_gen.struct_members(param.type, structs))
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word_array[target_word + i].append(expr)
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# Get their marshalling positions
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positions = syscall_stub_gen.get_parameter_positions(params, wordsize)
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# Generate marshal code.
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words = [[] for _ in range(num_mrs, syscall_stub_gen.MAX_MESSAGE_LENGTH)]
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for (param, first_bit, num_bits) in positions:
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generate_param_code(param, first_bit, num_bits, words, wordsize)
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# Return list of expressions.
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return [" | ".join(map(lambda x: "(" + translate_expr(x) + " as seL4_Word)", x))
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for x in words if len(x) > 0]
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def generate_unmarshal_expressions(params, wordsize):
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"""
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Generate unmarshalling expressions for the given set of outputs.
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We return a list of list of expressions; one list per variable, containing
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expressions for the words in it that must be unmarshalled. The expressions
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will have tokens of the form:
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"%(w0)s"
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in them, indicating a read from a word in the message.
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"""
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def unmarshal_single_param(first_bit, num_bits, wordsize):
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"""
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Unmarshal a single parameter.
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"""
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first_word = first_bit // wordsize
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bit_offset = first_bit % wordsize
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# Multiword type?
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if num_bits > wordsize:
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result = []
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for x in range(num_bits // wordsize):
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result.append("%%(w%d)s" % (x + first_word))
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return result
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# Otherwise, bit packed.
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if num_bits == wordsize:
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return ["%%(w%d)s" % first_word]
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elif bit_offset == 0:
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return ["(%%(w%d)s & %#x)" % (
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first_word, (1 << num_bits) - 1)]
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else:
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return ["(%%(w%d)s.wrapping_shr(%d)) & %#x" % (
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first_word, bit_offset, (1 << num_bits) - 1)]
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# Get their marshalling positions
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positions = syscall_stub_gen.get_parameter_positions(params, wordsize)
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# Generate the unmarshal code.
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results = []
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for (param, first_bit, num_bits) in positions:
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results.append((param, unmarshal_single_param(first_bit, num_bits, wordsize)))
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return results
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def generate_result_struct(interface_name, method_name, output_params):
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# Do we actually need a structure?
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if not syscall_stub_gen.is_result_struct_required(output_params):
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return None
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# Generate the structure:
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#
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# #[repr(C)]
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# #[derive(Debug, Clone, Copy, PartialEq, Eq)]
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# pub struct seL4_SchedContext_Consumed {
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# pub error: isize,
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# pub consumed: seL4_Time,
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result = []
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result.append("#[repr(C)]")
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result.append("#[derive(Debug, Clone, Copy, PartialEq, Eq)]")
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result.append("pub struct %s_%s {" % (interface_name, method_name))
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result.append("\tpub error: isize,")
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for i in output_params:
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if not i.type.pass_by_reference():
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result.append("\tpub %s," % rust_render_parameter_name(i.type, i.name))
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result.append("}")
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result.append("")
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return "\n".join(result)
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def generate_stub(arch, wordsize, interface_name, method_name, method_id, input_params, output_params, structs, use_only_ipc_buffer, comment, mcs):
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result = []
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if use_only_ipc_buffer:
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num_mrs = 0
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else:
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if mcs and "%s-mcs" % arch in syscall_stub_gen.MESSAGE_REGISTERS_FOR_ARCH:
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num_mrs = syscall_stub_gen.MESSAGE_REGISTERS_FOR_ARCH["%s-mcs" % arch]
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else:
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num_mrs = syscall_stub_gen.MESSAGE_REGISTERS_FOR_ARCH[arch]
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# Split out cap parameters and standard parameters
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standard_params = []
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cap_params = []
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for x in input_params:
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if isinstance(x.type, syscall_stub_gen.CapType):
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cap_params.append(x)
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else:
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standard_params.append(x)
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# Determine if we are returning a structure, or just the error code.
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returning_struct = False
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results_structure = generate_result_struct(interface_name, method_name, output_params)
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if results_structure:
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return_type = "%s_%s" % (interface_name, method_name)
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returning_struct = True
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else:
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return_type = "seL4_Result"
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#
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# Print doxygen comment.
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#
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result.append(comment)
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#
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# Print function header.
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#
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# #[inline(always)]
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# #[macros::derive_test_wrapper]
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# pub unsafe fn seL4_Untyped_Retype(...) -> seL4_Result
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# {
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#
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result.append("#[inline(always)]")
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result.append("pub unsafe fn %s_%s(%s) -> %s" % (interface_name, method_name,
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generate_param_list(input_params, output_params), return_type))
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result.append("{")
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#
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# Get a list of expressions for our caps and inputs.
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#
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input_expressions = generate_marshal_expressions(standard_params, num_mrs,
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structs, wordsize)
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cap_expressions = [x.name for x in cap_params]
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service_cap = cap_expressions[0]
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cap_expressions = cap_expressions[1:]
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#
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# Setup variables we will need.
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#
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if returning_struct:
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result.append("\tlet mut result: %s = ::core::mem::zeroed();" % return_type)
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result.append("\tlet tag = seL4_MessageInfo::new(InvocationLabel::%s as seL4_Word, 0, %d, %d);" % (
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method_id, len(cap_expressions), len(input_expressions)))
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for i in range(num_mrs):
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result.append("\tlet mut mr%d: seL4_Word = 0;" % i)
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result.append("")
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#
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# Copy capabilities.
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#
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# /* Setup input capabilities. */
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# seL4_SetCap(i, cap);
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#
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if len(cap_expressions) > 0:
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result.append("\t/* Setup input capabilities. */")
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for i in range(len(cap_expressions)):
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result.append("\tseL4_SetCap(%d, %s);" % (i, cap_expressions[i]))
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result.append("")
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#
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# Copy in the inputs.
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#
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# /* Marshal input parameters. */
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# mr0 = (start_offset as seL4_Word) as seL4_Word;
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# ...
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# seL4_SetMR(i, v);
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# ...
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#
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if max(num_mrs, len(input_expressions)) > 0:
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result.append("\t/* Marshal and initialize parameters. */")
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# Initialise in-register parameters
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for i in range(num_mrs):
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if i < len(input_expressions):
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result.append("\tmr%d = %s as seL4_Word;" % (i, input_expressions[i]))
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else:
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result.append("\tmr%d = 0 as seL4_Word;" % i)
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# Initialise buffered parameters
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for i in range(num_mrs, len(input_expressions)):
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expression = translate_expr(input_expressions[i])
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result.append("\tseL4_SetMR(%d, %s);" % (i, expression))
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result.append("")
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#
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# Generate the call.
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#
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if use_only_ipc_buffer:
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result.append("\t/* Perform the call. */")
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result.append("\tlet output_tag = seL4_Call(%s, tag);" % service_cap)
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else:
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result.append("\t/* Perform the call, passing in-register arguments directly. */")
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result.append("\tlet output_tag = seL4_CallWithMRs(%s, tag," % (service_cap))
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result.append("\t\t%s);" % ', '.join(
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("&mut mr%d" % i) for i in range(num_mrs)))
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#
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# Prepare the result.
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#
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if returning_struct:
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result.append("\tresult.error = output_tag.get_label() as _;")
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else:
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result.append("\tlet error: seL4_Error = output_tag.get_label().into();")
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result.append("")
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if not use_only_ipc_buffer:
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result.append("\t/* Unmarshal registers into IPC buffer on error. */")
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result.append("\tif error != seL4_Error::seL4_NoError {")
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for i in range(num_mrs):
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result.append("\t\tseL4_SetMR(%d, mr%d);" % (i, i))
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if returning_struct:
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result.append("\t\treturn result;")
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result.append("\t}")
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result.append("")
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#
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# Generate unmarshalling code.
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#
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if len(output_params) > 0:
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result.append("\t/* Unmarshal result. */")
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source_words = {}
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for i in range(syscall_stub_gen.MAX_MESSAGE_LENGTH):
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if i < num_mrs:
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source_words["w%d" % i] = "mr%d" % i
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else:
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source_words["w%d" % i] = "seL4_GetMR(%d)" % i
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unmashalled_params = generate_unmarshal_expressions(output_params, wordsize)
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for (param, words) in unmashalled_params:
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param.name = translate_expr(param.name)
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if param.type.pass_by_reference():
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members = syscall_stub_gen.struct_members(param.type, structs)
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for i in range(len(words)):
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result.append("\t(*%s).%s = %s;" %
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(param.name, members[i], words[i] % source_words))
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else:
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if param.type.double_word:
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result.append("\tresult.%s = (%s as %s) + ((%s as %s).wrapping_shr(32));" %
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(param.name, words[0] % source_words, TYPES[64],
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words[1] % source_words, TYPES[64]))
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else:
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for word in words:
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if type(param.type) is syscall_stub_gen.StructType:
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result.append("\tresult.%s = %s { words: [%s] };" % (
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param.name, param.type.name, word % source_words))
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else:
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result.append("\tresult.%s = %s as %s;" % (param.name, word %
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source_words, translate_type(param.type.name)))
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#
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# }
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#
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result.append("\tresult" if returning_struct else "\terror.into()")
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result.append("}")
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return "\n".join(result) + "\n"
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def generate_stub_file(arch, input_files, output_file, use_only_ipc_buffer, mcs, args):
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"""
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Generate a header file containing system call stubs for seL4.
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"""
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result = []
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# Ensure architecture looks sane.
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if arch not in syscall_stub_gen.WORD_SIZE_BITS_ARCH.keys():
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raise Exception(f"Invalid architecture: {arch}")
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wordsize = syscall_stub_gen.WORD_SIZE_BITS_ARCH[arch]
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data_types = syscall_stub_gen.init_data_types(wordsize)
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arch_types = syscall_stub_gen.init_arch_types(wordsize, args)
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# Parse XML
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methods = []
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structs = []
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for infile in input_files:
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method, struct, _ = syscall_stub_gen.parse_xml_file(infile, data_types + arch_types[arch])
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methods += method
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structs += struct
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# Print header.
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result.append("""
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/*
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* Automatically generated system call stubs.
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*/
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""")
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#
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# Generate structures needed to return results back to the user.
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#
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# We can not use pass-by-reference (except for really large objects), as
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# the verification framework does not support them.
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#
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result.append("/*")
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result.append(" * Return types for generated methods.")
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result.append(" */")
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for (interface_name, method_name, _, _, output_params, _, _) in methods:
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results_structure = generate_result_struct(interface_name, method_name, output_params)
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if results_structure:
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result.append(results_structure)
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#
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# Generate the actual stub code.
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#
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result.append("/*")
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result.append(" * Generated stubs.")
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result.append(" */")
|
|
for (interface_name, method_name, method_id, inputs, outputs, condition, comment) in methods:
|
|
if condition != "":
|
|
if condition == "(!defined(CONFIG_KERNEL_MCS) && defined(CONFIG_ENABLE_SMP_SUPPORT))":
|
|
condition = 'all(not(feature = "CONFIG_KERNEL_MCS"), feature = "CONFIG_ENABLE_SMP_SUPPORT")'
|
|
elif condition:
|
|
condition = condition.replace('defined', '')
|
|
condition = condition.replace('(', '')
|
|
condition = condition.replace(')', '')
|
|
if 'CONFIG_' in condition:
|
|
condition = 'feature = "' + condition + '"'
|
|
if '!' in condition:
|
|
condition = 'not(%s)' % condition.replace('!', '')
|
|
if condition:
|
|
result.append("#[cfg(%s)]" % condition)
|
|
result.append(generate_stub(arch, wordsize, interface_name, method_name,
|
|
method_id, inputs, outputs, structs, use_only_ipc_buffer, comment, mcs))
|
|
|
|
result.append("")
|
|
|
|
# Write the output
|
|
output = open(output_file, "w")
|
|
output.write("\n".join(result))
|
|
output.close()
|
|
|
|
|
|
def process_args():
|
|
usage_str = """
|
|
%(prog)s [OPTIONS] [FILES] """
|
|
epilog_str = """
|
|
|
|
"""
|
|
parser = ArgumentParser(description='seL4 System Call Stub Generator.',
|
|
usage=usage_str,
|
|
epilog=epilog_str)
|
|
parser.add_argument("-o", "--output", dest="output", default="/dev/stdout",
|
|
help="Output file to write stub to. (default: %(default)s).")
|
|
parser.add_argument("-b", "--buffer", dest="buffer", action="store_true", default=False,
|
|
help="Use IPC buffer exclusively, i.e. do not pass syscall arguments by registers. (default: %(default)s)")
|
|
parser.add_argument("-a", "--arch", dest="arch", required=True, choices=syscall_stub_gen.WORD_SIZE_BITS_ARCH,
|
|
help="Architecture to generate stubs for.")
|
|
parser.add_argument("--mcs", dest="mcs", action="store_true",
|
|
help="Generate MCS api.")
|
|
parser.add_argument("--x86-vtx-64-bit-guests", dest="x86_vtx_64bit", action="store_true", default=False,
|
|
help="Whether the vtx VCPU objects need to be large enough for 64-bit guests.")
|
|
|
|
parser.add_argument("files", metavar="FILES", nargs="+",
|
|
help="Input XML files.")
|
|
|
|
return parser
|
|
|
|
|
|
def main():
|
|
parser = process_args()
|
|
args = parser.parse_args()
|
|
# Generate the stubs.
|
|
generate_stub_file(args.arch, args.files, args.output, args.buffer, args.mcs, args)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
sys.exit(main())
|